sci.electronics.repair - 23 new messages in 7 topics - digest

sci.electronics.repair
http://groups.google.com/group/sci.electronics.repair?hl=en

sci.electronics.repair@googlegroups.com

Today's topics:

* hi - 2 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/82166adfe1c013ef?hl=en
* Re-winding solenoids. - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/fd7d7813745e3da8?hl=en
* SMPS design ... - 9 messages, 4 authors
http://groups.google.com/group/sci.electronics.repair/t/fafbacc4bb94c7c0?hl=en
* GE rant, and oven controll board problem - 5 messages, 5 authors
http://groups.google.com/group/sci.electronics.repair/t/2e46146acae5f251?hl=en
* NEW UPDATS - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/a1efeaff713ca30b?hl=en
* Composite video from Compaq Armada e500. - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/86cceb3718265fb1?hl=en
* White LED spectrum? - 3 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/7b379dacdacd2dfe?hl=en

==============================================================================
TOPIC: hi
http://groups.google.com/group/sci.electronics.repair/t/82166adfe1c013ef?hl=en
==============================================================================

== 1 of 2 ==
Date: Thurs, Oct 20 2011 10:01 pm
From: "shahzypk@hotmail.com"

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http://fashion1298.blogspot.com

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http://pakihealthpk.blogspot.com

http://dogbreedspk.blogspot.com

http://super1213.blogspot.com

http://fashion1299.blogspot.com

http://mehndipk12.blogspot.com

http://goldandsilverpk.blogspot.com

== 2 of 2 ==
Date: Fri, Oct 21 2011 11:41 pm
From: "shahzypk@hotmail.com"

Just Visite These Sites

http://fashion1298.blogspot.com

http://cricketin2011.blogspot.com

http://fashion4paki.blogspot.com

http://hollywood1233.blogspot.com

http://hotbollywoodactressesno1.blogspot.com

http://pakihealthpk.blogspot.com

http://dogbreedspk.blogspot.com

http://super1213.blogspot.com

http://fashion1299.blogspot.com

http://mehndipk12.blogspot.com

http://goldandsilverpk.blogspot.com

==============================================================================
TOPIC: Re-winding solenoids.
http://groups.google.com/group/sci.electronics.repair/t/fd7d7813745e3da8?hl=en
==============================================================================

== 1 of 2 ==
Date: Fri, Oct 21 2011 3:22 am
From: Jeffrey Angus

On 10/20/2011 9:51 PM, josephkk wrote:
> Just for grins, Jeff 1.0 have you tried spice models of the rectifier
> solenoid at 480 and 240? It may help you see something you may have
> missed.

It hadn't occurred to me to do that. It's pretty much of a static
operation. You apply power, it pulls up on the armature. When the
mechanism changes position, an auxiliary switch disconnects the
solenoid.

> BTW i expect you will replace the bridge with one appropriated
> rated for the solenoid?

The original bridge was dealing with 480 vac @ 5.2 amps. The new
coil will present a load of about 4 amps @ 240 vac. It's not an
issue.

Jeff-1.0

--
"Everything from Crackers to Coffins"

== 2 of 2 ==
Date: Fri, Oct 21 2011 5:08 pm
From: Jeff Liebermann

On Fri, 21 Oct 2011 05:22:39 -0500, Jeffrey Angus <grendelair@aim.com>
wrote:

>On 10/20/2011 9:51 PM, josephkk wrote:
>> Just for grins, Jeff 1.0 have you tried spice models of the rectifier
>> solenoid at 480 and 240? It may help you see something you may have
>> missed.
>
>It hadn't occurred to me to do that.

See <jm9r97l1ngmq2e456e9fqi0m324u82rvkj@4ax.com>
where I mumbled:
At 60Hz, that's 276 uF. 330uf 600VDC caps should work.
I'm not very confident with my crude approximations. Therefore,
I would feed the model to LTSpice and see what it's really going
to do.
<http://www.linear.com/designtools/software/#LTspice>
Look for current and voltage spikes.

>It's pretty much of a static
>operation. You apply power, it pulls up on the armature. When the
>mechanism changes position, an auxiliary switch disconnects the
>solenoid.

You can specify an input pulse with:

Syntax: Ixxx n+ n- PULSE(Ioff Ion Tdelay Trise Tfall Ton Tperiod
Ncycles)

There are also other circuit simulators that might work:
<http://www.falstad.com/circuit/> (Java)

Make me rich and I'll do the recti-fire and sol-e-void model for you.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

==============================================================================
TOPIC: SMPS design ...
http://groups.google.com/group/sci.electronics.repair/t/fafbacc4bb94c7c0?hl=en
==============================================================================

== 1 of 9 ==
Date: Fri, Oct 21 2011 3:58 am
From: "petrus bitbyter"

"Arfa Daily" <arfa.daily@ntlworld.com> schreef in bericht
news:l5Knq.8102$Qv2.4777@newsfe29.ams2...
>
>
> "N_Cook" <diverse@tcp.co.uk> wrote in message
> news:j7jb95$j6l$1@dont-email.me...
>> Arfa Daily <arfa.daily@ntlworld.com> wrote in message
>> news:p04nq.10308$tk5.3106@newsfe13.ams2...
>>> I've been given a number of switchers to look at, by a company that I do
>>> other work for. The one that concerns me here, is an open frame type,
>> single
>>> 12 volt output at, I would guess, 3 - 4 amps. It appears to be a very
>> simple
>>> design, in that the chopper drive circuit is discrete, employing two
>> bipolar
>>> transistors as an astable. The output of this is fed pretty much
>>> directly
>> to
>>> the gate of a single FET. In the drain of the FET, is a single primary
>>> winding up to the raw rail from the input bridge.
>>>
>>> Across that primary, is a network comprising a 330pF 2 Kv disc ceramic
>> cap,
>>> and two 3 watt cement-body resistors, all in series. On every one of the
>>> examples sent to me, the two resistors are chalky and very discoloured
>>> to
>>> the point where you can't read the bands. On some of them, one of the
>>> resistors is open. Of the remaining resistors, they all seem to go
>>> around
>>> 150 ohms, so I'm taking that to be the original value, based on the fact
>>> that this type of resistor doesn't usually go low, and some of them have
>>> gone open. Make no mistake, these resistors look like they run very hot
>>> normally, to the point where the solder on their joints has crystalised,
>> and
>>> on some, scorch damage has been done to the print, and the substrate.
>>>
>>> Now here's the bit that I am finding puzzling. If you take one where one
>> or
>>> both of the resistors has gone open, the supply works just fine. Loaded
>>> up
>>> to a couple of amps, it runs cool and the regulation is good. The
>> switching
>>> FET is barely breaking a sweat, as you would expect. So I went ahead and
>>> replaced the resistors with a pair of 150 ohm 3 watt types that look
>> pretty
>>> much identical to the originals - even down to the blue body colour. The
>> cap
>>> checks ok for value and leakage. With the resistors in place, the supply
>>> still works just fine, except that it now runs pretty hot, even when
>>> unloaded. The FET is a lot hotter than it was before. The resistors get
>> well
>>> hot, as I was expecting, given the condition of the originals, but with
>> the
>>> supply loaded up to a couple of amps, they get very hot, and the FET
>> becomes
>>> uncomfortably hot as well.
>>>
>>> As far as I can make out, doing some on-line reading about SMPS design,
>> this
>>> network across the transformer primary, is a simple snubber (as opposed
>>> to
>> a
>>> clamp or combination clamp and snubber as is also sometimes found in
>>> this
>>> position). Texts suggest that its purpose is to limit the level of
>>> voltage
>>> spikes at the switching point, to keep the switching device operating
>> within
>>> its SOA and reduce dissipation, which seems a fair enough comment.
>> However,
>>> quite the reverse appears to be true. The whole supply seems a lot
>>> happier
>>> with that network 'not there' as it effectively is, when the resistors
>>> are
>>> open.
>>>
>>> So has anyone got any good thoughts as to what is going on here ? I've
>> done
>>> a great deal of repairs to switchers over the years, and am well versed
>> with
>>> the principles of operation and repair, but I freely admit that I am not
>>> a
>>> designer in this field, so I'm at a bit of a loss as to whether it's
>>> just
>>> generally a poor design, or whether there's something else wrong that
>>> I'm
>>> missing. As those components were originally designed in, and are
>>> clearly
>>> faulty now, they need to be replaced, but the fact that the supply seems
>> to
>>> run less efficiently when they are in place, feels altogether
>>> counter-intuitive
>>>
>>> Arfa
>>>
>>
>>
>> What happens if you double the R and halve the C ?
>
> Don't know. However, these are a commercial item that I am repairing for a
> company, and as they are, is as they were designed, and I guess the
> company that wants me to mend them, would want them left as designed and
> approved.
>
> As it happens, today I got back to doing some more work on them, and this
> time, the situation didn't seem half as bad, which I also can't figure. I
> used the same mains isolation transformer to run them, and exactly the
> same load - a couple of low voltage halogen lamps totaling 40 watts.
> Today, the FET got no hotter under these conditions, than it did with no
> load. In fact, it stayed quite cool. Replacement resistors still ran hot,
> as I'm sure that they must be expected to, given that they are rated at 3
> watts each, but not so hot that you would feel uncomfortable about them
> over dissipating. This has left me a bit non-plussed. Something must be
> different between what I was doing Monday, and what I did today, but I
> can't figure what.
>
> As to them generating high levels of RF, there is certainly no evidence on
> a 'scope, of any RF on the switching waveform. There are a couple of
> radios on in the workshop all the time, one of which is an HF radio
> usually on 10 metres, and the other is a weather sat VHF one. Neither
> showed any signs of picking up anything nasty whilst any of the supplies
> was running.
>
> The nominal switching frequency is around 50 kHz but on the rising edge,
> there is a very tall very narrow spike when the resistors are burnt out.
> When they are replaced, the spike is still there, but quite a lot smaller,
> so I guess that the purpose of the network is to reduce the level of that
> spike to get it down within the ratings of the switching FET. Because the
> spike is very fast and narrow, I guess that the 330pF will have a much
> smaller Xc to that component of the waveform.
>
> Arfa
>>
>>

Didn't you walk right into the problem? It seems that by a yet unknown cause
the circuit sometimes runs into some state that makes it oscillate or in
some other way fries the resistors. This kind of intermitted faults are the
most difficult to solve as most of the times there seems to be no problem.
Even your observations with the scope may mislead you as connecting the
probe may change the circuit enough to change its behavior.

petrus bitbyter

== 2 of 9 ==
Date: Fri, Oct 21 2011 5:09 am
From: "Ian Field"

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:9gc2qeFlseU1@mid.individual.net...
>
> "Arfa Daily"
>> "Phil Allison"
>>> No, it's regulated DC.
>>>>>
>>>>>
>>>>> ** With just two transistors and one mosfet ?
>>>>>
>>>>> That is what you have told us.
>>>>>
>>>>> And SFA else.
>>>>
>>>>>
>>>> You shouldn't take things quite so literally, Phil. I was talking about
>>>> the primary side only when I said that, but yes, it pretty much has a
>>>> pair of small TO92 transistors, and a TO220 mosfet. Obviously, it also
>>>> has input filtering, a bridge, made of 4 discrete diodes, a main filter
>>>> cap, and assorted R and C to make those two little transistors into an
>>>> oscillator. About 20 components altogether. The secondary side is
>>>> exactly like any other fixed voltage typical design, and there is, of
>>>> course, a perfectly normal 6 pin opto for regulation feedback. Better ?
>>>
>>>
>>> ** All that needed to be in the first post, plus the operating
>>> frequency.
>>>
>>> Now it seems the whole story was BS anyhow.
>>>
>>
>> Well, actually, it didn't, as it was irrelevant to the situation.
>
>
> ** The one YOU alone knew about and WE did not !!!
>
> You fucking pommy retard.
>
>
>> How the mosfet receives its drive is neither here nor there
>
>
> ** Was NOT the issue - you bullshitting pommy turd.
>
> Whether the SMPS was a normal regulated, DC type WAS !!!
>
> With only 3 active devices mentioned, it seemed unlikely.
>
> You fucking pommy retard.
>
>
>> As long as it has a pulse width modulated 'square' wave of sufficient
>> amplitude to fully drive the gate, how that waveform is produced is of no
>> consequence.
>
> ** Your qualification above was also MISSING from the story - fuckhead.
>
>
>> As to the operating frequency, yes, I probably should have stated this,
>> but most supplies of this sort of size, operate between 40 kHz and 80
>> KHz, as would be understood by anyone who works with them regularly.
>
> ** FFS - you tenth witted MORON !!
>
> We are considering a FAULTY design scenario here.
>
> So NO such wild assumptions can be made - at all !!!
>
> My god you are STUPID !!!
>
>
>> And why do you think it's all bullshit ?
>
>
> ** Errr - you just told us you were wrong about the mosfet heating
> issue.
>
> You god almighty, pommy retard.
>
>
>
>
> ... Phil

Such eloquence.

== 3 of 9 ==
Date: Fri, Oct 21 2011 5:12 am
From: "Ian Field"

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:lr3oq.5208$UN2.1898@newsfe04.ams2...
>
>
> "Jim Yanik" <jyanik@abuse.gov> wrote in message
> news:Xns9F8477002E528jyaniklocalnetcom@216.168.3.44...
>> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in
>> news:JKKnq.3161$V_3.67@newsfe06.ams2:
>>
>>
>>
>>> You shouldn't take things quite so literally, Phil. I was talking
>>> about the primary side only when I said that, but yes, it pretty much
>>> has a pair of small TO92 transistors, and a TO220 mosfet. Obviously,
>>> it also has input filtering, a bridge, made of 4 discrete diodes, a
>>> main filter cap, and assorted R and C to make those two little
>>> transistors into an oscillator. About 20 components altogether. The
>>> secondary side is exactly like any other fixed voltage typical design,
>>> and there is, of course, a perfectly normal 6 pin opto for regulation
>>> feedback. Better ?
>>>
>>> Arfa
>>>
>>>
>>
>> I've been wondering about how the regulating feedback loop works.
>> How does it modify the multivibrator's output?
>>
>>
>> --
>> Jim Yanik
>
> Don't know, Jim. I don't have any schematics for it, as is ever the case,

Can't remember the last time I had a schematic for a PSU I was repairing, I
frequently trace them out by hand.

If its only an astable driving a MOSFET (or thereabouts) and you have a few
to fix, it shouldn't be too much of a hardship for the gain.

== 4 of 9 ==
Date: Fri, Oct 21 2011 5:18 am
From: "Ian Field"

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:MB3oq.5714$_p4.409@newsfe19.ams2...
> <snip>
>>
>>
>> Are the 330pF multilayer ceramic that could have metalisation creep /
>> cracks/ unreliable /leaky from humidity. I would replace them with a
>> different brand/construction
>>
>>
>
> It would probably be worth doing some further checks on those caps to make
> sure that they are not any part of the problem

The low capacitance, high voltage disc-ceramics sometimes used for flyback
tuning in TV LOPT stage have been known to fail, ut its usually visible.

Sometimes the ceramic disc cracks and is usually visible because the resin
dip also cracks with it, sometimes they track around the edge of the ceramic
disc and burn a little "volcano" through the coating.

== 5 of 9 ==
Date: Fri, Oct 21 2011 5:48 pm
From: "Arfa Daily"

"Ian Field" <gangprobing.alien@ntlworld.com> wrote in message
news:Chdoq.686$bI5.366@newsfe10.ams2...
>
> "Phil Allison" <phil_a@tpg.com.au> wrote in message
> news:9gc2qeFlseU1@mid.individual.net...
>>
>> "Arfa Daily"
>>> "Phil Allison"
>>>> No, it's regulated DC.
>>>>>>
>>>>>>
>>>>>> ** With just two transistors and one mosfet ?
>>>>>>
>>>>>> That is what you have told us.
>>>>>>
>>>>>> And SFA else.
>>>>>
>>>>>>
>>>>> You shouldn't take things quite so literally, Phil. I was talking
>>>>> about the primary side only when I said that, but yes, it pretty much
>>>>> has a pair of small TO92 transistors, and a TO220 mosfet. Obviously,
>>>>> it also has input filtering, a bridge, made of 4 discrete diodes, a
>>>>> main filter cap, and assorted R and C to make those two little
>>>>> transistors into an oscillator. About 20 components altogether. The
>>>>> secondary side is exactly like any other fixed voltage typical design,
>>>>> and there is, of course, a perfectly normal 6 pin opto for regulation
>>>>> feedback. Better ?
>>>>
>>>>
>>>> ** All that needed to be in the first post, plus the operating
>>>> frequency.
>>>>
>>>> Now it seems the whole story was BS anyhow.
>>>>
>>>
>>> Well, actually, it didn't, as it was irrelevant to the situation.
>>
>>
>> ** The one YOU alone knew about and WE did not !!!
>>
>> You fucking pommy retard.
>>
>>
>>> How the mosfet receives its drive is neither here nor there
>>
>>
>> ** Was NOT the issue - you bullshitting pommy turd.
>>
>> Whether the SMPS was a normal regulated, DC type WAS !!!
>>
>> With only 3 active devices mentioned, it seemed unlikely.
>>
>> You fucking pommy retard.
>>
>>
>>> As long as it has a pulse width modulated 'square' wave of sufficient
>>> amplitude to fully drive the gate, how that waveform is produced is of
>>> no consequence.
>>
>> ** Your qualification above was also MISSING from the story - fuckhead.
>>
>>
>>> As to the operating frequency, yes, I probably should have stated this,
>>> but most supplies of this sort of size, operate between 40 kHz and 80
>>> KHz, as would be understood by anyone who works with them regularly.
>>
>> ** FFS - you tenth witted MORON !!
>>
>> We are considering a FAULTY design scenario here.
>>
>> So NO such wild assumptions can be made - at all !!!
>>
>> My god you are STUPID !!!
>>
>>
>>> And why do you think it's all bullshit ?
>>
>>
>> ** Errr - you just told us you were wrong about the mosfet heating
>> issue.
>>
>> You god almighty, pommy retard.
>>
>>
>>
>>
>> ... Phil
>
>
> Such eloquence.
>

Indeed. I really don't know how the antipodean twat gets through life with
so little between his ears. Still, par for the course, I suppose. As I said,
just Philip spoiling for a fight, as ever ...

Arfa

== 6 of 9 ==
Date: Fri, Oct 21 2011 5:50 pm
From: "Arfa Daily"

"Ian Field" <gangprobing.alien@ntlworld.com> wrote in message
news:4ldoq.5595$gy7.2297@newsfe28.ams2...
>
> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
> news:lr3oq.5208$UN2.1898@newsfe04.ams2...
>>
>>
>> "Jim Yanik" <jyanik@abuse.gov> wrote in message
>> news:Xns9F8477002E528jyaniklocalnetcom@216.168.3.44...
>>> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in
>>> news:JKKnq.3161$V_3.67@newsfe06.ams2:
>>>
>>>
>>>
>>>> You shouldn't take things quite so literally, Phil. I was talking
>>>> about the primary side only when I said that, but yes, it pretty much
>>>> has a pair of small TO92 transistors, and a TO220 mosfet. Obviously,
>>>> it also has input filtering, a bridge, made of 4 discrete diodes, a
>>>> main filter cap, and assorted R and C to make those two little
>>>> transistors into an oscillator. About 20 components altogether. The
>>>> secondary side is exactly like any other fixed voltage typical design,
>>>> and there is, of course, a perfectly normal 6 pin opto for regulation
>>>> feedback. Better ?
>>>>
>>>> Arfa
>>>>
>>>>
>>>
>>> I've been wondering about how the regulating feedback loop works.
>>> How does it modify the multivibrator's output?
>>>
>>>
>>> --
>>> Jim Yanik
>>
>> Don't know, Jim. I don't have any schematics for it, as is ever the case,
>
>
> Can't remember the last time I had a schematic for a PSU I was repairing,
> I frequently trace them out by hand.
>
> If its only an astable driving a MOSFET (or thereabouts) and you have a
> few to fix, it shouldn't be too much of a hardship for the gain.

The company have now come back to me, and accepted the quotes that I have
given them for quantity repair on this supply, so it will now be worth
spending the time to trace it out.

Arfa

== 7 of 9 ==
Date: Fri, Oct 21 2011 5:54 pm
From: "Arfa Daily"

"Ian Field" <gangprobing.alien@ntlworld.com> wrote in message
news:sqdoq.860$gS1.157@newsfe17.ams2...
>
> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
> news:MB3oq.5714$_p4.409@newsfe19.ams2...
>> <snip>
>>>
>>>
>>> Are the 330pF multilayer ceramic that could have metalisation creep /
>>> cracks/ unreliable /leaky from humidity. I would replace them with a
>>> different brand/construction
>>>
>>>
>>
>> It would probably be worth doing some further checks on those caps to
>> make sure that they are not any part of the problem
>
> The low capacitance, high voltage disc-ceramics sometimes used for flyback
> tuning in TV LOPT stage have been known to fail, ut its usually visible.
>
> Sometimes the ceramic disc cracks and is usually visible because the resin
> dip also cracks with it, sometimes they track around the edge of the
> ceramic disc and burn a little "volcano" through the coating.
>

Yes, that's the type of cap that it is, and those modes of failure are my
experience of them also. These show no signs of anything like that, and
check ok for leakage - although not actually tested for this at high
voltage - and capacitance.

Arfa

== 8 of 9 ==
Date: Fri, Oct 21 2011 5:54 pm
From: "Phil Allison"

"Arfa Daily"

** Get utterly fucked

- you stupid, bullshitting, pommy TROLL

== 9 of 9 ==
Date: Fri, Oct 21 2011 6:03 pm
From: "Arfa Daily"

>>>
>>>
>
> Didn't you walk right into the problem? It seems that by a yet unknown
> cause the circuit sometimes runs into some state that makes it oscillate
> or in some other way fries the resistors. This kind of intermitted faults
> are the most difficult to solve as most of the times there seems to be no
> problem. Even your observations with the scope may mislead you as
> connecting the probe may change the circuit enough to change its behavior.
>
> petrus bitbyter
>

Yes, there may indeed be some kind of intermittent problem. I will put them
all back up again on Monday, and see how they perform this time. As to my
'scope muddying the waters, it's generally pretty well behaved in that
respect. It's a high quality 100 MHz job, which is always used with a x 10
low capacitance probe. If that is having much of an effect on the circuit,
then it must for sure be a pretty poor design. To be honest, I still think
that the problem lies with me somehow. Something that I did differently
between the first and second times that I tried them, but I'm not sure what
...

Arfa

==============================================================================
TOPIC: GE rant, and oven controll board problem
http://groups.google.com/group/sci.electronics.repair/t/2e46146acae5f251?hl=en
==============================================================================

== 1 of 5 ==
Date: Fri, Oct 21 2011 5:48 am
From: Franc Zabkar

On Thu, 20 Oct 2011 16:05:32 -0700 (PDT), George Herold
<ggherold@gmail.com> put finger to keyboard and composed:

>On Oct 20, 4:58 pm, Franc Zabkar <fzab...@iinternode.on.net> wrote:
>> On Thu, 20 Oct 2011 13:06:35 -0700 (PDT), George Herold
>> <gher...@teachspin.com> put finger to keyboard and composed:
>>
>> >We have a GE profile electric oven (made in 1993).
>>
>> A model number may help.
>>
>> A photo of the board would be nice, too.
>>
>> - Franc Zabkar
>> --
>> Please remove one 'i' from my address when replying by email.
>
>The model number of the control board is WB27K5107.

Sears have the board listed as "return for repair":
http://www.searspartsdirect.com/partsdirect/part-number/WB27K5107

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

== 2 of 5 ==
Date: Fri, Oct 21 2011 6:56 am
From: George Herold

On Oct 21, 8:48 am, Franc Zabkar <fzab...@iinternode.on.net> wrote:
> On Thu, 20 Oct 2011 16:05:32 -0700 (PDT), George Herold
> <ggher...@gmail.com> put finger to keyboard and composed:
>
> >On Oct 20, 4:58 pm, Franc Zabkar <fzab...@iinternode.on.net> wrote:
> >> On Thu, 20 Oct 2011 13:06:35 -0700 (PDT), George Herold
> >> <gher...@teachspin.com> put finger to keyboard and composed:
>
> >> >We have a GE profile electric oven (made in 1993).
>
> >> A model number may help.
>
> >> A photo of the board would be nice, too.
>
> >> - Franc Zabkar
> >> --
> >> Please remove one 'i' from my address when replying by email.
>
> >The model number of the control board is WB27K5107.
>
> Sears have the board listed as "return for repair":http://www.searspartsdirect.com/partsdirect/part-number/WB27K5107
>
> - Franc Zabkar
> --
> Please remove one 'i' from my address when replying by email.

Thanks Franc, I'm just going stick with the repair place I found.

George H

== 3 of 5 ==
Date: Fri, Oct 21 2011 10:15 am
From: John Robertson

George Herold wrote:
> On Oct 20, 4:24 pm, John Robertson <s...@flippers.com> wrote:
>> George Herold wrote:
>>> We have a GE profile electric oven (made in 1993). The oven stopped
>>> working. When you pushed the button to turn the oven on the display
>>> just blinked. A call to the local repair guy, "We don't service GE
>>> stuff, sorry". I wondered why at the time. So my wife called a GE
>>> repairman and scheduled a visit. The day before the visit he called
>>> to get the problem details. "Oh", he says, "You need a new oven
>>> control board and GE no longer makes it."
>>> So GE's idea is that I buy a new oven. I think I might rather have
>>> hot pokers in my eye's than buy a GE product!
>>> Anyway I'm sending my board off to Fixyourboard.com tomorrow, ($160
>>> and a two year guarantee). Now I've got the board sitting in front
>>> of me, if anyone here some idea of what to try I could save the money
>>> and time. There are no obvious blown bits on the board, and I removed
>>> and reinstalled the one connector cable.
>>> Thanks guys, And don't buy a GE product!
>>> George H.
>> Its almost twenty years old. That is not bad for electronic items to
>> finally need any service. Do you drive a 1993 car, use it daily, and
>> expect it to not need service?
>
> I've got a '95 Ford van that was just retired... still used to pull a
> boat to the lake. An '83 Datsun (now Nissian) pickup truck that gets
> work almost every weekend. (But almost always in 4WD low gear.) And
> my pride and joy, a '49 Ferguson tractor. 'course there's not to many
> IC's on that to fail. :^)
>
> And I can still get parts for all those vehicles.
>
> George H.

Yes, you can get car parts from after market suppliers or part
manufacturers for vehicles - hobbiests get into the act after more time
(look at Model T/A parts as an example - Ford has nothing to do with
these parts...) .

Stoves and other appliances are far more reliable than cars and as such
don't support much aftermarket supplies other than the folks you found
or companies like mine where we service obsolete amusement machines (but
not stoves or other home appliances).

John :-#)#

>> Manufacturers generally only stock parts for up to 5 years - after that
>> you are at the mercy of the aftermarket folks.
>
> Yup that's what I'm learning.
>> At least you found someone willing to fix it!
>>
>> John :-#)#
>>
>> --
>> (Please post followups or tech enquiries to the newsgroup)
>> John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
>> Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
>> www.flippers.com
>> "Old pinballers never die, they just flip out."- Hide quoted text -
>>
>> - Show quoted text -
>

--
(Please post followups or tech enquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

== 4 of 5 ==
Date: Fri, Oct 21 2011 3:24 pm
From: klem kedidelhopper

On Oct 21, 1:15 pm, John Robertson <s...@flippers.com> wrote:
> George Herold wrote:
> > On Oct 20, 4:24 pm, John Robertson <s...@flippers.com> wrote:
> >> George Herold wrote:
> >>> We have a GE profile electric oven (made in 1993). The oven stopped
> >>> working. When you pushed the button to turn the oven on the display
> >>> just blinked. A call to the local repair guy, "We don't service GE
> >>> stuff, sorry". I wondered why at the time. So my wife called a GE
> >>> repairman and scheduled a visit. The day before the visit he called
> >>> to get the problem details. "Oh", he says, "You need a new oven
> >>> control board and GE no longer makes it."
> >>> So GE's idea is that I buy a new oven. I think I might rather have
> >>> hot pokers in my eye's than buy a GE product!
> >>> Anyway I'm sending my board off to Fixyourboard.com tomorrow, ($160
> >>> and a two year guarantee). Now I've got the board sitting in front
> >>> of me, if anyone here some idea of what to try I could save the money
> >>> and time. There are no obvious blown bits on the board, and I removed
> >>> and reinstalled the one connector cable.
> >>> Thanks guys, And don't buy a GE product!
> >>> George H.
> >> Its almost twenty years old. That is not bad for electronic items to
> >> finally need any service. Do you drive a 1993 car, use it daily, and
> >> expect it to not need service?
>
> > I've got a '95 Ford van that was just retired... still used to pull a
> > boat to the lake. An '83 Datsun (now Nissian) pickup truck that gets
> > work almost every weekend. (But almost always in 4WD low gear.) And
> > my pride and joy, a '49 Ferguson tractor. 'course there's not to many
> > IC's on that to fail. :^)
>
> > And I can still get parts for all those vehicles.
>
> > George H.
>
> Yes, you can get car parts from after market suppliers or part
> manufacturers for vehicles - hobbiests get into the act after more time
> (look at Model T/A parts as an example - Ford has nothing to do with
> these parts...) .
>
> Stoves and other appliances are far more reliable than cars and as such
> don't support much aftermarket supplies other than the folks you found
> or companies like mine where we service obsolete amusement machines (but
> not stoves or other home appliances).
>
> John :-#)#
>
>
>
> >> Manufacturers generally only stock parts for up to 5 years - after that
> >> you are at the mercy of the aftermarket folks.
>
> > Yup that's what I'm learning.
> >> At least you found someone willing to fix it!
>
> >> John :-#)#
>
> >> --
> >> (Please post followups or tech enquiries to the newsgroup)
> >> John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
> >> Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
> >> www.flippers.com
> >> "Old pinballers never die, they just flip out."- Hide quoted text -
>
> >> - Show quoted text -
>
> --
> (Please post followups or tech enquiries to the newsgroup)
> John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
> Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
> www.flippers.com
> "Old pinballers never die, they just flip out."

I just had to jump in here because this is something very close to my
heart. We used to own a GE refrigerator. I bought this in 1981 at a
special discount when I was a GE employee. In 27 years we experienced
one problem with it. The drain tube from the freezer got plugged up ,
(with frozen crumbs from the freezer), and would not allow the water
to drain properly during the defrost cycles. This minor problem caused
a bit of a leak at times. It didn't really affect the operation of the
unit and we eventually fixed it, (sucked out the line with a turkey
baster) and that was fine. The water however caused a small rust
problem on the bottom of the box under the door. Personally I never
noticed it but my wife, who notices everything was really upset over
this.

Being in the consumer electronics service business I know how stuff is
made today and I was determined to hold on to my old faithful in spite
of the rust. However this became very important to her and when the
kids offered to buy us a new refrigerator for our 25 wedding
anniversary, well, what could I do? So we donated my old friend to the
Boy Scouts and got a new LG. The Lg lasted just three years.

The serviceman told us that he would have to replace the entire sealed
system and even with all that he still couldn't guarantee that he
could actually find the leak or that it wouldn't leak again. Do you
know how many times I've kicked myself in the ass for letting my old
GE go?

I never listen to salesmen because they usually just tell you what you
want to hear however an appliance salesman in Best Buy really put it
in perspective for me when I balked at buying a service contract for
my now, third refrigerator. You see I don't feel that we should have
to pay what amounts to a ransom for the privilege of having something
last more than three years. This guy was an appliance repairman years
before he was a salesman. He agreed with me but added, "you have to
realize that everything that's made today is CRAP. And so you need to
protect yourself when you buy something new".

I've known this for years and have been preaching it to my wife for 33
of them. She's never believed me, until now. We have held on to most
of our old stuff. Some of my TV's have manual tuners but they still
produce stunning pictures. Our GE coffee maker was a wedding present.
It was put in the basement every time we bought a new coffee maker and
brought back out every time one of the new pieces of crap shit the bed
and had to be tossed. This is now our last coffee maker. Now she
finally believes me. But sadly the GE refrigerator is gone and it's
not coming back. The answer is to not to cave in and buy new. "New" is
synonymous with "CRAP". Hold on to your old stuff and fix it as long
as you can. They just don't make em like that any more. Lenny

== 5 of 5 ==
Date: Fri, Oct 21 2011 8:56 pm
From: "hrhofmann@att.net"

On Oct 20, 3:06 pm, George Herold <gher...@teachspin.com> wrote:
> We have a GE profile electric oven (made in 1993). The oven stopped
> working. When you pushed the button to turn the oven on the display
> just blinked. A call to the local repair guy, "We don't service GE
> stuff, sorry". I wondered why at the time. So my wife called a GE
> repairman and scheduled a visit. The day before the visit he called
> to get the problem details. "Oh", he says, "You need a new oven
> control board and GE no longer makes it."
>
> So GE's idea is that I buy a new oven. I think I might rather have
> hot pokers in my eye's than buy a GE product!
>
> Anyway I'm sending my board off to Fixyourboard.com tomorrow, ($160
> and a two year guarantee). Now I've got the board sitting in front
> of me, if anyone here some idea of what to try I could save the money
> and time. There are no obvious blown bits on the board, and I removed
> and reinstalled the one connector cable.
>
> Thanks guys, And don't buy a GE product!
>
> George H.

It's almost 19 years old, what do you expect????

==============================================================================
TOPIC: NEW UPDATS
http://groups.google.com/group/sci.electronics.repair/t/a1efeaff713ca30b?hl=en
==============================================================================

== 1 of 1 ==
Date: Fri, Oct 21 2011 7:08 am
From: SRAVANTHI LOVE

FOR GOOD JOBS SITES TO YOU
http://goodjobssites.blogspot.com/

LATEST AMISHA PATEL HOT PICS
http://hotactress-kalyani.blogspot.com/2011/08/amisha-patel-hot.html
TAPSEE DIFFERENT STILLS
http://hotactress-kalyani.blogspot.com/2011/08/tapsee-hot.html
PRIYAMANI HOT PHOTOS
http://hotactress-kalyani.blogspot.com/2011/09/priyamani-hot.html

==============================================================================
TOPIC: Composite video from Compaq Armada e500.
http://groups.google.com/group/sci.electronics.repair/t/86cceb3718265fb1?hl=en
==============================================================================

== 1 of 1 ==
Date: Fri, Oct 21 2011 8:38 am
From: Peter Easthope

On Sep 14, 8:33 am, stratu...@yahoo.com wrote:
> Bottom line: if you displayed color bars on the Compaq the scope photo
> from Tek will be close to what you see on your scope once you get the
> sweep and gains set up. The trickiest part of TV is triggering the
> scope but many scopes have a TV mode to make it easier.

OK. The manual is with the B&K scope here. When there is a quiet
afternoon I'll work on it again.

Thanks! ... Peter E.

==============================================================================
TOPIC: White LED spectrum?
http://groups.google.com/group/sci.electronics.repair/t/7b379dacdacd2dfe?hl=en
==============================================================================

== 1 of 3 ==
Date: Sat, Oct 22 2011 12:13 am
From: DaveC

> "White" LEDs are actually blue LEDs with a phosphor that glows yellow under
> blue light. The eyes sees blue + yellow = white.
>
> Their spectrum is anything but continuous -- or even peaked at the right
> points -- so it's highly unlikely to work.

I appreciate your simple and obviously knowledgable answer. It will help me
in my search for the right decision.

Dave

== 2 of 3 ==
Date: Sat, Oct 22 2011 12:15 am
From: DaveC

> Most white LEDs are phosphor-based but hardy as bi-chromatic as you make
> them sound. The little Cree in my pocket flashlight has the typical
> broad peak around 450 nm and valley around 485 but it's quite continuous
> down to 650, tailing off at about 670. Very different from the narrow,
> discrete lines from a CCFL.
[Rich Webb]

Thanks, Rich.

I think the "striping" issue and potential variance between samples will make
for a less-than-satisfying result.

Thanks,
Dave

== 3 of 3 ==
Date: Sat, Oct 22 2011 12:17 am
From: DaveC

> I really have no help for the question asked, but I think people
> interested in the subject may have an answer to one of my questions.

And I have one word for you: HIJACK.

If you don't have an answer to the OP's question, fine. If you have a
question, START YOUR OWN THREAD.

==============================================================================

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