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

sci.electronics.repair@googlegroups.com

Today's topics:

* Debouncing Fails on My Remotes periodically! - 8 messages, 5 authors
http://groups.google.com/group/sci.electronics.repair/t/f79342b71e0d781b?hl=en
* another odd battery problem - 7 messages, 4 authors
http://groups.google.com/group/sci.electronics.repair/t/845e39030c509722?hl=en
* Ridiculous manufacturing technique - 6 messages, 4 authors
http://groups.google.com/group/sci.electronics.repair/t/251fb226aca41b21?hl=en
* Why would a DECT Panasonic cordless phone keep losing the wireless link? - 2
messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/cc34e585e15dfff5?hl=en
* Yamaha Stagepas 500W - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/ffe9b12e2d51ee46?hl=en
* TV/film scenario? - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/d7226526efadecfa?hl=en
* Unknown smd code? - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/9d003f6e76ce1b88?hl=en

==============================================================================
TOPIC: Debouncing Fails on My Remotes periodically!
http://groups.google.com/group/sci.electronics.repair/t/f79342b71e0d781b?hl=en
==============================================================================

== 1 of 8 ==
Date: Thurs, Jan 9 2014 4:58 pm
From: thekmanrocks@gmail.com


Kaz Kylheku wrote: "When you're holding down your remote's keys, you're sending multiple volume-up "

I must apologize for not being clear by "pressing harder". What I meant was I press the button with more FORCE, not for a longer duration.

Pressing the volume up/down once(the equivalent of a keystroke on a keybd) should adjust the volume by one value up or down.

I keep pressing it until my finger bone feels like it will either break or go through the back of the remote - THEN the volume races away like an NHRA hotrod - all the way up or down.

When I attempt to adjust the volume on the other remote, this phenomenon repeats.




== 2 of 8 ==
Date: Thurs, Jan 9 2014 5:22 pm
From: "William Sommerwerck"


I'm thinking... Maybe you just have dirty remote controls.




== 3 of 8 ==
Date: Thurs, Jan 9 2014 6:08 pm
From: jurb6006@gmail.com


Fuck. You ever work on TVs folks ? If I hemmed and hawed about it like this I would be making donuts.

You got a choice. Put a scope on the output of the IR sensor and wait days or weeks for the problem to occur, or replace the $1.50 sensor and see if it works. If the problem persists replace the micro if possible, or the main board.




== 4 of 8 ==
Date: Thurs, Jan 9 2014 6:21 pm
From: "Maynard A. Philbrook Jr."


In article <0411a3b7-287d-4ee8-8ec1-2a7bca6b4dfb@googlegroups.com>,
jurb6006@gmail.com says...
>
> Fuck. You ever work on TVs folks ? If I hemmed and hawed about it like this I would be making donuts.
>
> You got a choice. Put a scope on the output of the IR sensor and wait days or weeks for the problem to occur, or replace the $1.50 sensor and see if it works. If the problem persists replace the micro if possible, or the main board.

If the remote was really that important and maybe not replaceable, you
could put a CMOS version of a 555 timer on the output LED driver that
would have a timeOn delay and TimeOff delay to snub the output so that
only one frame gets sent.

Jamie





== 5 of 8 ==
Date: Thurs, Jan 9 2014 8:11 pm
From: jurb6006@gmail.com


OK, I don't know what is wrong here but let's just explore some logic here eh ?

Two, that is two (2) remotes, one OEM and one universal, are doing the same exact thing. One is OEM and one is universal therefore they are different chipsets and the odds against them having the exact same symptom, an INTEMITTENT symptom that occurs at the same time in both remotes, that have different chipsets, is astronomical.

We have gone though just about everything in the house. The CFLs, the sunlight, all that.

Oh shit.

Hey OP, you still around ? The last, very last test - when this happens again, BLOCK the IR sensor window and see if it stops. If it keeps going then it is for sure either the IR sensor or the micro in the TV. If you've already done that, disregard. We went through all the possible sources that you know about, but IR is not visible to the naked eye, so there is still a possibility.

Literally, stick your thumb over the window. That is the LAST definitive test.

IF it DOES stop with your thumb over the window, ummm, do you have an alarm system in the house ? Possibly with motion detectors ?

That is the ONLY other thing it could be other than the TV. Because the two DIFFERENT remotes act up at exactly the same time, they are RULED OUT AS A POSSIBLITY by LOGIC.

If you do not have motion detectors (even near a window from outside), if you are sure there is no source of IR hitting that thing, it is the detector or the micro. No doubt.

Now the sticky part, hahaha. you see I was always the one to do these wierd problems of course....

The reason you must stick your thumb over the window on the TV is because (now get this lol), your neighbor could have a motion detector light outside. The IR could be bouncing off of someting out there and into your window. Literally, it could be occurring when he parks his car just about a couple of cm. over to the right (or left) of normal, and you would NEVER know it. Remember you cannot see IR.

The odds of this are not great, it is quite unlikely, but it is possible. I have had shit like this. I have had vertical height screwing up the greyscale (because the worng dud was used in the reman of a CRT), I have had an unexplainable ground loop through a cable box that caused a hum bar in a projector because there were two ground rods installed at the house. I have had some pretty wierd problems and I know how to solve them. You have to consider the impossible sometimes.

This is your last test. Next you replace the IR sensor in the tv, and I give it a 50/50 chance. It could just as likely be the micro. If that's the case it is probably an SMD and is either difficult to replace or maybe near impossible, which would mean a new signal/main board.





== 6 of 8 ==
Date: Fri, Jan 10 2014 3:20 am
From: thekmanrocks@gmail.com


Jan 9jurb...@gmail.com wrote:

"OK, I don't know what is wrong here but let's just explore some logic here eh ?

Two, that is two (2) remotes, one OEM and one universal, are doing the same exact thing. One is OEM and one is universal therefore they are different chipsets and the odds against them having the exact same symptom, an INTEMITTENT symptom that occurs at the same time in both remotes, that have different chipsets, is astronomical.

We have gone though just about everything in the house. The CFLs, the sunlight, all that.

Oh shit.

Hey OP, you still around ? The last, very last test - when this happens again, BLOCK the IR sensor window and see if it stops. If it keeps going then it is for sure either the IR sensor or the micro in the TV. If you've already done that, disregard. We went through all the possible sources that you know about, but IR is not visible to the naked eye, so there is still a possibility.

Literally, stick your thumb over the window. That is the LAST definitive test.

IF it DOES stop with your thumb over the window, ummm, do you have an alarm system in the house ? Possibly with motion detectors ?

That is the ONLY other thing it could be other than the TV. Because the two DIFFERENT remotes act up at exactly the same time, they are RULED OUT AS A POSSIBLITY by LOGIC.

If you do not have motion detectors (even near a window from outside), if you are sure there is no source of IR hitting that thing, it is the detector or the micro. No doubt.

Now the sticky part, hahaha. you see I was always the one to do these wierd problems of course....

The reason you must stick your thumb over the window on the TV is because (now get this lol), your neighbor could have a motion detector light outside. The IR could be bouncing off of someting out there and into your window. Literally, it could be occurring when he parks his car just about a couple of cm. over to the right (or left) of normal, and you would NEVER know it. Remember you cannot see IR.

The odds of this are not great, it is quite unlikely, but it is possible. I have had shit like this. I have had vertical height screwing up the greyscale (because the worng dud was used in the reman of a CRT), I have had an unexplainable ground loop through a cable box that caused a hum bar in a projector because there were two ground rods installed at the house. I have had some pretty wierd problems and I know how to solve them. You have to consider the impossible sometimes.

This is your last test. Next you replace the IR sensor in the tv, and I give it a 50/50 chance. It could just as likely be the micro. If that's the case it is probably an SMD and is either difficult to replace or maybe near impossible, which would mean a new signal/main board. "

Both remotes are OEM - One for the TV and the other, the JVC vhs/dvd combo.

I get it. Next time I get a runaway volume, I will block the transmitter eyes of each remote. If runaway vol. stops, it's the remotes. If it does not, it's likely the Sanyo tv.

BTW: I have next to ZERO soldering skills, and I don't want to mess with a TV that so far has given excellent service overall. If it occurrs once every two weeks to every two months, I can live with that.




== 7 of 8 ==
Date: Fri, Jan 10 2014 9:14 am
From: jurb6006@gmail.com


NO NO NO ! Block the window on the TV ! We have already eliminated the remote transmitters.




== 8 of 8 ==
Date: Fri, Jan 10 2014 10:43 am
From: Allodoxaphobia


On Fri, 10 Jan 2014 09:14:49 -0800 (PST), jurb6006@gmail.com wrote:
>
> NO NO NO !
>Block the window on the TV ! We have already eliminated the remote
>transmitters.

AND, use a newsreader (OP) that quotes previous content correctly!

And, set your newsreader ("jurb") to wrap text around column 72.





==============================================================================
TOPIC: another odd battery problem
http://groups.google.com/group/sci.electronics.repair/t/845e39030c509722?hl=en
==============================================================================

== 1 of 7 ==
Date: Thurs, Jan 9 2014 7:28 pm
From: "Phil Allison"



"William Sommerwanker "
>
> When I put the third battery on charge again, it rose to about 7.5V, even
> before charge was terminated. I let it sit overnight, and it
> self-discharged (?) to about 5.5V. (The others //did not// show
> significant self-discharge.) It still wouldn't power the unit.
>
> "Obviously" this battery pack is defective. I'm just wondering if anyone
> knows what's going on.


** You are describing the standard "old age" failure mode of most NiCds.

1. The internal resistance of some or all the cells in a pack rises - often
dramatically.

2. The energy capacity drops by a large factor.

3. The pack will not hold charge due to internal leakage.

4. The terminal voltage is depressed, from 1.25V to about 1.2V per cell.

A single overheating event can result in the same outcome - whether by
overcharging or otherwise.

Reason ?

NiCd cells have a small amount of water in them - lose that and the cell is
stuffed.



... Phil









== 2 of 7 ==
Date: Thurs, Jan 9 2014 7:36 pm
From: "Phil Allison"



"Phil Allison"


> 4. The terminal voltage is depressed, from 1.25V to about 1.1V per cell.


... Phil






== 3 of 7 ==
Date: Thurs, Jan 9 2014 8:45 pm
From: mike


On 1/9/2014 4:47 PM, William Sommerwerck wrote:
> "Dave M" wrote in message
> news:7-GdnRWXTpL1fVPPnZ2dnUVZ_oOdnZ2d@giganews.com...
>
>> Nicads have historically been plagued by "dendrites", or crystals of
>> conductive material (probably cadmium, but not sure) between the
>> electrolyte layers in the cells. This creates a low resistance leakage
>> path inside the cells, rendering them incapable of retaining a charge
>> for any length of time or putting out their rated voltage. Dendrites are
>> responsible for the so-called "memory effect" that nicads are famous for.
>
>> There have been several procedures published on the net as to how to
>> remove dendrites (search for "nicad dendrites"). One process involves
>> charging a large electrolytic capacitor (eg, 500uF) to a few hundred
>> volts, discharging it through the bad cell, then running the cell
>> through a couple of charge/discharge cycles.
>
> I assume the discharge is + to +.
>
I'd be careful. Energy is proportional to the square of the voltage.
I use 12,000 uF and 10-20V, mostly because that's what was handy.
You want to hit the sweet spot where you instantly vaporize the dendrite,
but generate no more heat than necessary. Too little energy or too
much energy is worse than just right. That's why suggestions to
use a car battery are bad. Little chance of getting it just right.
Way too much chance of getting enough energy to explode something.

500uF AND 200V is WAY too much.

The process leaves the hole in the insulator/separator.
The field density is high and the dendrite wants to grow back.
And discharge thru the hole causes the high self-discharge rate.

I've had a lot of success restoring 40 year old F-NiCd's for
uses that don't require more than a few days storage life.
But, these days, you can get equivalent capacity in a pair of
AA NiMH cells.

Don't discount the safety issues with high voltage.
The "experts" who look at only part of the problem will call me an idiot,
because 200V probably won't kill you.
Two problems with that..."probably" is great for statistics, but
provides little solace to your family when you're the ONE who died.
And B, the shock isn't the only problem.
I've got scars where the muscle contractions that thru me across the
room caused me to rip my arm open on some sharp object in the path.
Luckily, I haven't fallen and cracked my head open on the furniture...
yet...

Eye Protection is a MUST. Sparks fly.
>
>> I built a little box for this process several years ago, and it seems
>> to work.
>> It consists of a transformer, a voltage doubler, and a large capacitor.
>> A push-button switch triggers an SCR that lets the capacitor discharge
>> into
>> the bad cell (sort of like a one-shot CD ignition).
>
>
> I'll give this serious thought. The worst that can happen is that the
> battery is ruined. (!!!) Thanks.
>
> I'm still curious about the battery's unnaturally high voltage.





== 4 of 7 ==
Date: Fri, Jan 10 2014 12:42 am
From: "William Sommerwerck"


Fine. Nothing new. But why the high voltage?




== 5 of 7 ==
Date: Fri, Jan 10 2014 1:39 am
From: "Phil Allison"



"William Sommerwanker the Over Snipper form HELL "

> Fine. Nothing new.


** All new to YOU fuckhead.

> But why the high voltage?


** When on charge - point 1 applies.

Cease charge the pack and the voltage drops almost immediately.

V = I x R ..........

Wot an idiot.



.... Phil








== 6 of 7 ==
Date: Fri, Jan 10 2014 4:04 am
From: "Dave M"


William Sommerwerck wrote:
> "Dave M" wrote in message
> news:7-GdnRWXTpL1fVPPnZ2dnUVZ_oOdnZ2d@giganews.com...
>
>
>> There have been several procedures published on the net as to how to
>> remove dendrites (search for "nicad dendrites"). One process involves
>> charging a large electrolytic capacitor (eg, 500uF) to a few hundred
>> volts, discharging it through the bad cell, then running the cell
>> through a couple of charge/discharge cycles.
>
> I assume the discharge is + to +.
>
>
>> I built a little box for this process several years ago, and it
>> seems to work.
>> It consists of a transformer, a voltage doubler, and a large
>> capacitor. A push-button switch triggers an SCR that lets the capacitor
>> discharge into the bad cell (sort of like a one-shot CD ignition).
>
>
> I'll give this serious thought. The worst that can happen is that the
> battery is ruined. (!!!) Thanks.


Yes, + to + on the CD pulse and normal charge/discharge.

Dave M






== 7 of 7 ==
Date: Fri, Jan 10 2014 6:40 am
From: "William Sommerwerck"


"Phil Allison" wrote in message news:bj9tfjFag1fU1@mid.individual.net...

> Fine. Nothing new.

** All new to YOU, fuckhead.

I've killed men for less than that.

I wasn't expecting you to repeat common knowledge about rechargeable
batteries.


> But why the high voltage?

** When on charge - point 1 applies.
** Cease charge the pack and the voltage drops almost immediately.
** V = I x R ..........
** Wot an idiot.

You don't see it, do you? Of course not.

The same thought crossed my mind. The question is... why should a cell's
voltage -- which is supposedly determined by the battery's chemistry --
essentially double (assuming only one cell is bad)? Why should the cell become
a sort of electrochemical chameleon, trying to match the voltage across it?






==============================================================================
TOPIC: Ridiculous manufacturing technique
http://groups.google.com/group/sci.electronics.repair/t/251fb226aca41b21?hl=en
==============================================================================

== 1 of 6 ==
Date: Fri, Jan 10 2014 6:36 am
From: "Gareth Magennis"


Blimey, I have just had one of these in for repair:

http://www.native-instruments.com/en/products/traktor/dj-controllers/traktor-kontrol-s4/


All the pots and data encoders are soldered to the PCB's as usual, and are
then fixed by the usual hex nuts to the top of the chassis.
BUT, the various top surface metal and plastic plates with all the legends
on are then GLUED over all these nuts.

The only way to remove the PCB's is to remove all these top plates, which
you can't do without severely damaging them as the glue bond is so strong.

These are obviously not designed to be repaired or serviced, unless you want
to buy a complete new set of top decal plates, which you almost certainly
can't cos these will be made in china and spares aren't available etc etc.

And these are not cheap either.


Cuh.






== 2 of 6 ==
Date: Fri, Jan 10 2014 7:35 am
From: N_Cook


On 10/01/2014 14:36, Gareth Magennis wrote:
> Blimey, I have just had one of these in for repair:
>
> http://www.native-instruments.com/en/products/traktor/dj-controllers/traktor-kontrol-s4/
>
>
> All the pots and data encoders are soldered to the PCB's as usual, and are
> then fixed by the usual hex nuts to the top of the chassis.
> BUT, the various top surface metal and plastic plates with all the legends
> on are then GLUED over all these nuts.
>
> The only way to remove the PCB's is to remove all these top plates, which
> you can't do without severely damaging them as the glue bond is so strong.
>
> These are obviously not designed to be repaired or serviced, unless you want
> to buy a complete new set of top decal plates, which you almost certainly
> can't cos these will be made in china and spares aren't available etc etc.
>
> And these are not cheap either.
>
>
> Cuh.
>
>

does warming with hot air gun weaken the glue bond?




== 3 of 6 ==
Date: Fri, Jan 10 2014 8:19 am
From: "Gareth Magennis"



"N_Cook" <diverse@tcp.co.uk> wrote in message
news:lap3vf$cgv$1@dont-email.me...
> On 10/01/2014 14:36, Gareth Magennis wrote:
>> Blimey, I have just had one of these in for repair:
>>
>> http://www.native-instruments.com/en/products/traktor/dj-controllers/traktor-kontrol-s4/
>>
>>
>> All the pots and data encoders are soldered to the PCB's as usual, and
>> are
>> then fixed by the usual hex nuts to the top of the chassis.
>> BUT, the various top surface metal and plastic plates with all the
>> legends
>> on are then GLUED over all these nuts.
>>
>> The only way to remove the PCB's is to remove all these top plates, which
>> you can't do without severely damaging them as the glue bond is so
>> strong.
>>
>> These are obviously not designed to be repaired or serviced, unless you
>> want
>> to buy a complete new set of top decal plates, which you almost certainly
>> can't cos these will be made in china and spares aren't available etc
>> etc.
>>
>> And these are not cheap either.
>>
>>
>> Cuh.
>>
>>
>
> does warming with hot air gun weaken the glue bond?


I was going to attempt that but I specifically needed to heat the area
around the 7 segment LED display which has a very thin transparent cover.

This unit is old now, and has had beer spilt in it, there is lots wrong with
it, I don't think I will be able to obtain spare parts for it, so I
abandoned the whole thing as uneconomic to repair.

The owner is going to attempt to send it back to the manufacturers.
Good luck there, mate.



Gareth.






== 4 of 6 ==
Date: Fri, Jan 10 2014 9:58 am
From: Cydrome Leader


N_Cook <diverse@tcp.co.uk> wrote:
> On 10/01/2014 14:36, Gareth Magennis wrote:
>> Blimey, I have just had one of these in for repair:
>>
>> http://www.native-instruments.com/en/products/traktor/dj-controllers/traktor-kontrol-s4/
>>
>>
>> All the pots and data encoders are soldered to the PCB's as usual, and are
>> then fixed by the usual hex nuts to the top of the chassis.
>> BUT, the various top surface metal and plastic plates with all the legends
>> on are then GLUED over all these nuts.
>>
>> The only way to remove the PCB's is to remove all these top plates, which
>> you can't do without severely damaging them as the glue bond is so strong.
>>
>> These are obviously not designed to be repaired or serviced, unless you want
>> to buy a complete new set of top decal plates, which you almost certainly
>> can't cos these will be made in china and spares aren't available etc etc.
>>
>> And these are not cheap either.
>>
>>
>> Cuh.
>>
>>
>
> does warming with hot air gun weaken the glue bond?

sometimes drops of isopropyl alcohol will soften that weird fiber/glue
stuff they use to hold decal down with.

still seems like a shity design, most likely just to be cheap than
anything else.

The entire of consumables for simply opening something up has always
annoyed me. At least with stuff like laptops real makers do offer the
replacement screws and screw cover kits which come with replacement parts
that require their removal.

Ending the use of lead-soft flat headed screws that will cam out after any
use would still be better.







== 5 of 6 ==
Date: Fri, Jan 10 2014 11:26 am
From: N_Cook


On 10/01/2014 16:19, Gareth Magennis wrote:
> "N_Cook" <diverse@tcp.co.uk> wrote in message
> news:lap3vf$cgv$1@dont-email.me...
>> On 10/01/2014 14:36, Gareth Magennis wrote:
>>> Blimey, I have just had one of these in for repair:
>>>
>>> http://www.native-instruments.com/en/products/traktor/dj-controllers/traktor-kontrol-s4/
>>>
>>>
>>> All the pots and data encoders are soldered to the PCB's as usual, and
>>> are
>>> then fixed by the usual hex nuts to the top of the chassis.
>>> BUT, the various top surface metal and plastic plates with all the
>>> legends
>>> on are then GLUED over all these nuts.
>>>
>>> The only way to remove the PCB's is to remove all these top plates, which
>>> you can't do without severely damaging them as the glue bond is so
>>> strong.
>>>
>>> These are obviously not designed to be repaired or serviced, unless you
>>> want
>>> to buy a complete new set of top decal plates, which you almost certainly
>>> can't cos these will be made in china and spares aren't available etc
>>> etc.
>>>
>>> And these are not cheap either.
>>>
>>>
>>> Cuh.
>>>
>>>
>>
>> does warming with hot air gun weaken the glue bond?
>
>
> I was going to attempt that but I specifically needed to heat the area
> around the 7 segment LED display which has a very thin transparent cover.
>
> This unit is old now, and has had beer spilt in it, there is lots wrong with
> it, I don't think I will be able to obtain spare parts for it, so I
> abandoned the whole thing as uneconomic to repair.
>
> The owner is going to attempt to send it back to the manufacturers.
> Good luck there, mate.
>
>
>
> Gareth.
>
>

for next time , just mask off the display area or even pre-chill with
freezer spray




== 6 of 6 ==
Date: Fri, Jan 10 2014 11:29 am
From: "Gareth Magennis"




"Cydrome Leader" wrote in message news:lapccv$1et$2@reader1.panix.com...

N_Cook <diverse@tcp.co.uk> wrote:
> On 10/01/2014 14:36, Gareth Magennis wrote:
>> Blimey, I have just had one of these in for repair:
>>
>> http://www.native-instruments.com/en/products/traktor/dj-controllers/traktor-kontrol-s4/
>>
>>
>> All the pots and data encoders are soldered to the PCB's as usual, and
>> are
>> then fixed by the usual hex nuts to the top of the chassis.
>> BUT, the various top surface metal and plastic plates with all the
>> legends
>> on are then GLUED over all these nuts.
>>
>> The only way to remove the PCB's is to remove all these top plates, which
>> you can't do without severely damaging them as the glue bond is so
>> strong.
>>
>> These are obviously not designed to be repaired or serviced, unless you
>> want
>> to buy a complete new set of top decal plates, which you almost certainly
>> can't cos these will be made in china and spares aren't available etc
>> etc.
>>
>> And these are not cheap either.
>>
>>
>> Cuh.
>>
>>
>
> does warming with hot air gun weaken the glue bond?

sometimes drops of isopropyl alcohol will soften that weird fiber/glue
stuff they use to hold decal down with.




I did take one small metal panel off just to confirm there were nuts
underneath.
It got a little mangled, and it looks like the "glue" is sheets of double
sided (very strong) adhesive medium covering the entire panel area.

I could probably have got it off unscathed with a hot air gun, but the more
delicate plastic panels might be a different story.

If it hadn't been full of beer and needing at least a couple of unobtanium
faders I might have thought it worth persevering.
As it was it just got my goat on a friday afternoon, and I fancied a good
vent on usenet!



Cheers,


Gareth.






==============================================================================
TOPIC: Why would a DECT Panasonic cordless phone keep losing the wireless link?

http://groups.google.com/group/sci.electronics.repair/t/cc34e585e15dfff5?hl=en
==============================================================================

== 1 of 2 ==
Date: Fri, Jan 10 2014 7:22 am
From: Danny D'Amico


On Wed, 08 Jan 2014 10:26:04 -0800, Jeff Liebermann wrote:

> Ummm... was the phone designed to use NiMH or NiCd batteries? I'm too
> lazy to check.

Hi Jeff,
The batteries are the original, and, they're all Ni-MH batteries.
I noticed a set (white paint) was of a different amperage, so,
I reassembled all the sets with like-amperage batteries (to
prevent reverse voltage situations).


> NiMH batteries can be a problem due to high self discharge and
> possible overcharging. I suggest that you charge a few of the
> batteries in the phones for a day and then remove the batteries.
> Measure the voltage which should be about 1.2V when fully charged.
> Just let them sit outside the handset for at least 12 hrs (or more).
> Then measure the voltage again. 1.1V to 1.2V is fairly normal. 1.0V
> is borderline.

I ran that from yesterday, Jeff, and they came back at 1.2 volts.
So, I must tentatively conclude that the phone itself has a
summative charging icon, where it might be "timed" in the charger,
rather than checked at the battery.

All five handsets, with the same batteries that read nearly dead
after charging, now read full. I haven't extensively tested yet,
but, all seems well now (tentative assessment).

> With 5 (US) channels to use, you're chances are 1 in 5 of having
> a collision. Unplug one base and see if the probleem goes away.

This might be the reason for the intermittence!

What I *should* do is buy a DECT system with 9 handsets instead
of two DECT systems for a total of 9 handsets.





== 2 of 2 ==
Date: Fri, Jan 10 2014 9:17 am
From: Jeff Liebermann


On Fri, 10 Jan 2014 15:22:06 +0000 (UTC), Danny D'Amico
<danny@is.invalid> wrote:

>On Wed, 08 Jan 2014 10:26:04 -0800, Jeff Liebermann wrote:
>
>> Ummm... was the phone designed to use NiMH or NiCd batteries? I'm too
>> lazy to check.
>
>Hi Jeff,
>The batteries are the original, and, they're all Ni-MH batteries.
>I noticed a set (white paint) was of a different amperage, so,
>I reassembled all the sets with like-amperage batteries (to
>prevent reverse voltage situations).

I don't believe it. The phones look at least 8 years old. If the
NiMH batteries were that old and left on continuous charge, they
should be nearly dead by now. I have a discharge tester (West Mtn
Radio CBA-II) that can test them. Send me one cell and I'll run a
test (time permitting).

>> NiMH batteries can be a problem due to high self discharge and
>> possible overcharging. I suggest that you charge a few of the
>> batteries in the phones for a day and then remove the batteries.
>> Measure the voltage which should be about 1.2V when fully charged.
>> Just let them sit outside the handset for at least 12 hrs (or more).
>> Then measure the voltage again. 1.1V to 1.2V is fairly normal. 1.0V
>> is borderline.
>
>I ran that from yesterday, Jeff, and they came back at 1.2 volts.

Ok, the batteries are not totally dead.

>So, I must tentatively conclude that the phone itself has a
>summative charging icon, where it might be "timed" in the charger,
>rather than checked at the battery.

Dunno. I've used a few Panasonic handsets around the house. The one
with individual cells ate batteries about every 3-5 years.

>All five handsets, with the same batteries that read nearly dead
>after charging, now read full. I haven't extensively tested yet,
>but, all seems well now (tentative assessment).

Offhand, I would say a bad battery or charger connection. The chrome
plated connections on both the handset and charger base don't make a
reliable connection and must be cleaned carefully. Same with the
internal battery contacts.

>> With 5 (US) channels to use, you're chances are 1 in 5 of having
>> a collision. Unplug one base and see if the probleem goes away.
>
>This might be the reason for the intermittence!
>
>What I *should* do is buy a DECT system with 9 handsets instead
>of two DECT systems for a total of 9 handsets.

Just buying some additional handsets for your existing base might
be a better and cheaper idea. The data sheets list the maximum number
of handsets a base will accomodate. I know of one system with 12
handsets. This might help:
<http://cordless-phones-review.toptenreviews.com/>
Oops. Looks like Panasonic is limited to 6 handsets.


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





==============================================================================
TOPIC: Yamaha Stagepas 500W
http://groups.google.com/group/sci.electronics.repair/t/ffe9b12e2d51ee46?hl=en
==============================================================================

== 1 of 1 ==
Date: Fri, Jan 10 2014 7:28 am
From: N_Cook


Just in case someone out there other than myself dares to take on these,
and any ideas. All the previous times as far as the PAs are concerned
just matter of replacing SMD fusible resitors and powerFETs. This time
done that but unit goes into protect mode. With known good PA only or no
PA in there, then no flashing green power LED = protect mode.
I bench test these little 2 ounce, 250W, "digital" PAs as far as
quiesence is concerned and with +/-30V supply rails , sits there happily
with normal , for this minimal test, 0.7mA balanced current draw.
Cold testing DVM-D fashion has shown up no difference to the known good
PA SMDs.
I suspect something in the protect monitoring part of the pa has gone
wrong at the original failure but its a workup to make extenders etc to
probe these amps in full live circuit. At least the schematics etc are
out there for these amps.





==============================================================================
TOPIC: TV/film scenario?
http://groups.google.com/group/sci.electronics.repair/t/d7226526efadecfa?hl=en
==============================================================================

== 1 of 1 ==
Date: Fri, Jan 10 2014 10:05 am
From: Cydrome Leader


William Sommerwerck <grizzledgeezer@comcast.net> wrote:
> "RobertMacy" wrote in message news:op.w9bv6mas2cx0wh@ajm...
>
>> However, the breaker may, or may not, have gone off.
>> Depends on the kind of breaker.
>
> About 15 years ago, a fire marshal (not Jim Carrey) warned me about the
> thermal breakers common in outlet strips. He said they often have a high
> resistance, and under heavy loads (though not higher than those the strip was
> rated for) could overheat and start a fire.

they sure do.

I've seen multiple fires (limited to the power strip) caused by these
pieces of junk.

Just came across a mini air compressor with a ~1HP motor (which of course
said 4HP on the label) that kept cutting out. Resistance of the 17A push
to reset breaker was almost 2 ohms, after being reset.

Not too surprisingly the thing would buzz loudly, never start, then trip.
Somebody else replaced the breaker and it still won't start, but it
doesn't trip now.





==============================================================================
TOPIC: Unknown smd code?
http://groups.google.com/group/sci.electronics.repair/t/9d003f6e76ce1b88?hl=en
==============================================================================

== 1 of 1 ==
Date: Fri, Jan 10 2014 11:31 am
From: N_Cook


On 09/01/2014 22:57, nalog.gugla@gmail.com wrote:
> Anyone please-got burned components but cannot find in any available catalogs nor google what they are:
> sot89(4pin) and marking code '1F'(possibly same as the one marked '322018')
> sc59(3p) and '2127'
> thanks in advance
>

Try googling, an idea of its function may narrow down a bit

"1F" AND "filetype:pdf" "top code" OR "topcode" OR "top mark" OR
"topmark" OR "marking" OR "code"




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