Digest for sci.electronics.repair@googlegroups.com - 19 updates in 4 topics

"pfjw@aol.com" <peterwieck33@gmail.com>: Mar 14 01:04PM -0700


> GFCIs are far from failsafe. Well worth having but not entirely reliable by any means, and not failsafe.
 
Nothing is fail-safe other than a low-voltage, battery-operated system. Anything that includes a primary source whether isolated or not, whether on a GFCI device, or not - there could be a way for primary power to migrate to the secondary side and/or jump the GFCI device. One may reduce the odds of failure via redundancy, or by other means. Or, one may take ordinary common-sense precautions in the full understanding that nothing is perfect.
 
Kinda-sorta like spending one's life living under a rock, or taking the ordinary risks of daily life and enjoy what life one is allotted under such terrible threats.
 
Peter Wieck
Melrose Park, PA
tabbypurr@gmail.com: Mar 14 01:50PM -0700


> Kinda-sorta like spending one's life living under a rock, or taking the ordinary risks of daily life and enjoy what life one is allotted under such terrible threats.
 
> Peter Wieck
> Melrose Park, PA
 
That doesn't really tell us anything does it. Let me put it another way: RCD failures are no rarity. They're nowhere near failsafe. And of course they don't act on all shock/electrocution scenarios anyway.
 
 
NT
jurb6006@gmail.com: Mar 14 05:16PM -0700

>"Nothing is fail-safe other than a low-voltage, battery-operated system."
 
Almost, such a system could develop line leakage like any other. Then it is dependent on the GFCI.
Terry Schwartz <tschw10117@aol.com>: Mar 14 05:25PM -0700

> >"Nothing is fail-safe other than a low-voltage, battery-operated system."
 
> Almost, such a system could develop line leakage like any other. Then it is dependent on the GFCI.
 
A low voltage, battery-operated system can develop line leakage? How is that? And exactly where in a battery system would one use a GFCI?
jurb6006@gmail.com: Mar 15 04:24AM -0700

>"How is that?"
 
The charger.
 
Unless you mean solar, that is different.
 
Know what ? I think it would be adequate just to use a GFCI breaker AND a GFCI outlet and be done with it.
 
But seriously, did you mean that they disconnect the charger when the lights are in use ? If you meant that or solar then I was wrong.
Terry Schwartz <tschw10117@aol.com>: Mar 15 09:33AM -0700

I envisioned an LED system with a healthy sized gel battery.... charging would take place when the system is disconnected. With the right battery you could probably run such a light string all summer and only need to charge it a few times. With a solar array, never.
 
Leaving a charger connected would defeat the purpose. And some chargers will only charge until the voltage level is met, and not restart unless disconnected anyway. A battery maintainer or tender would likely be smart enough to charge when the voltage drops. But it's a moot point.
 
One thing I can say with certainty here is that the 120V string of lights above the pool MUST GO!
Mike_Duffy <mqduffy001@bell.net>: Mar 14 02:56PM -0400

On Wed, 14 Mar 2018 09:36:14 -0700 (PDT), Terry Schwartz wrote:
 
 
> A large percentage of claims are just like yours,
> where the coverage is contested and the goodwill
> is taken care of by the OEM.
 
They were not very explicit, and I was subject to the minor language
barrier of speaking to them in Quebec French.
 
Everything you say is consistent with what was related to me, except why
would they imply at first that I would have to pay for the repair if they
already had prior approval from Ford to cover it under warranty?
 
I balked at first when his computer told him that the $800+ repair was not
covered by warranty, and waited until he had cleared up the matter with the
service manager.
Terry Schwartz <tschw10117@aol.com>: Mar 14 12:51PM -0700

Well the dealer makes more money/hour on out of warranty service than in warranty service, so that is the probable reason they would rather you paid than the OEM. Also it takes some time to contact the OEM and get approval, and you were there waiting. Their initial quote was pre-contact.
tabbypurr@gmail.com: Mar 14 01:51PM -0700

On Wednesday, 14 March 2018 18:56:28 UTC, Mike_Duffy wrote:
 
> Everything you say is consistent with what was related to me, except why
> would they imply at first that I would have to pay for the repair if they
> already had prior approval from Ford to cover it under warranty?
 
they wanted your money by any chance?
 
Mike_Duffy <mqduffy001@bell.net>: Mar 14 06:28PM -0400

On Wed, 14 Mar 2018 12:51:43 -0700 (PDT), Terry Schwartz wrote:
 
> Their initial quote was pre-contact.
 
Maybe thay alwys say "It's probably not covered" before they check. It's
not really lying, but it's not really honest. I seem to recall that they
did not, in fact have the time do the repairs that day. They were trying to
set up an appointment to do the reair.
jurb6006@gmail.com: Mar 14 05:04PM -0700

>"And yesterday, the engine 'indicator' came on. I made a garage appointment for this afternoon, during which I expect to spend time & money."
 
You know many auto parts stores, at least around here, will run the codes for you. One time they ran them and it was rear O2 sensor slow to respond and they suggested cleaning it. I did and it worked, never a problem after that.
 
>"The last
time the light came on was a major repair (cheap part, but lots of labour)to something deep inside the engine that adjusted valve timing based on load, etc. "
 
So you have variable valve timing. Yup, a bit expensive to implement but is really great for performance. I experimented with it before Porsche even came out with it I think. I had this Pinto and found when I timed it one way it had oodles of low end torque, I mean you could slip your foot off the clutch at idle and it would go. However, no matter what gear it was in it would only do about 45 MPH.
 
Timed the other way is seemed like a gutless wonder and feather the clutch or it would stall. However when it hit a certain RPM it really started to move. I mean really move. It went faster in first gear than ever before. Luckily I did not blow the engine.
 
I was lucky the way the (BMW built) engine was, the cam gear was at the top and the tensioner was easy to get to without removing anything as I had left the cover off for this purpose, being the experimenter I was. I was able to change the vale timing in a minute without disturbing anything else, even the ignition timing.
 
>"Apparently, the garage paid the bill, not Ford. "
 
Good, everything is expensive now. And as far as I am concerned it is part of the engine, I would have considered a suit or mediation with a consumer affairs arbiter. To claim otherwise would be like saying speakers are not part of a stereo.
jurb6006@gmail.com: Mar 14 05:06PM -0700

On Wednesday, March 14, 2018 at 11:27:16 AM UTC-5, Terry Schwartz wrote:
> No. Those gauges are certainly stepper motors. You're seeing them find "home". There is no position feedback, so there has to be a regular process of resetting the pointers.
 
Not in my experience but I stopped working on cars quite a while ago. So I will take your word for it.
jurb6006@gmail.com: Mar 14 05:12PM -0700

On Wednesday, March 14, 2018 at 2:51:47 PM UTC-5, Terry Schwartz wrote:
> Well the dealer makes more money/hour on out of warranty service than in warranty service, so that is the probable reason they would rather you paid than the OEM. Also it takes some time to contact the OEM and get approval, and you were there waiting. Their initial quote was pre-contact.
 
I think that was pretty shitty of them. Some manufacturers might not like that and it could jeopardize their ASC status. I have done warranty work in brownwares and some of them are ridiculous. But this concerns their public relations.
Terry Schwartz <tschw10117@aol.com>: Mar 15 09:25AM -0700

Brownwares?
 
gregz <zekor@comcast.net>: Mar 15 08:25AM


> ** No way you will ever create a significant inrush surge by doing that.
 
> .... Phil
 
Thought not, but I expected to see a lot more. It's not immediate break
down. It takes 1-3 seconds. I'm still inspecting parts down the line.
 
Greg
jurb6006@gmail.com: Mar 15 03:31AM -0700

On Monday, March 12, 2018 at 10:53:38 PM UTC-5, GS wrote:
> up. Not sure if replacement resistors are suitable. Thinking now of upping
> power from 2 watt types.
 
> Greg
 
If you are talking about R 660 and 680 I would be suspicious of C 661 and 681. There is a slight possibility that one of them, maybe more likely 661 has a weird failure mode in that there is leakage at zero volts which is "blown" clear once the voltage gets to it. It is a bit rare but at the age of that thing you can get failure modes that are not usual, as with anything.
 
Looking at the circuit I see nothing else that could be the problem. And as for them being the wrong type of resistors, why did the originals fail in the first place ? i don't know about you but I haven't replaced many resistors in that place in a circuit without finding some sort of a short.
 
The direct, unregulated supplies go through R 677 and 697 which limits current to where it should not blow your inrush limiters even if all four outputs are shorted. That would be 500 ohms and being much higher than 10 ohms those resistors would blow first.
 
The only other thing hanging off those supplies are tube plates, and you can eliminate them as a possibility by simply removing V 667, 677 and 697. Everything else is to high value resistors and no matter what the possibility of those shorting out is so remote it isn't even worth consideration.
 
The possibility or the wrong replacement resistors being the trouble while remote, is a possibility, but only if the replacements are smaller in size and therefore have less thermal mass. Some newer resistors can take higher temperature thus being able to dissipate more power when they are physically smaller. That situation might be ameliorated by using with 2 5 ohms in series or 2 20 ohms in parallel.
 
In theory raising the value should not work as overall dissipation will be higher, and lowering the value which might save the resistors will put more stress on the input filters and/or the rectifiers.
 
So the first thing I would do is to disconnect the original filters and wire in some 470 uF @ 250 volts and see what happens.
 
Worth a shot I would say.
jurb6006@gmail.com: Mar 15 03:36AM -0700

Wait, it is blowing all three ? Hmm, that stickies up the wicket now. That makes it more likely that you will have to go with the dual resistors in each place.
 
Much more likely, to the point where I wish I could edit the other post. That is now the most likely.
 
It might be alright to go with higher wattage resistors, it still has a fuse.
 
In this case the only other possibility is the transformer is putting out too much current and that, well, think you can win the lottery two weeks consecutively in a row ? (playing only one number each time)
Phil Allison <pallison49@gmail.com>: Mar 14 06:01PM -0700

GS wrote:
 
---------
 
> I think PB Blaster will melt polystyrene. Not sure about W40.
 
** The solvent in WD-40 damaged does not damage any of the plastics commonly
used in electronic or electrical components.
 
In normal use, the solvent evaporates in 10 to 15 minutes having done its job of softening the contaminating material so merely operating the switch, pot or connector completes the cleaning operation.
 
 
 
.... Phil
gregz <zekor@comcast.net>: Mar 15 08:15AM

> significantly from the next.
 
> Oh, and it's far better on locks than graphite.
 
> And terrible on an airgun. (at least on a springer)
 
Im satisfied with the description of mineral spirits and light mineral oil.
I laugh some say fish oil. Upon investigating, there seems to be a trace of
bug oil. I think it was a variety of stink bug. LOL.
 
Greg
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