EZ-go fix; followup

Although my wifey claimed the problem came and went periodically, it was solid-bad when I got it. Thank goodness!
I popped the cap off the controller box, and could find nothing loose,
corroded, or burnt, so I took the plunge, pulled the controller and pried the plastic cover off. Damn hard to get off; but it was just held by little snap-grooves/clips.
Magnifying glasses are great things! It was a cracked run to one end of a resistor. The pad had separated from the trace right where they join (probably thermal), and showed just a bit of messiness on the broken edges -- sort of "folded upwards". It was a big enough crack to be pretty obvious, and that's good because my vision ain't what it used to be.
I scraped off the conformal coating, soldered a wire across the crack, and put some glyptol (stolen fingernail polish from HER) over the joint.
BINGO. Cart runs.
Thanks for all the suggestions, guys.
LLoyd
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On Wed, 27 Jun 2012 15:31:03 -0500, Lloyd E. Sponenburgh wrote:

If it was a cracked board then it probably did come and go -- at first. Then as the board kept flexing and the copper got folded upwards (and away) more and more, it would have worked less and less.
If you don't have it buttoned up yet, go over the _rest_ of the board for any incipient cracks. If you can, run the cart while flexing the board (both directions is best) -- that'll maximize the chances that a crack that hasn't shown itself yet will open up on you.
--
Tim Wescott
Control system and signal processing consulting
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I inspected it closely, top and bottom, and didn't catch anything else, but it's pretty hard to flex it while mounted. It's deep inside the battery compartment, and out of reach to the driver because of the weird angle you'd have to bend your arm.
I do know what to look for, and especially looked for large components that aren't heavily mounted. Vibration will do the same thing as actual board flex.
LLoyd
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Lloyd E. Sponenburgh wrote:

Good on you and maybe you were fortunate it was power electronics and still large enough to see. I've got a bit fed up of trying to fix things a mates son has damaged in the consumer electronics line and trying to solder items with a 1mm tip and a 10x eyepiece to see the parts.
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On Wed, 27 Jun 2012 15:31:03 -0500, Lloyd E. Sponenburgh wrote:
(...)

YeeHa!
Well done.
--Winston
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"Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote in message

Aside from dried out capacitors, failed solder joints are probably the most common failure mode with electronics these days--especially common at the point where discrete components, headers, terminal strips and so forth are attached onto the board.
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"Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> writes:

Attaboy. The loser approach is to bridge the crack with solder; which does not last. It's best if the wire has a hump to allow some slack/flexing.
--
A host is a host from coast to snipped-for-privacy@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
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Yeahhh.... I knew that... have done it before. Didn't do it. Damn.
Oh, well... it'll keep at least as long as it did. It's an '03 cart.
LLoyd
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On Wed, 27 Jun 2012 15:31:03 -0500, "Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote:>Although my wifey claimed the problem came and went periodically, it was

Congrats, LLoyd. Cheap fixes are always the most fun.
My fix was a new 1' long battery cable on the Club Car.
-- Always bear in mind that your own resolution to succeed is more important than any one thing. -- Abraham Lincoln
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On Jun 27, 3:31pm, "Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote:

Good catch!
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On Jun 27, 3:31 pm, "Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote:

-Good catch!
Or long experience.
I've done field-service board diagnosis and repair. For power circuits examining the board for discoloration or cracks reveals a large fraction of problems, even with surface-mount. Wiggling mechanical connections catches another bunch. I didn't have to dig into the circuitry to find the fault very often.
jsw
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Yup, and I hail back to the "big linear power supply" days, so there were a lot of high-current, high thermal effect PCBs developing that sort of problem.
You get very accustomed to looking for the usual suspects, and 60-70% of the time that's where the problem lay.
It's a good thing I didn't have to "dig into the circuitry" too far, because schematics for those Curtis controllers are unavailable. I can't even find any reverse-engineered ones, not even for sale.
LLoyd
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"Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote in message

When I was in the business of fixing power wheelchairs I still couldn't get help from the manufacturers, only $$$ replacements for newer controllers.
That was an alarming look at what happens to costs when the government pays them, similar to prevailing-wage construction. Even military research wasn't as bad.
Or maybe I was unusually frugal with taxpayer money. No one ever questioned my purchase orders for electronics and machine shop work, so I don't know.
jsw
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A friend of mine commented that when the artificial prize goes to zero, the demand jumps to infinity.
Christopher A. Young Learn more about Jesus www.lds.org .
When I was in the business of fixing power wheelchairs I still couldn't get help from the manufacturers, only $$$ replacements for newer controllers.
That was an alarming look at what happens to costs when the government pays them, similar to prevailing-wage construction. Even military research wasn't as bad.
Or maybe I was unusually frugal with taxpayer money. No one ever questioned my purchase orders for electronics and machine shop work, so I don't know.
jsw
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I've had only sporadic luck in fixing electronics. A gym-duty Lifefitness treadmill went that I had purchased used went out on me when I moved to a new state. It seems like the EEPROM lost its memory and Lifefitness wanted $1200 for a new board (it has an Emerson inverter AC drive). No help finding schematics or selling me a new chip. I found another used one and cannabalized the old one for parts. Lately I've had a Toshiba DVD player that won't play a whole movie. I've pulled out and reseated ribbon cables, but I think it will soon end up in the trash.
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On Thu, 28 Jun 2012 07:09:46 -0700, Denis G. wrote:
(...)

A little naphtha on a cotton swab to carefully clean the lens in the DVD mechanism can really help in situations like this.
--Winston
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I'll try it, but the problem seems that the beginning of the movie plays fine, but towards the end it starts pixellating and then just freezes up. I thought it might be a buffering problem, but every time I played with it, it seemed to get a little better. Unfortunately, it seems to be more like a Zeno's Paradox problem which will probably end up being solved with a big hammer.
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Winnie, you nailed it! Thanks.
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On Thu, 28 Jun 2012 09:09:57 -0700, Denis G. wrote:

BFH. The ultimate troubleshooting tool.

Certainly. :)
--Winnie
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