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Unread 05-18-2012, 07:39 AM   #46
JS97ZJ
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Quote:
Originally Posted by AAA View Post
I think I'll wait a few more weeks before sealing up the PCM for good, but so far so good.
My PCM hasn't been sealed up yet, (2yrs.) It bonded itself back in. Heat I guess. I'll get to it.

Glad to hear it worked out for you guys. I think there's a whole lot more out there that could benefit from a little extra solder.

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Unread 05-19-2012, 03:23 AM   #47
coralman
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JS it looks like the solder fix is jeep wide. I saw a video on repairing the abs controller that I gonna try this weekend. So we have pcms, headlight dimmer switches, VICs, and now ABS. Thats alot of funky soldering.
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Unread 05-19-2012, 09:30 AM   #48
cootertwo
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Like I said somewhere else, wasn't it about the time of our Jeeps, that the EPA was cracking down on lead content in solder? I remember some of the first low lead crap that came out was about the same as using JB weld. Just an opinion out of my 62 yr old head.
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Unread 05-19-2012, 11:37 AM   #49
JS97ZJ
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Quote:
Originally Posted by coralman View Post
JS it looks like the solder fix is jeep wide. I saw a video on repairing the abs controller that I gonna try this weekend. So we have pcms, headlight dimmer switches, VICs, and now ABS. Thats alot of funky soldering.
My ABS hasn't worked in years. All of the sensors checked good and the spacing was fine. Don't tell me the solder connections in the controller are f'ed too....

Quote:
Originally Posted by cootertwo View Post
Like I said somewhere else, wasn't it about the time of our Jeeps, that the EPA was cracking down on lead content in solder? I remember some of the first low lead crap that came out was about the same as using JB weld. Just an opinion out of my 62 yr old head.
The silver and lead solders are compatible when reflowing joints. I have lbs of old stuff.
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Unread 05-19-2012, 05:16 PM   #50
coralman
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Yep, you tube video shows its mostly the power feed joints that go bad on the controller. OP said that in that time frame alot of high draw joints were failing on boards.
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Unread 05-21-2012, 12:51 PM   #51
kalpol
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THANKS for this procedure. I have a 96 and it was stalling randomly without codes (once threw some random code, I forget what it was now). The PO replaced many parts, I replaced a few, then found this article and suspected the computer. I poked at it while the engine was running, and when I wiggled the center connector, it stumbled for a second.

So I dived in and got things apart. Instead of using the knife to cut away the edges of the potting compound from within the case, I just used the torch to heat the edges to loosen the stuff. It took a really long time so much patience is required, and don't let boiling compound shoot out and hit you in the face. Then I (gently) cut a channel in the compound with the knife over the pins, then removed that strip of compound with acetone, my fingers, and a very stiff plastic brush (which worked well if brushed in one direction). I just reflowed the center plug pins, temporarily put it all back together and no more stalling. I am really pleased this worked.
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Unread 05-21-2012, 04:40 PM   #52
coralman
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Scored my third 513AB on the cheap. This is the one I'll tear into most likely. Didn't make it the abs this weekend. Between pressure washing the house, changing my oil, and power steering fluid, adding freon to the wj, washing the zj and cleaning the interior, fixing the crap the people that my landlord got to redo my bathroom left, I just did't have any more left and fell victim to the michelob
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Unread 05-22-2012, 12:30 PM   #53
JS97ZJ
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Quote:
Originally Posted by kalpol View Post
THANKS for this procedure. I have a 96 and it was stalling randomly without codes (once threw some random code, I forget what it was now). The PO replaced many parts, I replaced a few, then found this article and suspected the computer. I poked at it while the engine was running, and when I wiggled the center connector, it stumbled for a second.

So I dived in and got things apart. Instead of using the knife to cut away the edges of the potting compound from within the case, I just used the torch to heat the edges to loosen the stuff. It took a really long time so much patience is required, and don't let boiling compound shoot out and hit you in the face. Then I (gently) cut a channel in the compound with the knife over the pins, then removed that strip of compound with acetone, my fingers, and a very stiff plastic brush (which worked well if brushed in one direction). I just reflowed the center plug pins, temporarily put it all back together and no more stalling. I am really pleased this worked.

At first I was hesitant on posting this fix because of the use of a torch to get the computer out of the case. But I see it can with stand alot more heat than I could imagine. I still wouldn't recommend heating it up without first using a knife along the sides. Like you noted it could build up excessive pressure and spew out molten compound that could cause a pretty painful burn.

You also used a knife on the back? If you would have cut too deep, you might have cut through the traces and made more of a problem.

I didn't make the notation about brushing the compound off in one direction, which was the best way to clean up the board.

I'm happy this is working out for you guys that have given it a try.
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Unread 05-31-2012, 12:29 AM   #54
ElTejano
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I would reseal that board with dielectric silicone gel again to avoid future problems due to corrosion.

These 2 seem very similar, I see the only difference being the color. One is the store page from the Elssworth Adhesives website to buy and the other link is the product page from the maker, Dow Corning.

http://www.ellsworth.com/dow-corning...een-210ml-kit/
http://www.dowcorning.com/applicatio...EN&DCCSF=112EN

http://www.ellsworth.com/dow-corning...lue-210ml-kit/
http://www.dowcorning.com/applicatio...N&DCCSF=3084EN

I will be ordering this gel to replace the gel I removed from the ECm. I recommend others do the same unless you want problems down the road.

I did this repair along with cleaning the pins with a little sandpaper and connectors with a small file that I ground down to the same size as the pins, measure it all precisely with calipers.

I also took a brass brazing rod and ground it to the same size as the pins as well and used it as a gauge to see if the connectors and too loose. On my 97 JGC, a lot of the connectors were way way loose. Took the connectors apart and slightly crimped each one til it was slightly snug. Eaily reassembled them and that did the trick.

With my other JGC, the connectors were fine, nice and snug but I still cleaned them with the fie. It was the ECM that was causing the problem and I did the repair outlined in this thread and it runs great now.

I will eventually replace all the connectors with new ones.

This thread is probably the best write up int he whole forum. Thanks for posting it.

Last edited by ElTejano; 05-31-2012 at 08:05 AM..
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Unread 06-02-2012, 01:06 AM   #55
framanda
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My jeep has been stalling cutting out and having an intermittent miss for a few months now so i figured i would tear into the pcm and cure the problem. Well when i got in there i found this, you could see a dark patch under the potting compound and when i started peeling it away it was fried, the piece of wire came up with the potting compound. Any ideas what would cause this? for reference its the s shaped wire on the right in the bottom pic.

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Unread 06-02-2012, 07:16 AM   #56
ZeeJay1997
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Quote:
Originally Posted by framanda View Post
see a dark patch under the potting compound and when i started peeling it away it was fried, the piece of wire came up with the potting compound. Any ideas what would cause this? for reference its the s shaped wire on the right in the bottom pic.
What I see is that something has lifted off the board. Looks like more than "a wire" is missing. It could be repairable depending on what is missing besides part of the trace. JS may have a better answer when he gets on.
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Unread 06-02-2012, 07:58 AM   #57
coralman
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Almost looks like that was a "cushion " of some sort. Did you look through the potting to see if you could find any pieces? JS is da man when it comes to this repair like ZeeJay said.
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Unread 06-02-2012, 11:52 AM   #58
JS97ZJ
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Quote:
Originally Posted by framanda View Post
I had always thought that these snake like sections of print on circuit boards were protection areas similar to inline fuses.
I've never seen one blown out like that, but I'm definitely looking into it. t looks as though there was a protective square area under that portion of the board that was isolating the print.

here is the the way it looks in good condition....
unknown1.jpg  
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Unread 06-02-2012, 01:46 PM   #59
Oldfrog
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If the copper cladding has de-laminated from the fiberglass, you can take a piece of insulated wire....(maybe 22- 24 gauge )and solder it to the cladding where it's still stuck to the fiberglass on each end. Just be careful and dont strip too much insulation off each end for soldering. I used to build PC boards for a living and we did this quite often in a pinch. That zig zag you see is more than likely an afterthought...to increase resistance slightly or slow a signal down because it was screwing with the circuit's function....but who knows?
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Cajun Recipes and Fishing tips

Words of wisdom, Posted by Zeejay:
"..it's not air, it is the opposite of air... suckage so to speak."

Stalling? Work through Zeejay's list
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Unread 06-02-2012, 04:03 PM   #60
framanda
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Quote:
Originally Posted by coralman
Almost looks like that was a "cushion " of some sort. Did you look through the potting to see if you could find any pieces? JS is da man when it comes to this repair like ZeeJay said.
Yea the potting compound looked chard with remnants of trace stuck in it.
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