2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

follow up on power steering computer

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Old Mar 13, 2005 | 09:55 PM
  #1  
DC350's Avatar
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From: British Columbia
follow up on power steering computer

Icemark/hailers i know that you have pinned it down to some cold solder points on the computer board for the power steering.. As it has been cutting in and out. Have you found out which one(s)?

Evan
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Old Mar 13, 2005 | 10:44 PM
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From: Rohnert Park CA
On the 5 that I have on my bench, that I have been tracing down cold solder joints, I have found some intresting things.

#1. units made after 7/87 (the 88 model year and later) seem to be missing the buzzer, and have a small resistor in place of the buzzer. So if there were any error codes, on the 88 and later ones, the buzzer failure indicators would never go off (unless you soldered in a buzzer- which I have been doing and it works fine).

#2, the majority of the cold solder joints are either in the plug where it meets the circuit board (surprise surprise ) OR in the first set of transistors next to the plug. In fact 3 of the 5 I have been working with, had bad solder joints on the actual transistors. This is very uncommon.
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Old Mar 13, 2005 | 10:48 PM
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From: British Columbia
Very strange about #1....

And sounds like most of the board needs to be resoldered... I might have to yank it out and give it a touch up... Is it hard to resolder the area around the transistor w/o damaging the transistor?
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Old Mar 13, 2005 | 10:51 PM
  #4  
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From: Rohnert Park CA
Originally Posted by DC350
Very strange about #1....

And sounds like most of the board needs to be resoldered... I might have to yank it out and give it a touch up... Is it hard to resolder the area around the transistor w/o damaging the transistor?
Transistors are very sensitive to overheating. Make sure you only heat up one leg at a time remove and reflow new solder, and then move to the next one.
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Old Mar 14, 2005 | 08:06 AM
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From: new jersey
Mark,
Have any of the re-solders you've done had any effect on the problem we've been having with the PS cutting in and out? I bought a used PS computer recently, and - surprise surprise - it has the same problem.

Pete
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Old Mar 14, 2005 | 08:26 AM
  #6  
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Hmmm...this is interesting. I always thought mine went in and out because I put it in and wasnt sure if I clamped a line or somethin! This may be the cure to my PS problems also!

So...where is this PS CPU anyways?
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Old Mar 14, 2005 | 09:01 AM
  #7  
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^ Look under the dash, just to the left of the steering column. You'll see an aluminum box about 4 inches square and 1 inch thick. It's held in by 2 bolts.
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Old Mar 14, 2005 | 09:08 AM
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^^Sweet..thanks. Will pull it out tomorrow.
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Old Mar 14, 2005 | 09:12 AM
  #9  
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From: Rohnert Park CA
Originally Posted by nopistons
Mark,
Have any of the re-solders you've done had any effect on the problem we've been having with the PS cutting in and out? I bought a used PS computer recently, and - surprise surprise - it has the same problem.

Pete
All the units had intermittent operation, when either hot or cold, but all seemed to fail once the temp was stabilized (for example, some didn't work cold, two didn't work when they got warm- but started working again when the car sat and got cold again.)
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