Quote:
Originally Posted by Hammered 77
Hatzie, what's the likely hood of a module from 78-82 Corvette or Camaro working in our trucks?
Rick
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If it plugs in it'll likely work.
You're likely to run into the same old "dried out" electrolytic capacitor issue as the one you have.
They aren't difficult to replace but I wouldn't do it with a WalMart 25W or 40W iron and a solder sucker or braid. You need better thermal control.
Here's a commentary about electrolytic caps.
https://silentadmin.gsans.com/my-lib...pacitors-fail/
Here's Dave Jones tutorial about Capacitors. He goes into electrolytics and how they fail and why EEs still use them with their known issues.
Get good name brand Rubycon or Nichicon electrolytics rated for as many hours of runtime as you can get. Panasonic are made by Matsu****a now and I won't use them. ***EDIT. I guess the board figures i was cussing and not typing a Japanese manufacturers name.
You want the same or slightly higher voltage rated, same or higher thermal rating, with the same capacitance. Modern caps are generally smaller than the caps from the 70's & 80's with the same ratings as the old ones.
Electrolytics are polarity sensitive. These PC boards have no silkscreen so you'll want to carefully replace the caps one at a time. I mark the negative leg of the capacitor on the PC board with a sharpie so I can assemble the new part in the proper + to - orientation.
If you install an electrolytic cap in reverse polarity you'll get a big POP - BANG when the power is applied to the cap. It makes a nasty mess. Tantalums catch fire so they tend to be very exciting too.
Not that I've installed either type in reverse polarity... I've just heard about it.
I am very careful but honestly it's only a question of when you'll screw up and have to clean up a mess & install a replacement cap in the proper polarity orientation.
I don't completely trust the silkscreens anymore either. I repaired a dodgy power supply on my Tek 2465A scope and got a nasty surprise. I got a big POP-BANG when I plugged it in and switched on the power strip after replacing a raft of capacitors.
The exploded cap was marked for the wrong polarity on the silkscreen. It was obvious what leg was attached to the output ground plane when I checked it with a meter. The hole for that leg was not marked properly. That was an eye opener.
Thankfully I hadn't plugged in the output for my smoke test.
To add insult to injury the Technician Manual schematic and parts list was incorrect as well. I'm not sure whether this was a manufacturing update that didn't make it into the manual or I have the manual for an earlier or later minor revision of that scope or someone played swaptronics with the power supply over the last two or three decades. All equally plausible. My manual now has notes in pencil.