The way I would pull the 8255 socket would be to cut the legs of the socket then you can heat each pen and pull out one at a time – that way you don’t have to try and heat all the pins at once – same way with a dead ic chip just cut the legs.
From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Don Caprio
Sent: Thursday, March 22, 2012 4:35 PM
Subject: [N8VEM-S100:764] Advise on restoring old boards
I recently won an IMSAI front panel board on eBay. Just received it in the mail today and
boy is it in bad shape. Looks like it was sitting around unprotected for the last 25 years.
Could of even been outside.
I'm curious how some of you would go about restoring this board. All of the LED and capacitors
were bent over. Some caps are chipped and cracked. I was able to straighten out the LED's without
breaking any pins (hopefully). The top of the board has a thick film of dirt and grit. All of the IC's
Here's my plan of attack:
- Brush down the board with a clean paint brush and remove all the lose dirt.
- Blow the board off with an air nozzle from my compressor. The compressor does have a oil and water filter.
- Immerse board in a PCB cleaner solution and scrub with a tooth brush
- Remove all of the IC's (Can't remove the 8255 without unsoldering two switches).
- Do another board wash.
- Clean S100 connector with pencil eraser to clean up contacts.
- Insert board in backplane and test the 7805 voltages. Replace if needed.
I was considering replacing all of the LED's, filter capacitors and voltage regulator.
I'd really like to remove the 8255 socket and replace with a low profile socket.
The current socket is preventing the two switches from lining up with the others. They stick up about 1/32 of an inch. The switches are resting on the 8255.
I'm a bit nervous about unsoldering and replacing components not knowing what sort of abuse the traces can take.
Your words of wisdom and experience is greatly appreciated.