5160 motherboard is giving me trouble

[josephdaniel]

Ok, I decided I should create a new thread for this since it was very off topic in the hard drive thread.

Last night I was attempting to get a copy of a ROM that is installed on a card in my 5160 and I got the files off of it and them immediately turned it off it was working fine at this time. About an hour later I went back and turned it back on and the computer was going incredibly slow and was giving me random 301 errors on start-up so I cleaned the connector on the keyboard and tried it with two other key boards with the same results. When ever it would display new text on the screen it would "beep it out via the speaker) and when executing commands from the autoexec.bat file it would stop mid line in a command and not move for several seconds.
This morning I removed each card one by one the see if any of them were the problem and none of them were so I removed the motherboard and checked all of the small film capacitors on the board. All of them were good. So I have decided that it must be a dying chip on the motherboard or a cold solder joint.
Any one got any ideas on what it may be?

 

[modem7]

The solder joints of the keyboard DIN connector are subjected to stress every time that a keyboard is connected or disconnected. There may be a damaged solder joint there.

 

[josephdaniel]

I just looked at the DIN connector and there are no cold/cracked solder joints on it but I will re-flow them tonight and see if that fixes the problem. I was thinking that it might be possible thet the pins inside the connector have worn out, but then I wondered why they would have stopped so randomly without me having moved the keyboard?
I am also going through all of the sockets since many of them have a considerable amount of dust/dirt buildup in them, and I need to check the power supply too this evening and open it up and drag out my cap tester (if I can find it) and test a few electrolytic's to see how bad they're leaking.

 

[josephdaniel]

I just re-flowed the solder joints with my soldering iron and even though they didn't look like they were cracked/stressed it fixed the problem.
I'm gonna see if I can get that ROM file to you this evening too now that my computer is back up and running

 

[EverythingIBM]

Did you recap the power supply with fresh electrolytics?
Did you check for any failed tantalum capacitors? (use a multimeter).

These components have to be replaced after 30-some years.

I don't think it's a dead chip, sounds like a component problem if it slowly starts to deteriorate like that. A dead chip will cause an [immediate] problem.