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Author Topic: Fixing Fat Angus  (Read 1311 times)

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Offline BOfHTopic starter

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Fixing Fat Angus
« on: January 23, 2025, 05:33:33 PM »
Hi all, I've been trying to fix my Amiga 500, which has been in the loft for many years.  Initially, it was getting as far as a white screen without the insert disk image.  As part of troubleshooting, I interested a Diag ROM.  The ROM seemed to get stuck asking to hold down a key on the keyboard or pressing the right mouse key. Both actions did nothing to progress the Diag ROM.  Trying to figure out what was wrong, I read some advice about reseating the board chips.  I did this.  Following the reseating of Fat Agnus, the ROM started getting stuck at "No memory found.  System halting".  Oh dear.  I tried removing Fat Agnus and it did seem like one of the pins was out of place.  After reinserting, I still had the same issue.  After a couple of attempts at reseating, it still had the same issue.  I noticed that it looked like maybe one of the pins in the socket might not have been making contact with the cihip, so I pushed it out a little and the bloody thing broke straight off the socket :-(

I was hoping for some advice on the best way to resolve this issue.  I'm not sure if I should have a go at desoldering and fitting a new PLCC socket to the board or if there is some other crafty fix that anyone knows that might allow one to fix/bodge/over come the broken pin?

Thanks in advance.
 

Offline Munchkin

Re: Fixing Fat Angus
« Reply #1 on: January 23, 2025, 06:20:02 PM »
I know replacing that socket isn't the easiest but in this case I think it's the best thing to do. Those old sockets were never of the best quality from the start and age hasn't done them to well  either. Starting to try and fix it in place is probably gonna make things worse and you might end up causing more damage that's harder to repair.
 

Offline Castellen

Re: Fixing Fat Angus
« Reply #2 on: January 23, 2025, 06:52:47 PM »
Absolutely, if the IC socket is even slightly questionable, replace it.  New PLCC sockets are not expensive and easy enough to source.  If you don't have the tools and skillset to unsolder it, take it to someone who does, else you're likely to cause more damage to the plated through holes and PCB tracks.  It only takes a few minutes with the correct tools.

Even if you manage a 'repair' on the damaged socket, you'll still have the other intermittent issues that will likely cause ongoing problems long term.

Be sure to clean the leads on the IC as well; isopropyl alcohol on a soft cloth.  Don't bend the leads as they're easily damaged.  And avoid contaminating the cleaned leads with finger grease after you've cleaned them.