exxos's Atari, Amiga & retro forum

Hi everyone,

I think this is a bit of a long shot but I'm going throw this out there anyway in the hope someone has an idea to help from my self inflicted doom...

I've had a self-built TF1230 for a couple of years now which has been rock solid from day one on my 1D4 board. Yesterday it started freezing seemingly randomly. The only change to the A1200 recently was installing an FPU on the motherboard, clocked at 28Mhz, but that was a good few weeks ago. It was the best part of 30 degrees down here yesterday so I wondered if heat was a factor, given the increasing frequency of freezes after initial power on.

So, I stuck a small fan in the case and pointed it at the CPU, and it seemed to do the job. Then I thought I'd try swapping out the CPU in case it was marginal at 50Mhz. After a couple of CPU swaps with no improvement I got lazy and did another couple of swaps without removing the 1230 from the motherboard and without properly supporting it underneath. The board flexed a fair bit but nothing untoward seemed to happen. However... after the last swap, I can no longer boot with KS 3.1, I just get a dark grey / black screen. There is no access to the early startup menu. If I remove the 030 Enable jumper, 3.1 boots fine. Diagrom is fine with the 030 enabled, detects 256MB as it normally does, and passes memory tests from 08000000 to 0C000000 if I point a fan at the CPU (it's still hot here!). KS 3.0 boots but if I Addmem the memory it freezes within a few seconds.

My gut feel is that I damaged something on the RAM / CPLD side by over flexing the board. I've reflowed everything except the birdseed on the underside (sockets, RAM, buffers, CPLD etc) without success, and just to rule it out, I erased and re-flashed the CPLD. No dice...

Oddly, the symptoms are identical to this viewtopic.php?t=6001 post from a couple of years ago, but I've tried removing everything from the board including my (short) IDE cable without joy.

Does anyone have any ideas on further troubleshooting I could try? I hate to have killed my 1230 with my own hands!

I made some progress today after checking continuity on what seemed like hundreds of pins... probably because it was :lol:

I've lost continuity from the CPU pin closest to the CPLD (A13 which according to the schematic is one of the address lines) to the CPLD. I don't imagine that is a good thing to loose. I also found that if I applied pressure on the CPU in that area I could get it to start to boot, albeit very unreliably. So I'm pretty sure my issue is a damaged CPU socket from my wrestling with it yesterday.

Tomorrow's job... check the remaining CPU pins and then set about replacing any broken ones.

Fixed!

Swapped out the pin with no continuity for a fresh turned pin socket salvaged from a strip, and after a bit of trouble getting continuity to the pad on the top side of the board (maybe this is where the original break was), we're back up and running. It looks a little bit janky as the replacement pin is a tiny bit taller than the rest, but it doesn't seem to cause any issues. f I ever stumble across a fresh 68030 socket I'll swap the whole thing out.

Added bonus, so far no sign of the original overheating problem that set this whole course of events in motion. So either the re-flowing of everything sorted that, or the fact the ambient temp is 10 degrees cooler today is helping.

:)

Good job :)