-----Original Message----- From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Fred Cisin Sent: Tuesday, September 6, 2016 11:36 AM To: General Discussion: On-Topic and Off-Topic Posts <cctalk@classiccmp.org> Subject: Re: SWTPC 6800 weirdness
On Tue, 6 Sep 2016, Brad H wrote: > My 6800 has been mostly working, but it seems to be occasionally > flaking out. I don't know why. Sometimes you go to power it up, and > there's no response on terminal side. The 'fix' is sometimes to > wiggle the memory/CPU boards and then for some reason it's fine(ish). > There are five cards fix by wiggling implies a bad connection. possibly due to oxidation or corrosion of connector? Depending on how vigorous the wiggling is, it could even be bad connection between a chip and socket, or even tiny damage to a trace on the board. > Today it flaked again and would not come back up, so I pulled the MP-M > board and the MP-A board and swapped slots. It came up, but memory at $0100 was > missing. I tried powering up, swapping slots, etc.. same deal. Then I > left the machine for an hour, powered up again.. boom.. now $0100 is back. >Working later could be a thermal problem, or just random chance. There is definitely some oxidation around the board and on some pins, which I thought I cleaned well enough on the particular slots I'm using. I'll check again. It seems odd that mechanical fooling around makes it work. Could be totally coincidental though. I've been a bit hesitant about taking the board out as I worry about fragility.. but I think we're past that now.
