QL freezing after an hour

[stevepoole]

Hi Mark,
I was bugged by intermittent freezing , until I checked the mains plug, and found a dodgy connection....? Steve.

[Popopo]

Congrats!

edit: based on what you are telling, it sounds a lot about bad sitting ICs on the sockets.
Whatever, congrats!!!

[markdryan]

edit: based on what you are telling, it sounds a lot about bad sitting ICs on the sockets.
Whatever, congrats!!!

I agree, it does and I did consider replacing the ZX8301 socket as well, just in case the socket was at fault and not the ULA. Having said that though, I had previously cleaned the socket and removed and re-seated the old ULA multiple times, before eventually replacing it. It's only when I replaced the ULA with a new one that the machine stopped freezing. The old ULA looks to be in good condition. Its pins are straight and clean and oddly it wasn't getting that hot. If the problems do re-occur I might replace the socket.

The machine ran for another 110 minutes this evening without issue.

I think the plug and the power connector are okay. Wobbling them doesn't produce any instability. I had previously reflowed the power connector. If the issue does come back, I will double check the plug and power supply. Thanks for the hint.

[ql_freak]

I'm having some issues with my QL (Issue 5). The machine boots up fine and works without issue usually for about an hour before freezing. When the machine freezes there's no screen corruption. All that happens is that the cursor stops flashing and the computer stops accepting input. If I press the reset button the machine resets without issue, passes the Minerva memory tests, and boots normally.

My real QL (not switched on for over 20 years!) has had the same problem. Cure: RESET or even better: Switch off and on again.

It will work fine for about 10 minutes or so before freezing again.eys continue to make the clicking noise even after lots of presses.

That's not the case with mine, after the first freeze (crashi) it works for days (weeks, if no bad software crashes it [the QL does not have memory/process protection in hardware as modern machines have]).