Crashing A1200

[maffoo]

Hi,

I've just got hold of a second-hand A1200, complete with hard disk, 030 accelerator (a Turbo 1230 Mk II, which I think is 50MHz) and 22MB RAM. It arrived on Wednesday and seemed to work fine, although I didn't do much with it. I basically just checked it was working, but I didn't have any way to get software onto it (my CF->PCMCIA adapter hadn't arrived.)

Yesterday my order (including the CF adapter) from Amigakit arrived. I replaced the 3.0 ROMs with 3.1 so I could install OS 3.5 and everything seems to boot OK, then the Amiga will suddenly reset itself for no apparent reason. I don't even have to be doing anything, it's happened while I'm playing games but today I've noticed that it will reset if left alone for a while.

I've noticed that the 030 gets very warm, I've taken the trapdoor cover off and raised the  front of the computer slightly to try to improve cooling a bit but it's still not stable. Earlier on it reset itself twice in a short space of time, making it look more like a CPU overheating problem.

Is it likely to be the CPU getting too warm? Or is there anything else it could be?

Thanks

Matt

[maffoo]

Brian wrote:
What you describe there could just as well be power failure... what PSU do you use for the system?

It's just the bog-standard A1200 PSU (which I suppose is a nit long in the tooth - maybe it's on it's way out?)

I've just taken out the accelerator and booted the computer to see if it still crashes, and sadly it did (after only 4 minutes :-( )

[maffoo]

Thanks motorollin, I'm trying it now (just the monitor and power connected, nothing else. (I was hoping the hard drive wouldn't be a problem as I've swapped the one it came with for a CF card, which AFAIK needs less power.)

I had a quick check of the motherboard while I was taking the accelerator out and I couldn't see any problems there.

I was also wondering, if it works fine from the workbench floppy could it indicate a problem with SetPatch (maybe it doesn't like my A1200's motherboard revision or something, and makes it unstable?) If that's the case, I can always reinstall 3.0 and Ebay the 3.5 CD...

[maffoo]

Thanks for the advice. I've tried filling and purging the RAM, it seems to work when it's just Chip RAM but when I had the 16MB SIMM in it caused a crash. However with the CF card attached the machine crashed even when it was booted from floppy, so maybe the SIMM's power requirements just pushed the PSU over the edge. I've also double-checked that the ROMs are seated properly, that doesn't seem to be a problem.

I'm going to try to get hold of an A500 PSU (there are some on Ebay, I've e-mailed the seller to confirm if they're 50W or 25W.) I was considering upgrading to a D-Box tower eventually, so once I've confirmed that the PSU is the problem I might get it towerised so it will have 350W to work with  :-D

PS. Amigakit, I noticed that you have Amiga PSUs on your site, are they 50W? If so I might be placing another order with you!

[maffoo]

Homer wrote:
Might be worth mentioning where you live to see if you can borrow one for fault finding :-) Much cheaper than buying one !

Good idea  :-) I live in Leicester (England.) Any help would be greatly appreciated!

[maffoo]

Thanks for the advice everyone, I've got hold of an A500 PSU and the A1200's run for over an hour without crashing, so I think it was the PSU.

Just out of interest, is the A1200 PSU any use (eg. can it be fixed?) Or should I just chop the power connector off in case I ever want to adapt an AT PSU and throw the rest away?

[maffoo]

Homer wrote:

the A500 psu will slowly overload and may eventually die the same way as the weaker A1200 psu

Sorry if this is a stupid question, but how likely is it that the A500 PSU will overload? I had a look at Epia Center's Power Simulator to get an idea of the power reqirements of 2 CF cards (one in place of the HDD and one in the PCMCIA slot) and it looks to be around 1W for the pair. The comp.sys.68k FAQs say the 030 should take 2.6W, so say 10W for the whole card. Assuming the A1200 itself needs all the power from its original 25W PSU, this brings the total to 36W, which should be well within the A500 PSU's specs (it says 60W on the bottom.)

(I expect the figures I've quoted for the Amiga and accelerator are way out - hopefully I've over- rather than under-estimated the power requirements!)

I'm considering putting the computer in a tower eventually so hopefully the PSU won't be an issue, I'm just wondering if it will definitely overload. (I suspect it will die of old age eventually, hopefully not in the near future  :-) )