1040STe locks up or bombs out after warming up

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Todd
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1040STe locks up or bombs out after warming up

Post by Todd » Mon May 14, 2018 12:03 am

Hi Folks! I'm having some troubles with my 1040STe.

I picked this machine up a couple years ago from the UK. I replaced the PSU with a 110v psu so I wouldn't have to use a step up transformer to power it.

Problem is this: Once first powered on everything generally works fine. After about 15 to 25 minutes I start getting lock ups. The unit will just freeze or I will typically get 3 bombs. If I power it off for quite a while it will continue to work again.

So far I have tried 2 different PSUs in it. Including a Picopsu mod. Both exhibit the same behavior. So I don't think it's PSU related.

The machine has 4 megabytes ram and only mod to it has been that I replaced the floppy drive with a Gotek floppy emulator. Running the latest HxC firmware. No external HD or other mass media. I use a PS/2 to Atari mouse interface so that I can use a regular PS/2 mouse. TOS 1.62

I have pulled and reseated several IC's on the board, though I haven't done them all yet. It appears to me that something is overheating, however with the occasional 3 bombs I am not sure.

I have also ran the machine without the top of the case on it and the lockups still occur.

Could this be signs of a bad cpu? Perhaps some other component is heating up and causing the fault?

I have owned several STe machines over the years and haven't seen this kind of behavior before.


Thanks!

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exxos
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Re: 1040STe locks up or bombs out after warming up

Post by exxos » Mon May 14, 2018 10:20 am

You need to recap your PSU.. pico's a lot of them are worse than a failing Atari PSU.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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rubber_jonnie
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Re: 1040STe locks up or bombs out after warming up

Post by rubber_jonnie » Mon May 14, 2018 11:30 am

exxos wrote:
Mon May 14, 2018 10:20 am
You need to recap your PSU.. pico's a lot of them are worse than a failing Atari PSU.
Definitely do the above first. Or try a different genuine Atari PSU if you have one available. As exxos says, Picos are not ideal.

Also, have you tried a different set of SIMMS? or Cleaned the contacts on the SIMMS with IPA?

By removing the top of the case, do you mean plastic case or steel shroud? or both? Airflow in ST/STF/STFM & STEs relies on the hot air rising, and this causes a flow through the system, but it's not great, so any component that is overheating is likely to suffer with the casework on.
Collector of old Atari things:
800XL + Ape Warp mod, 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, 2600jr, 7800 and Lynx II
Atari 520ST + Gotek, 1040STF, 4160STE with 32Mhz booster, ROM switcher and CosmosEx
Plus the rest..
C64 + 1541 and cassette, 2x Sinclair QL, Mac Classic, Mac Performa 6200, Amiga 1200, ICL One Per Desk, Epson HX20, Dreamcast, original Xbox, SNES and a bunch of other bits n bobs I can't remember right now. :D
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Todd
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Re: 1040STe locks up or bombs out after warming up

Post by Todd » Mon May 14, 2018 11:50 am

rubber_jonnie wrote:
Mon May 14, 2018 11:30 am
exxos wrote:
Mon May 14, 2018 10:20 am
You need to recap your PSU.. pico's a lot of them are worse than a failing Atari PSU.
Definitely do the above first. Or try a different genuine Atari PSU if you have one available. As exxos says, Picos are not ideal.

Also, have you tried a different set of SIMMS? or Cleaned the contacts on the SIMMS with IPA?

By removing the top of the case, do you mean plastic case or steel shroud? or both? Airflow in ST/STF/STFM & STEs relies on the hot air rising, and this causes a flow through the system, but it's not great, so any component that is overheating is likely to suffer with the casework on.
Actually my Atari psu has been recapped. I forgot to mention that.

And by top off, I do mean both the plastic and the metal RF shield both off.

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exxos
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Re: 1040STe locks up or bombs out after warming up

Post by exxos » Mon May 14, 2018 11:57 am

Did you recap with one of my kits or some other brands of caps ? Checked for bad joints all over the board ? new switch ?

I would run this program and leave it on for a few hours and see what happens..viewtopic.php?f=25&t=28
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

troed
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Re: 1040STe locks up or bombs out after warming up

Post by troed » Mon May 14, 2018 2:28 pm

I'd try hunting for an unusually hot IC, wrong resistance on a bus (adress or data) ... the alternative might be hairline cracks somewhere ...

(I have a MegaSTE where it seems the DMA bus goes wonky after 10-15 minutes .. so maybe something similar. There I'm thinking of adding resistance to the pullups)

/Troed

Todd
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Re: 1040STe locks up or bombs out after warming up

Post by Todd » Tue May 15, 2018 4:10 pm

Took the plastic case top off my STe, removed the RF shield and left the keyboard outside the case for maximum ventilation.
Airconditioning was running and the ambient room temp was about 74f/23c.

Ran a few demos and didn't see any crashing.



Ran YAART overnight. Completed 48 passes with zero errors before the machine bombed out with 11 bombs.


Image

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exxos
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Re: 1040STe locks up or bombs out after warming up

Post by exxos » Tue May 15, 2018 4:15 pm

I would suggest trying the HC type CPU and see if that helps..

As troed said also, you may need to change the SIL resistors.. what values are on the address and databus on your machine ? (they are located around the CPU & blitter ). All the red ones like on this image.. viewtopic.php?f=51&t=783#p5568
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

Todd
Posts: 6
Joined: Sun May 13, 2018 11:34 pm

Re: 1040STe locks up or bombs out after warming up

Post by Todd » Tue May 15, 2018 4:20 pm

exxos wrote:
Tue May 15, 2018 4:15 pm
I would suggest trying the HC type CPU and see if that helps..

As troed said also, you may need to change the SIL resistors.. what values are on the address and databus on your machine ? (they are located around the CPU & blitter ). All the red ones like on this image.. viewtopic.php?f=51&t=783#p5568
I will look into this info and report back.

Todd
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Joined: Sun May 13, 2018 11:34 pm

Re: 1040STe locks up or bombs out after warming up

Post by Todd » Wed May 16, 2018 1:21 am

Couple pics of the area around the cpu and blitter.


Image
Image

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