Where to start with my broken ST?

Problems with your machine in general.
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Badwolf
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Joined: Tue Nov 19, 2019 12:09 pm

Re: Where to start with my broken ST?

Post by Badwolf »

Nothing looks to be screamingly obviously wrong. The clips are still in place on the PLCCs. That's a good sign.

All the memory resistors looks to be in place.

The only thing that catches the eye is one of the pins on the centre PLCC (MMU?) looks odd. Could just be that white crayon used on the tops carried a little too far?

IMG_20220810_184141.jpg
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Next step would be power it back up (make sure the bottom's not shorted) and do the finger test on the RAM chips, as mentioned above.

If all else fails a copy of DiagROM/ST might be useful (the ROMs look socketed)? https://github.com/terriblefire/diagromst

BW
DFB1 Open source 50MHz 030 and TT-RAM accelerator for the Falcon
DSTB1 Open source 16Mhz 68k and AltRAM accelerator for the ST
Smalliermouse ST-optimised USB mouse adapter based on SmallyMouse2
FrontBench The Frontier: Elite 2 intro as a benchmark
aled
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Joined: Fri Aug 05, 2022 5:13 pm

Re: Where to start with my broken ST?

Post by aled »

That PLCC is OK as far as I can tell, just some of the white gunk (thermal compound? glue?)

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DiagROM looks useful, though I have no tools to burn ROM chips.

I will power up the machine and check the temperature of the RAM chips next.
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derkom
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Re: Where to start with my broken ST?

Post by derkom »

aled wrote: Wed Aug 10, 2022 5:50 pm OK, I worked it out eventually, need to shimmy the whole motherboard forwards to get the shield around the power switch.
For future reference, once you've removed the screws that secure the board onto the bottom case, you can remove the whole assembly as a unit, and then remove the top shielding and PSU after it's out of the case. Sometimes this makes things a bit easier.
aled
Posts: 9
Joined: Fri Aug 05, 2022 5:13 pm

Re: Where to start with my broken ST?

Post by aled »

Not keen on having 240v within touching distance, so tonight's job was to butcher an old ice cream tub to hold the PSU.

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