Author Topic: Dead Acorn A3010  (Read 1021 times)

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Offline angust_uk

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Dead Acorn A3010
« on: September 11, 2017, 11:51:34 am »
Hi all

I dusted off my old A3010 recently for a bit of nostalgia, and found that it now refuses to boot. No floppy initialisation (or floppy LED flashes), speaker sound or video output. I changed the battery a while ago (thankfully there wasn't too much corrosion on the PCB), and have checked all the oscillators I can find as well as for stable power rails. All fine, but still no joy at all. Not sure what to try next - is there any way to check to see if the CPU is running? (it gets warm to the touch, so it's doing something at least!).

The usual reset procedures (e.g. holding delete whilst booting) don't do anything as far as I can tell.

Any input gratefully received (this was my first 'proper' computer and there are a lot of my old BASIC programs I'd love to have a look at again!)


Angus
 

Offline bd139

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Re: Dead Acorn A3010
« Reply #1 on: September 11, 2017, 01:02:32 pm »
Try reseating the OS ROMs. They get a bit funky with age.

As for seeing if it's running or not, you would need a logic probe or scope and poke around the address bus on the ARM CPU.
 
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Offline stj

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Re: Dead Acorn A3010
« Reply #2 on: September 11, 2017, 03:57:53 pm »
it probably uses a small electrolytic to generate the reset pulse when the power is connected.
 
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Offline philpem

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Re: Dead Acorn A3010
« Reply #3 on: September 13, 2017, 12:15:22 pm »
Did you wash the board around the battery with white vinegar or similar (and a second wash with distilled water) to neutralise the battery electrolyte?

If not, a bit of the electrolyte might have leaked into the tracking...

The machine blinks out an error code on the floppy LED if it fails POST. What's the error code? (if I remember rightly, it's 32 bits blinked in groups of four bits, long is a '1' and short is a '0', with a long gap at the end before it repeats)


EDIT - oops just noticed you're not getting the blinks. Check the power rails (they're clearly marked in the power supply area). Probably a dud or weak voltage regulator or a fried capacitor. I seem to recall these machines (unlike the A3000) run a linear power supply which is built onto the motherboard.
Phil / M0OFX -- Electronics/Software Engineer
"Why do I have a room full of test gear? Why, it saves on the heating bill!"
 
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