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Re: A500 - resurrection or pit of despair?
Posted: 13 Mar 2025 20:33
by JezC
Ok, so the last A500 fails to boot at the moment (seems to be about 10 short flashes on the power LED, then one longer Flash & the cycle repeats - provided I've counted that correctly :lol: :roll: )
That looks to be upgradeable from 512k to 1M on the motherboard so I will have to decide what to do if/when I manage to fix it.
That won't be happening tonight though. :(
Re: A500 - resurrection or pit of despair?
Posted: 13 Mar 2025 21:40
by exxos
What is it with you and motherboard problems :lol: :chairsmack:
Re: A500 - resurrection or pit of despair?
Posted: 13 Mar 2025 22:16
by rubber_jonnie
JezC wrote: 13 Mar 2025 20:33
Ok, so the last A500 fails to boot at the moment (seems to be about 10 short flashes on the power LED, then one longer Flash & the cycle repeats - provided I've counted that correctly :lol: :roll: )
That looks to be upgradeable from 512k to 1M on the motherboard so I will have to decide what to do if/when I manage to fix it.
That won't be happening tonight though. :(
Have you got the Amiga DiagROM? Might help
Re: A500 - resurrection or pit of despair?
Posted: 13 Mar 2025 23:59
by atari030
JezC wrote: 13 Mar 2025 20:33
Ok, so the last A500 fails to boot at the moment (seems to be about 10 short flashes on the power LED, then one longer Flash & the cycle repeats - provided I've counted that correctly :lol: :roll: )
That looks to be upgradeable from 512k to 1M on the motherboard so I will have to decide what to do if/when I manage to fix it.
That won't be happening tonight though. :(
I just fixed a pair last week and one was doing that. I can't recall which was which (too many 500's lately), one was rev 5 and one was rev 6. The rev 5 had faulty U25 and the Rev 6 had an 8371 installed, swapped for a 8375 and away it went. Pretty sure it was the Rev 6.
Re: A500 - resurrection or pit of despair?
Posted: 15 Mar 2025 13:14
by JezC
exxos wrote: 13 Mar 2025 21:40
What is it with you and motherboard problems :lol: :chairsmack:
I'm learning from the best (that's you
@exxos :lol: :roll: ) plus a few other forum members...
Re: A500 - resurrection or pit of despair?
Posted: 15 Mar 2025 13:18
by JezC
rubber_jonnie wrote: 13 Mar 2025 22:16
JezC wrote: 13 Mar 2025 20:33
Ok, so the last A500 fails to boot at the moment (seems to be about 10 short flashes on the power LED, then one longer Flash & the cycle repeats - provided I've counted that correctly :lol: :roll: )
That looks to be upgradeable from 512k to 1M on the motherboard so I will have to decide what to do if/when I manage to fix it.
That won't be happening tonight though. :(
Have you got the Amiga DiagROM? Might help
Not for the A500, just the ST version.
No suitable EPROMs for the A500 as far as I know, just 256k & 512k bit EPROMs...27c256. & 27c512
:(
Re: A500 - resurrection or pit of despair?
Posted: 15 Mar 2025 13:21
by JezC
atari030 wrote: 13 Mar 2025 23:59
JezC wrote: 13 Mar 2025 20:33
Ok, so the last A500 fails to boot at the moment (seems to be about 10 short flashes on the power LED, then one longer Flash & the cycle repeats - provided I've counted that correctly :lol: :roll: )
That looks to be upgradeable from 512k to 1M on the motherboard so I will have to decide what to do if/when I manage to fix it.
That won't be happening tonight though. :(
I just fixed a pair last week and one was doing that. I can't recall which was which (too many 500's lately), one was rev 5 and one was rev 6. The rev 5 had faulty U25 and the Rev 6 had an 8371 installed, swapped for a 8375 and away it went. Pretty sure it was the Rev 6.
I'll check what that code indicates and look around those ICs as a starter - thanks!
Re: A500 - resurrection or pit of despair?
Posted: 15 Mar 2025 14:55
by rubber_jonnie
JezC wrote: 15 Mar 2025 13:18
rubber_jonnie wrote: 13 Mar 2025 22:16
Have you got the Amiga DiagROM? Might help
Not for the A500, just the ST version.
No suitable EPROMs for the A500 as far as I know, just 256k & 512k bit EPROMs...27c256. & 27c512
:(
I use a BooBip 27C400 emulator, they are great and easily programmed. Not sure if they are still available.
Re: A500 - resurrection or pit of despair?
Posted: 15 Mar 2025 15:09
by JezC
They were out of stock when I last looked...
Re: A500 - resurrection or pit of despair?
Posted: 15 Mar 2025 15:13
by rubber_jonnie
JezC wrote: 15 Mar 2025 15:09
They were out of stock when I last looked...
Ahh, rubbish...