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A500 - resurrection or pit of despair?

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JezC
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Re: A500 - resurrection or pit of despair?

Post 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. :(
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exxos
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Re: A500 - resurrection or pit of despair?

Post by exxos »

What is it with you and motherboard problems :lol: :chairsmack:
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rubber_jonnie
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Re: A500 - resurrection or pit of despair?

Post by rubber_jonnie »

JezC wrote: Thu Mar 13, 2025 8:33 pm 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
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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atari030
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Re: A500 - resurrection or pit of despair?

Post by atari030 »

JezC wrote: Thu Mar 13, 2025 8:33 pm 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.
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JezC
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Re: A500 - resurrection or pit of despair?

Post by JezC »

exxos wrote: Thu Mar 13, 2025 9:40 pm 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...
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JezC
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Re: A500 - resurrection or pit of despair?

Post by JezC »

rubber_jonnie wrote: Thu Mar 13, 2025 10:16 pm
JezC wrote: Thu Mar 13, 2025 8:33 pm 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

:(
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JezC
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Re: A500 - resurrection or pit of despair?

Post by JezC »

atari030 wrote: Thu Mar 13, 2025 11:59 pm
JezC wrote: Thu Mar 13, 2025 8:33 pm 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!
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rubber_jonnie
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Re: A500 - resurrection or pit of despair?

Post by rubber_jonnie »

JezC wrote: Sat Mar 15, 2025 1:18 pm
rubber_jonnie wrote: Thu Mar 13, 2025 10:16 pm

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.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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JezC
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Joined: Mon Aug 28, 2017 11:44 pm

Re: A500 - resurrection or pit of despair?

Post by JezC »

They were out of stock when I last looked...
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rubber_jonnie
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Re: A500 - resurrection or pit of despair?

Post by rubber_jonnie »

JezC wrote: Sat Mar 15, 2025 3:09 pm They were out of stock when I last looked...
Ahh, rubbish...
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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