Uh Oh.Electron inbound

Any 8bit repairs, images, cool things, upgrades etc.
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rubber_jonnie
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Re: Uh Oh.Electron inbound

Post by rubber_jonnie » Wed Jun 09, 2021 2:28 pm

stephen_usher wrote:
Wed Jun 09, 2021 2:19 pm
I'd have thought that you'd have a 470uF in stock as they're so ubiquitous.
I do, but like many, many other things at the moment, they are in a box, and in storage due to the house move, hence having to order some.

To be fair, I need axial and the ones I have in storage are not, though it hasn't stopped me before.
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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rubber_jonnie
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Re: Uh Oh.Electron inbound

Post by rubber_jonnie » Wed Jun 09, 2021 8:51 pm

And here's the keyboard and top case after a wash:

Cleaned_Up.jpg
Cleaned_Up.jpg (96.15 KiB) Viewed 1004 times

The colour is really quite good, and I'm looking forward to getting the power board sorted so I can test if it powers up ok.

There's the usual UHF, Composite & RGB out, so although I can't test the composite, as the model B uses a BNC connector and I don't have an adaptor for the phono of the Elk to BNC, the RGB SCART lead for the Beeb should work just fine.

Already eyeing up the ELK64SD adaptor for extra RAM/ROM space and SD card for disk images.
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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arkadiusz.makarenko
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Re: Uh Oh.Electron inbound

Post by arkadiusz.makarenko » Wed Jun 09, 2021 10:27 pm

For some reason I went more traditional path, and I have Plus 1 and Pegasus 400 floppy interface, but to be honest Mega Game Cartridge does equally great job.
Do not trust people. They are capable of greatness.
~ Stanislaw Lem

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rubber_jonnie
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Re: Uh Oh.Electron inbound

Post by rubber_jonnie » Wed Jun 09, 2021 10:45 pm

arkadiusz.makarenko wrote:
Wed Jun 09, 2021 10:27 pm
For some reason I went more traditional path, and I have Plus 1 and Pegasus 400 floppy interface, but to be honest Mega Game Cartridge does equally great job.
Interesting, I'll look that one up, but think the Elk cart will be the one I go for. It is sometimes nice to have the original floppies, which I do for my A8s and C64.

Somehow since I moved into this rental, I've acquired 2 BBC Bs, the Electron and an Amstrad NC100. I'd better stop for a bit so we can move into the new house and I can get my workshop and retro room set up!!
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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rubber_jonnie
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Re: Uh Oh.Electron inbound

Post by rubber_jonnie » Fri Jun 11, 2021 1:09 pm

Ok, so good news/bad news on the Electron Front.

The caps arrived and I now have good power, however it's not all roses.

The screen looks like this:

Stripey.jpeg
Stripey.jpeg (57.04 KiB) Viewed 960 times

So more troubleshooting required, but it's a start, because it shows me that the video circuit is working, and it's also likely the CPU is good too, and a quick check shows me that the clocks seem good too.

So at this point I'm thinking RAM, but can't discount ROM or possibly the ULA.

I think RAM at this point unless anybody has any other thoughts?
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

stephen_usher
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Re: Uh Oh.Electron inbound

Post by stephen_usher » Fri Jun 11, 2021 1:46 pm

Well, RAM is the most common thing to fail, so out with the toy scope and look at the data pins on the RAM chips!
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.

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Re: Uh Oh.Electron inbound

Post by rubber_jonnie » Fri Jun 11, 2021 1:54 pm

stephen_usher wrote:
Fri Jun 11, 2021 1:46 pm
Well, RAM is the most common thing to fail, so out with the toy scope and look at the data pins on the RAM chips!
Lol, must have read my mind:)

I've broken out the frequency counter and I have 16Mhz at pin 49 of the ULA, and 1Mhz at the 3 clock pins, so in and out, on the CPU. /RESET is high at the CPU too. Since I'm getting a signal on screen, I have to think that the ULA is ok, and it's trying to run, but it's crashing because of the RAM being bad.

Scope will be next, but have to do some work first.
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

stephen_usher
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Location: Oxford, UK.
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Re: Uh Oh.Electron inbound

Post by stephen_usher » Fri Jun 11, 2021 1:55 pm

But... "work" is a four letter word! (But so is "play". ;-) )
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.

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rubber_jonnie
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Re: Uh Oh.Electron inbound

Post by rubber_jonnie » Fri Jun 11, 2021 2:25 pm

stephen_usher wrote:
Fri Jun 11, 2021 1:55 pm
But... "work" is a four letter word! (But so is "play". ;-) )
I know, but I have a new house to pay for!
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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rubber_jonnie
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Re: Uh Oh.Electron inbound

Post by rubber_jonnie » Fri Jun 11, 2021 3:52 pm

Ok, so the service manual suggests that DRAM is the problem, based on the diagnostic chart found on page 20, which fits with what I'm seeing on screen and the other diags I've done.

So, new RAM is ordered, my major annoyance now is actually determining which RAM chip, or chips, is the culprit, since the service manual doesn't give any hints and just says 'Faulty DRAM or broken track; replace.

I know there are only 4 chips, but I'd rather not kill any good ones if I can avoid it.
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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