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Opus Discovery "the big switch on" (after 20 years)I have a few of these Opus Discovery's with different Eproms in that have not been swiched for 15-20 years or so . I am in no rush to switch any on …
... either a rom or the lower ram gone and the floppy upgrade ... -3 with duel 720k drives, ram and rom
the ... -
Issue 3b boarddiode ID5 and cap C47 are missing from my board will these have any effect on system powering up. I have checked the voltages on the 7508 and its …
... measure the resistance of each RAM IC (you'll need to ... this for the upper and lower RAM chips. If all are ok ... -
Issue 3b boarddiode ID5 and cap C47 are missing from my board will these have any effect on system powering up. I have checked the voltages on the 7508 and its …
... feeling its one of the lower ram chips that is faulty, I ... -
Harlequin Rev GI have just got all the bits to build an Harlequin Rev G system and I went for a red solder mask board. I have fitted the 3 surface mount components…
... the SRAM that forms the "lower" RAM (where the video screen is ... -
Harlequin Rev GI have just got all the bits to build an Harlequin Rev G system and I went for a red solder mask board. I have fitted the 3 surface mount components…
... the SRAM that forms the "lower" RAM (where the video screen is ... -
12V ripple with lower ram installedI repaired a speccy this week. Before doing anything I replaced all caps and measured the transistors in the power section. When doing this I found t…
... this with and without the lower ram installed, same results. Does this ... -
12V ripple with lower ram installedI repaired a speccy this week. Before doing anything I replaced all caps and measured the transistors in the power section. When doing this I found t…
... +12v decoupling capacitors for the lower RAM. These are only 47nf so ... -
12V ripple with lower ram installedI repaired a speccy this week. Before doing anything I replaced all caps and measured the transistors in the power section. When doing this I found t…
... do some changing of the lower ram ic's, it was really ... faulty one, since I got ram error's but it wasn ... -
Issue 4A, tests complete fine but get odd crashing problemHi all, I've got an issue 4A which has had all of its lower RAM replaced, TR4, TR5 as well as its CPU. It originally had quite high voltages (20-3…
... all the joints on the lower RAM, CPU and caps (I recappped ... whether it was after the RAM and TR4/TR5 was replaced ... or not. My own RAM is clearly a bit lacking ... an error. I ran the RAM test again after Manic Miner ... -
48k Speccy died, resistors getting too hot to touchHi folks, With 2 days to go till an exhibition my trusty dual-boot 48K issue 3b that I made last year has given up the ghost and I'm not sure I ha…
Check voltages on the lower RAM - I'd wager that -5v and +12v are missing, caused by a shot TR4/TR5.
B -
48k Speccy died, resistors getting too hot to touchHi folks, With 2 days to go till an exhibition my trusty dual-boot 48K issue 3b that I made last year has given up the ghost and I'm not sure I ha…
... took out voltage to the lower RAM which made me think my ... -
48K Issue 6a wobbly and flickering TV outputHi folks, Found an untested issue 6A Spec whilst tidying up and it had a warranty sticker on it from a past repair which seemed to be a socketed L…
... 've fixed today (keyboard membranes, lower RAM, one coil) this is the ... -
Need some help repairing an issue 3 spectrumI am looking for some help repairing an issue 3 speccy, here's what I tried so far. The speccy is not booting up correctly, when using the diagnos…
Yep, as Mark says, check the voltages first. If they're not as expected, don't run the machine longer than is absolutely necessary as the lower RAM may become further damaged.
B -
Need some help repairing an issue 3 spectrumI am looking for some help repairing an issue 3 speccy, here's what I tried so far. The speccy is not booting up correctly, when using the diagnos…
... cartridge is connected, just the lower ram always tests faulty. -
Need some help repairing an issue 3 spectrumI am looking for some help repairing an issue 3 speccy, here's what I tried so far. The speccy is not booting up correctly, when using the diagnos…
Actually with the lower ram removed the picture should be different, without the pauses.
https://www.youtube.com/watch?v=_v4NZGE_4hU
It's like this on my other spectrum. -
Need some help repairing an issue 3 spectrumI am looking for some help repairing an issue 3 speccy, here's what I tried so far. The speccy is not booting up correctly, when using the diagnos…
... ="patzik;873311"]Actually with the lower ram removed the picture should be ... you'd expect if all RAM was removed would indicate to ... -
Need some help repairing an issue 3 spectrumI am looking for some help repairing an issue 3 speccy, here's what I tried so far. The speccy is not booting up correctly, when using the diagnos…
... spectrum I tried without the lower ram. This video is exactly the ... you said.
With the lower ram installed all ic's test ... adressing, I'll reinstall the lower ram and do some more testing. -
Need some help repairing an issue 3 spectrumI am looking for some help repairing an issue 3 speccy, here's what I tried so far. The speccy is not booting up correctly, when using the diagnos…
... spectrum I tried without the lower ram. This video is exactly the ... you said.
With the lower ram installed all ic's test ... adressing, I'll reinstall the lower ram and do some more testing ... -
Magenta border and black screenGot my hands on a issue 3 48k machine. Did the initial resistance checks and everything seemed in order buy when I switch the machine on all I get is…
Also make sure you're getting the right voltages in the lower RAM.
B -
what are the differences between the 48K spectrum and the spectrum+ ?^^^^^ see above ^^^^^
... 't bloody remember!
Probably lower RAM and the power supply switching ... -
Magenta border and black screenGot my hands on a issue 3 48k machine. Did the initial resistance checks and everything seemed in order buy when I switch the machine on all I get is…
... have ordered one of zorns lower ram replacement modules so will see ... -
Magenta border and black screenGot my hands on a issue 3 48k machine. Did the initial resistance checks and everything seemed in order buy when I switch the machine on all I get is…
... have ordered one of zorns lower ram replacement modules so will give ... -
ZX Spectrum issue 4B acquiredI recently acquired a ZX Spectrum with serial number 138-363292 on the case, and a 1983 issue 4B board I got it for the purpose of repair. and have…
... like there may be damaged lower ram (seems 2 may have been ... -
Spectrum 48+ 4S - Upper RAM issue, and now a self-created problem!I recently picked up a known-flaky spectrum off eBay, to have a bit of fun fixing it and reliving youth. It was labelled as 'keyboard duff, shows…
... . You could try changing the RAM type selection links. Suggest the ... final thought, the 16k of lower RAM is only refreshed by the ... -
help with my original issue 3b from when i was a teen. possible lower ram fault.hello, well ive tried to fix my old speccy, but haven't made much progress. could you help me out with some diagnosis. the fault occurred about…
ive been told it cold be the rom or cpu. as generally lower ram faults result in vertical lines and not able to type anything. -
help with my original issue 3b from when i was a teen. possible lower ram fault.hello, well ive tried to fix my old speccy, but haven't made much progress. could you help me out with some diagnosis. the fault occurred about…
just a thought. what if I remove some of the lower ram ics. would it maybe clear the screen. that would defo mean lower ram fault. -
help with my original issue 3b from when i was a teen. possible lower ram fault.hello, well ive tried to fix my old speccy, but haven't made much progress. could you help me out with some diagnosis. the fault occurred about…
... % okay.
All the RAM chips are DRAM type. In ... of every byte of the lower RAM working. It will not then ... variations of symptoms of a RAM fault. The problem with your ... may not be a RAM fault. But RAM faults and faults with ... -
help with my original issue 3b from when i was a teen. possible lower ram fault.hello, well ive tried to fix my old speccy, but haven't made much progress. could you help me out with some diagnosis. the fault occurred about…
I think ill buy some lower ram ics.
yes ive got a multimeter. I checked the voltages and they seem about right. ive recapped it when I removed the upper ram.
I might buy a spare rom just incase. -
can a backup device damage the spectrum ROM?as above. been using a specmate device which seems to have corrupted my speccys ROM.
... work fine), the other the lower RAM.
