ZX Spectrum Marketplace Gamble - Issue 3B Repair and Service
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- เผยแพร่เมื่อ 26 ส.ค. 2024
- I love picking up broken machines to rescue, this came from Facebook Marketplace, hopefully it's going to be a good purchase, let's see!
If you enjoyed this then check out:
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Repair work - happylittledio...
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Woww, glad you are back making videos.
Great video. Nice to see you back.
Thanks John!
Great video, keep them coming!
Another one saved, nice work! Talking of unnecessary desoldering… I recently replaced the RAM in my +3 because I was absolutely convinced it had a memory fault (I agree, it's not easy to resist the temptation to lever the chips out - but like you say you just have to take your time and go pin-by-pin carefully) but after all that effort-and wasted time-it turned out it was just the CPU at fault after all! Yes, the socketed, easy-to-replace Z80 CPU!! Oh well…!
C'est la vie! I've been in that situation and it turned out to actually be memory, just took the removal of many chips
From my experience there is a few things you should be doing generally: 1) Use of a static strap and do try and avoid touching pins if you can 2) Cut joints before soldering because cutting after can stress the joints 3) clean of flux after soldering. I know that none of these are deal breakers, but they are good practice.
All good tips thanks, you're absolutely right
Always a pleasure to watch your videos Mr Diodes!
Thanks so much Mr It!
Yay, new Happy Little Diodes vid!
cool music
Nice repair.
I have a video testing chips on a diagnostic card do you have any dodgy z80, ula or ram multiplexor chips you don't want ?
Hi Lee. I have a pile of them, what do you need? I'm interested in what you're planning to do with knackered chips!
@@HappyLittleDiodes nothing special, I have a diagnostic card with the leds that can show some faults the 0.38 does not show and I made a video recently testing it out with some chips I have and I am about to release a 2nd with some more so just looking for chips I can continue the testing.
@@HappyLittleDiodes If you have any 74ls157 or 74ls32 from the ram multiplexer circuits I have not tested those yet. Or anything that you think could be interesting to test and probe.
I might have some 157's in the graveyard, I'll check later after work
Nice video. I am curious though why you did not swap the regulator for a new cooler one?
I could have, but the temperatures involved are all within spec and with the heatsink on a stable ULA I decided to keep the original warmth and weight. They are about 6 quid each too and this had already consumed a pricey ULA
As a ULA is a custom Logic Chip, might it be possible to revive some faulty ULAs (depending in the fault) by installing external logic chips? Sinclair did similar things with the dead bug mod. I've seen that modern replacement ULAs are very expensive and in short supply.
Sure, in theory you could externalize the circuit when you have a deaf or mute ULA ... not exactly worth the effort tho since chances are high it will fail more severely sooner or later. Especially when data bits are dead things will get quite complex quickly and signal runtimes might become an issue.
Best bets would be either replacements or going with a Harlequin Spectrum. Might be possible to design a "drop in ULA board" based on TTL logic chips which can still be easily obtained BUT that will easily go over the space limit a rubber Spectrum has left.
If you're going this far you might consider looking at one of the clone boards (e.g. Pentagon) that have constructed the ULA using multiple smaller chips
What double sided tape do you use? I've got one here that ive tried to stick down 3 times now and its not having it!
From RS.
3M 9088 Transparent Double Sided Plastic Tape, 9mm x 50m
Stock no.:503-4834
@@HappyLittleDiodes Discontinued apparently but that gives me an idea on what to look for ! Cheers :)
5:30 what do you use to clean edge connector?
A fibreglass pen and I normally use alcoholic spirit and a toothbrush after before a wipe with a cloth
@@HappyLittleDiodes What about using a pencil eraser instead? Fibreglass pens are quite unpleasant to work with and one needs to be careful not to overdo the job. Added bonus: results look way more even.
The best game is pitman 7
Hay, welcome back mate! Thought the repair of my Speccy had done you in and you'd scrapped it all lol. Good to see you back.
Thanks Jay!