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Short Circuit Damage?Hey Spectrum fans, Currently trying to diagnose what is wrong with my 48K Issue 4B ZX Spectrum. The initial problem was the fact it would not boot -…
... a fault in the lower 16K of RAM. Well, that was the ... problem. Since all the lower IC ... -
Spectrum 48k ProblemsHi all Got my 48k today but it's playing up abit... First time i turn it on it was like this: [IMG]http://s26.postimg.org/hlg9d3f3d/IMG_20140830_…
... mean? I'm guessing the lower RAM is not very well? :-( -
48k - Why Won't it Buzzzz?Hi WOS ;) I bought a load of Spectrum games off eBay and thrown in for good measure was a 48k 1984 Issue 6a circuit board that I was told was for sp…
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The voltages around the lower RAM ICs are all wrong however ... what appears I know the lower RAM is faulty (alternating black & ... all work fine. The upper RAM has been removed and donated ... -
Issue 6 repair with a twist...(Starting with a slight grump - the forum ate my first attempt at this so this'll probably end up being a bit terse :)) I got a Issue 6 48K machine …
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I suspected faulty upper RAM trashing the stack, and this ... diags were reporting both lower and upper RAM were healthy.
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Now suspecting a lower RAM issue, I entered and ran ... then reinitialised, and the RAM being tested is compared against ... -
Help with 128k greyHello friends, need some help here on try fixing a +2 grey spectrum128. To keep it short, opened the case and the voltage regulator was missing, the …
... point I desoldered all the ram chips and after testing 4 ... with ramtest eprom fitted and... "lower" ram test passed. Then an error ... an ic 22 failure (uncontended ram) but I'm sure it ... is not the ram chip. Checked the socket and ... -
Issue 1 oddityHello to everybody, I have a very first under my hands - a broken Issue 1. Apart from the classic "broken lower RAM" syndrome which will be easily t…
... . Apart from the classic "broken lower RAM" syndrome which will be easily ... blue. Even Paul Farrow's RAM tester shows its white bars ... -
Smokin... more 48k woesHi, it looks like I've converted another Spectrum 48K+ into a smoke machine. I'd been rebuilding an Opus Discovery unit and everything looked good. …
... ; ICs I noticed that the RAM? (smallest socketed) IC on the ... ver.4S motherboard with Zorns lower RAM module and a composite mod ... -
Issue 2 Spectrum - Black screenHi I have an issue 2 spectrum which I'm having some issues with. I bought it on ebay so have no idea of the history or how it came to be broken. Whe…
... out that one of the lower RAM chips was faulty. I ... pin 2 of the lower RAM and found 1 that ... get the corresponding upper RAM location and sure enough ... I replaced the offending upper RAM chip but it made ... swapped some of the lower RAM chips about to different ... -
I broke my 48k Speccy!!!!Hey guys, I am looking for some advice, I hope you can point me in the right direction. So, I went about replacing all the capacitors on my issue 4…
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The voltages on the lower ram are well out of whack ... now have issues with my lower ram now due to the weird ... -
Double keystrokes on zx spectrumHappy New Year everyone. I have this spectrum 48k issue 3b I?ve been working on now and then. I have replaced upper rams, installed a lower ram repla…
... replaced upper rams, installed a lower ram replacement module and it starts ... -
48K Not booting properlyBought another faulty spectrum from Ebay. This one, when you turn it on, it looks like it's going to boot OK, but when it gets to the point where it…
... found I had a faulty Lower RAM IC (IC 6) and replaced ... -
48k issue 2 video issueHi folks. I am currently tring to fix an issue 2 board. I was getting the yellow greenish screen. (also there there is a lower ram fault with it i th…
... . (also there there is a lower ram fault with it i think ... -
Joytsick Interface damaged SpectrumHello All, Sob.. I am a plonker, I did the cardinal sin, I was testing a bunch of joystick interfaces that I got off ebay and one didn't have the ke…
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The voltages on the lower RAM are not correct, it appears ... +12v. Does this mean the lower DRAM is now toast?
Finally got round to itFinally got round to giving my old speccy a close look. Details 1982 Issue 2 Seriel No 001 196193 Hmm... Followed the initial tests on You tube w…
... a fail then
Lower ram tested on 200Kohm range
Upper ram socketed
Any comments ...TR4/TR5 replacementHi guys, I've got another Spectrum I'm working on now - an Issue 4S this time. When I originally got it, I powered it up and did the basic tests a…
... with the upper 32K of RAM. Not surprising, and I've ... ]. Testing the voltages on the lower RAM IC's show they are ... are still wrong on the lower RAM IC's, so I'm ...not working issue 3Hi all, I received this mobo from ebay, after start i have this on screen [img]http://forest.no-ip.org/wos/issue3_01/20150728_135908.jpg[/img] …
... 't have and -5v on lower ram, have only 5v.
I ...ZX Spectrum issue 2 has only blue tintsRecently I've bought a 16k speccy and ran into some issues with it. Faulty keyboard, broken caps, no stable frequency, faulty lower RAM chip, it bein…
... caps, no stable frequency, faulty lower RAM chip, it being 16k, the ... but hey), switched out the lower RAM for a modern solution and ... modern 32k ram upgrade installed.
Now ...Not bored with the Boards.Going through some old tapes stored rather badly I came across an unlikely item that that I must have stored away quickly with other low grade items …
... depopulated , with 4 of the lower ram chips missing , the video modulator ...Weird crashing problemOK, got an odd (to me anyway!) problem. 16k Spectrum, appears to work fine, it starts up, go to load a game (Trans Am, Cookie, Jetpac etc), the game …
... up at all if the lower RAM was faulty?
Thanks ...12V Rail - Spectrum 48kOkay - I may just be having a senior moment here, but I'm running out of ideas. I'm working on a Spectrum Issue 4S board,and have had to remove al…
... to remove all the 16k RAM chips and work on the ... re-capped throughout, replaced the RAM with sockets, replaced TR4 and ... a problem. Before fitting new RAM, I checked the voltages, and ... 2 board here with no lower RAM, and the rail there was ...Faulty Issue 1Hi all, thought I'd document my efforts in getting another speccy working. I've never done this before so please bear with me... I recently took a p…
... speccy, dead cockroach with 32K Ram pack installed. Lo and behold ... 7805 and the left-most lower RAM chip getting red hot. I ... off promptly and snip all lower RAM chips supply legs. Switch back ... need to put some good lower RAM in? If so, I could ...Issue 3B woesHello there, I currently have a Issue 3B for repairs around, it used to have broken upper and lower RAM, which I replaced with 41256-120 DRAMs (hac…
... to have broken upper and lower RAM, which I replaced with 41256 ...Testing 4116 type DRAMsHappy New year All! I'm managed to find some time to repair some more Spectrums :) woo hoo. I have a couple with busted lower RAM, Sooo, I appr…
... have a couple with busted lower RAM, Sooo, I appreciate I could ... buy a swanky ZX Spectrum Lower RAM Replacement Module, but I think ... feasible to actually make a ram module replacement with ease?Unresponsive Spectrum with Magenta border.This Spectrum is taking an age for me to repair, thank for all the help thus far! So after I switch on the ZX Spectrum+ I get the familiar white…
... Spectrum that I destroyed the lower RAM via a dodgy joystick interface ... , so far I replaced the lower RAM with one of these http ...Bizarre ZX Spectrum faults (also possibly relevant to Spectranet compatibility problems).I'm attempting to repair an issue 4A 48K ZX Spectrum and am encountering some very strange problems. For my own records I've given this computer the …
... corruption of the contents of lower RAM. A few errant pixels and ... reported finding a RAM fault while testing lower or upper RAM.
< ... or SRAM module for the lower RAM and a different ROM ( ... when the original OKI upper RAM is fitted.
- Spectranet: ...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 …
... 7508 and its good, the ram chips have +12, +5 and ... now sure its a bad lower ram chip unless the above components ...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…
... has had all of its lower RAM replaced, TR4, TR5 as ... and some very questionable RAM. TR4 and TR5 were ... replaced and with new RAM it appeared a lot ... 've tried swapping the RAM chips around and have ... difference. The voltages on the RAM appears fine.
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…
... least a pair of 4116 lower RAM chips. TV output was dodgy ...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…
... using the diagnostic rom all lower ram ic's fail, the ic ... installed.
Removed all lower ram, and turned the spectrum on ... it works expect for the lower ram.Upper memory issueZX Spectrum 48K, issue 2, boots fine. Lower RAM OK. When tested with the new test ROM in the Diagboard, for all upper RAM tests "FAIL" is shown. I…
... , issue 2, boots fine.
Lower RAM OK.
When tested with ... the Diagboard, for all upper RAM tests "FAIL" is shown.
lower RAM, are the voltages:
4116 ...
