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Broken or upgraded ZX Spectrum 48kHello First i want to say hello to everybody. I have a new ZX Spectrum 48k in my collection. Seller said that it is broken (no picture). I have this…
... sense when voltages are [I]missing[/I], as opposed to close ... [/I] diodes! Also see the voltage rating on it - diodes don ... -
Spectrum +2a / +3 SCART LeadsEvening all, Over the past week or so I've tried two different Spectrum RGB SCART leads from two different Ebay sellers, on a Spectrum+2A and a Spec…
... -speed (hence low impedance, low voltage) switching between RGB & composite ... up to 12V input voltage. If this is missing, sometimes you see ... -
Spectrum +2a / +3 SCART LeadsEvening all, Over the past week or so I've tried two different Spectrum RGB SCART leads from two different Ebay sellers, on a Spectrum+2A and a Spec…
... -speed (hence low impedance, low voltage) switching between RGB & composite ... up to 12V input voltage. If this is missing, sometimes you see ... .. 12V on pin 8 (a voltage lower than 8V is detected ... -
Issue 2 Speccy faultHi Guys, I'm really hoping someone can help me with a fault that has just developed on my issue 2 speccy. After perservering for some time with usi…
... checked (easiest to test what voltage is reaching the 4116 memory ... ).
2. If any voltage is missing, stop using it till you ... kill 4116 RAM).
Missing -5v/+12v to the 4116 ... -
Some 48k+ packages for saleSoon! Rwap is sending over a few membranes for 48k+ machines, so far, got two fully functional (and looking good!), soon as the membranes are in the…
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I carried out the voltage checks as per the service ... found that the -5V was missing so, not knowing if the ... to try and find the missing -5 volts but there is ... -
Microdrive using simple coilWhile listening to my iPod using cassette car adapter I came to idea - why not doing the same for the microdrive? Anyone ever tried that? Do you thin…
... electronics so I might be missing some important points - sorry if ... there's still place for voltage regulation (resistors?) and coils. But ... -
Second Hand SpectrumHi just joined the Forum. I have picked up a Spectrum at a s/h shop and would like some advice please. I have had two ZX81's packed away for severa…
... retro/spectrum/SRAM_replacement/"]here[/URL]), voltage conversion circuitry removed & ... connector also has unregulated DC voltage, and a +/- 12V AC ... generated by the voltage conversion circuitry. So some peripherals ... issues if that's missing. -
Second Hand SpectrumHi just joined the Forum. I have picked up a Spectrum at a s/h shop and would like some advice please. I have had two ZX81's packed away for severa…
... due to some ZX81's missing the so-called 'back porch ... 's fail to detect correct voltage levels for what's black ... -
Three faulty machines - help!I have three Spectrums and all of them have suddenly collapsed and I can?t figure out what?s wrong. New here.... I own three Speccies but all of a …
... chips are very sensitive to missing voltages. When -5 and/or ... +12 is missing (or way outside nominal) the ... is a transistor in the voltage conversion circuitry (TR4, sometimes ... issue boards used, and supply voltage readings on each? Also interesting ... -
Three faulty machines - help!I have three Spectrums and all of them have suddenly collapsed and I can?t figure out what?s wrong. New here.... I own three Speccies but all of a …
... chips are very sensitive to missing voltages. When -5 and/or ... +12 is missing (or way outside nominal) the ... is a transistor in the voltage conversion circuitry (TR4, sometimes ... issue boards used, and supply voltage readings on each? Also interesting ... -
ZX Spectrum not working... issue 4S?Hi, I've bought a "new" broken ZX Spectrum +. The idea was to put an harlequin board inside, but for the moment I'm trying to put it in working order…
... ]
[*]First check how the voltage conversion circuit is currently configured ... & re-try.
[*]Sometimes voltage conversion circuitry fails due to ... weak side. And pinout is missing from ZTX650 datasheet I have ... -
Zx 48k after the ic7805 other problemHi everyone, i am Tiago from Portugal, and i am trying to repair a Zx Spectrum 48K. the machine didn't do anything, no image, no sound, nothing. The…
... are missing then there's probably a fault in the voltage converter ... from the board), repair the voltage converter circuit and re-connect ... -
Strange failure modeI just had a 48K machine "fail" in what seemed like an odd way. Problem: Random keypresses (not from any particular part of the key matrix) appearin…
... design fault put a significant voltage on the case. Enough to ... all the mains filtering components missing :o. There were places on ... them, but they were all missing. Presumably they were only there ... -
The Disciple clone... doable?Hi. As a spectrum user in the 80's this was the dream interface all-in-one for me. I have a 48k+ and planning on get a 128K toast-rack later. Anyway…
... the schematics I've found missing pins and mislabeled ones on ... puts it through a 7805 voltage regulator. This is (or at ... -
The Disciple clone... doable?Hi. As a spectrum user in the 80's this was the dream interface all-in-one for me. I have a 48k+ and planning on get a 128K toast-rack later. Anyway…
... the schematics I've found missing pins and mislabeled ones on ... puts it through a 7805 voltage regulator. This is (or at ... -
Rocky Gush Floppy Drive InterfaceI have a Rocky Gush Floppy Drive Interface which I would like to post the details under the Hardware section of the website. What is correct procedur…
... data corruption. When the supply voltage is dropped with the LED ... all? I've noticed a missing word or two in the ... -
48k + Spectrum Issue 4S Display IssueHi all! Brand new user here. Growing up I had a zx spectrum for a little bit, and recently I have bought a working 48k + Spectrum (Issue 4). I was…
... the 7805 voltage regulator. If it's low or missing that'd ... it to have a negative voltage is very unusual. -
48k + Spectrum Issue 4S Display IssueHi all! Brand new user here. Growing up I had a zx spectrum for a little bit, and recently I have bought a working 48k + Spectrum (Issue 4). I was…
... the 7805 voltage regulator. If it's low or missing that'd ... it to have a negative voltage is very unusual.[/QUOTE]
Issue 3 board... How to resurrect?Dear Everyone, Now I have a working 48k Issue 3, a sort of working Speccy+ (still having problems with the keyboard, more of that in another post) a…
... sure about the voltage readings? With 5V missing, I wouldn't ... of your meter to the voltage regulator heatsink (as I ... power on measure the voltage between that and the ... supply. If it's missing then most likely something is ... . If the 5V is missing, then I'd try ...ZX Spectrum clock signals comparedI haven't searched for this on WoS; it might have been posted before. But I think it's important info, and can't do any harm to repeat or show from a…
... the Z80 clock, you avoid missing bits because of the ULA ... two 470 ohm resistors as voltage dividers to feed the 74LVC1G14 ...First time capacitor replacementHi, I have an Issue 2 board, that i wish to start with recapping as advised on here, as they look to be all original. (Same with V3 board, but going…
... they are missing, renew it.
The 7805 voltage regulators often ...Spectrum Missing -5vMy Spectrum is "almost" booting, just when you expect the (C) 1982 Sinclair Research to appear it just displays flashing squares on the screen :( I …
... If the -5V supply is missing, there is a problem with ... (test on the 7805 voltage regulator)? If yes, then ... good +12V, check the voltage across (between the left ... If you have a good voltage here, either the zener ... or if you get no voltage, as [URL="http://www. ...The Spectrum Resuscitation ThreadKicking off this thread as a place where people who are fixing/restoring Spectrums (or indeed any other piece of related hardware) can show off their…
... as there was a piece missing from it as you can ... checked that I was getting voltage to all three rails. The ... around and also fixed the missing CPU rail with a piece ... ordered and it's also missing a few case screws and ...ZX Spectrum clock signals comparedI haven't searched for this on WoS; it might have been posted before. But I think it's important info, and can't do any harm to repeat or show from a…
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Then I tried a voltage follower, connecting the output to ... ]
What am I missing here?Spectrum Plus display issueHi, does anyone know if this is fixable at all by someone with no experience? From looking on a similar post on World of Spectrum forum they mention…
... would wager that both the voltage conversion circuitry and at least ... check will no doubt find missing -5v and +12v at pin ...ZX Spectrum 48K AV IssueOK so I dugout my old 48K Speccy today and decided to AV mod it. I did the mod (pretty easy) but the picture I am getting is this. [url=http://posti…
Ok, so the voltage conversion circuitry isn't working. < ... screen display is indicative of missing or non-functional lower RAM ...'Interesting' Issue 2 modSo I've been lurking on this forum for a while and I've got to the point where I want to see if I can repair a speccy.. so I bought me a 'broken' one…
... signal generated by the now missing on board switch mode power ... buy a 7905 or 79L05 voltage regulator. This will convert the ... the middle hole for the voltage regulator chip, or the mounting ... the board for where the voltage regulator and heatsink attached are ...Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
... coil (sick Spectrums with bad voltage are often silent as they ... bad (unlikely as it's missing -5V and +12V) you need ...Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
... coil (sick Spectrums with bad voltage are often silent as they ... bad (unlikely as it's missing -5V and +12V) you need ... ?
Would you change the voltage regulator also?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_…
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I swapped out the voltage reg for a new one ... ]
Then replaced the missing D13 diode...
[IMG ...
