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zx 48k ribbon cables slotOne more question regarding the zx 48k: the other 48K i have, and this one is working fine, i had to open it compare the voltages with a broken one..…
... to open it compare the voltages with a broken one.... and ... -
Faulty Grey Spectrum +2 - help neededI have a faulty spectrum +2. I tested the voltaged inside - all check fine. Well, within some limit, +5 for example is 4.83, but all other voltages a…
... 4.83, but all other voltages are present.
I ... is okay, CPU is okay, voltages are fine. What's left ... -
ZX81 back porch fix using LM1881Hello! Has anyone here did the back porch fix for ZX81 using LM1881? I did it this weekend and instead of clear black on white i got black on dark g…
... .uk/ZX80_ZX81/forums/composite-mod-voltages-t622s20.html-sid=84097263317ce0c752d9e0f76f020a15[/url ... -
Anatomy of a bad M1No, not the motorway (although at times the tarmac M1 goes about as well as this one...) But the bad M1 problem that seems to occur most with issue …
... to DC so the the voltages reached (high and low) by ... -
48K and wavy lines.It seems all Spectrum related things are breaking here at casa de Don Pedro. After the problem with my old ZX81, I went over to my issue 2 ZX Spectru…
... at hand? I checked the voltages at TR1 and TR2 and ... -
Lower Memory - Why Multiple Voltages?Having spent much of the weekend working on getting my old Spectrum working, my Dad (who is visiting) and I were chatting about the schematic. Given…
Having spent much of the weekend working on getting my old Spectrum working, my Dad (who is visiting) and I were chatting about the schematic.
Given that the upper RAM in a Spectrum is of type 3732 - which only has a supply voltage of +5V, why ... -
Help me resurrecting a 128KHello to everybody. I'm really struggling along a repair of a standard 128K a friend of mine handed me over some (ok, actually a lot of) time ago. A…
... , ROM and PAL without luck. Voltages are well within tolerances and ... -
Dedicated Spectrum Emulation Machine Based on Raspberry PiI've mentioned this in another thread, so I thought I'd give it a thread of its own. I've wanted to build a dedicated Spectrum emulator for a long t…
... sheet to isolate the dangerous voltages.
Then I shortened ... -
The great 128k ConversionWell, I am not sure if it is going to be great. Hopefully it will! This evening, I set about getting my Issue 6A Spectrum Plus working. I suspecte…
... didn't survive the funky voltages.
[IMG]http://i590 ... -
Issue 2 video problemHello all, Need some help with an issue 2 board that I 'm trying to restore. I've replaced all the electrolytic capacitors, changed the voltage regu…
... oscilloscope, but I can measure voltages and follow schematics for the ... -
Want a new old PC.Does anyone know of any good place that sell slightly older desktop PC's very cheap? The motherboard in mine is on its way out. Think there is a cr…
... down firmly, testing all the voltages from the power adapters i ... -
Thinking of modding an Atari paddle controller for games like Arkanoid...Hello, Was thinking of trying out a controller mod using an Atari 2600 paddle controller to use with games like arkanoid, Batty, etc... The paddle c…
... comparator to convert the analog voltages to digital (left and right ... -
Help reviving a 128 +2 GreyHello m8s, my turn to ask for some help with a +2 Grey. Got it for spares as I do have a working one but I could not resist to try and fix it. As us…
... 78s05 and ztx651 and ztx213, voltages seamed good, tried to power ... same. Then I start measuring voltages at the ram pins since ... -
Yet another glitchy graphics 48kHeyo, I'm new both to the forums (sorry if this is the wrong forum) and to Spectra I'm afraid, picked up a 48k from a steam fair sale thingy (not th…
... (a bit under the rated voltages but not too much), and ... -
Issue 4A issuesHi all, I've been trying to get the Issue 4A board that came DOA with the case I purchased for my Frankenspectrum to work. I've recapped and socket…
... IC6-IC13 are getting correct voltages. However I get the screen ... -
Issue 4A repair attemptI think I need some help. I have a nice Issue 4A main board here, which does not give out any video signal. I checked some voltages (the ones that se…
... video signal. I checked some voltages (the ones that seemed safe ... . Now I have the two voltages, but still no picture. I ... -
DivMMC clock bufferI have completed the first DivMMC EnJOY today: [url]http://www.worldofspectrum.org/forums/showthread.php?t=44238[/url] But there is a problem with t…
... can cope with different supply voltages.
But that circuit doesn ... -
Strange cures for a ZX Spectrum +2I have been looking for a +2 now for more than 2 years since I started collecting and restoring Spectrums again. I won a few on eBay, but was unsucce…
... keyboard did not work. The voltages tested OK. I was unsure ... -
Beta Disk MicroP 3.5 Disk Drive DIN Connectors signalsHello, I own a Beta Disk with an 3,5" Disk Drive from MP (MicroP) which has two DIN Connectors. One is a DIN Connector with 5 Pins, the other a DI…
... />
Does anyone know, which voltages I have to connect to ... -
are 4164's the same as mt4067-12just wondering if I can use as direct replacements as I have a +2a here with ic5 and ic4 overheating, also what are the correct voltages for these ic…
just wondering if I can use as direct replacements
as I have a +2a here with ic5 and ic4 overheating, also what are the correct voltages for these ic's?
thanks in advance -
I've had better nights...So I got a broken issue 2 today, case in good nick but the diags board showing multiple failures in both lower/upper RAM. Never mind, good as a spare…
... to the bin restored the voltages, however I've now got ... -
Tricky ZX RepairHello guys, This time I put my hands on a very nice Issue 3 16K, upgraded to 48K. To bertter explain "nice", it is absolutely mint, not a scratch on…
... checks showed that all the voltages were well within limits, no ... -
Interesting 48K failureI thought I'd recount a failure I've not seen mentioned before that I saw tonight while fixing a 48K issue 6 board. The background: The initial fail…
... thing I checked was the voltages and -5v was not present ... the board and tested the voltages again. Surprisingly, -5v was now ... -
Edge Connector InformationHi Everyone, Hope I'm posting in the correct forum. I've recently been playing with an Arduino and got to thinking it would be fab if I could do so…
... details of the pinouts including voltages but I cannot seem to ... -
TR4 or TR5?My issue two gives horizontal bars on bootup. Flicking reset takes it to copyright screen though. I measured voltages and got 4,9V, 11,99V and -4,3V.…
... copyright screen though. I measured voltages and got 4,9V, 11 ... -
Harlequin - usefull mods and addsHello, I start here a thread regarding mods and adds for the Harlequin. It was found: * that the Sinclair Interface 1 does not fully work at the Ha…
... cases the absence of the voltages of the transverter of the ... -
New user with a dead 48k issue 2Hello all I've found my way here from watching some excellent youtube videos by Joulesper Coulomb in an attempt to fix a issue 2 rubber key 48k I bo…
... the youtube video and the voltages at the lower memory when ... -
Spectrum+ keyboard issueHi I have a spectrum+ (issue 4s board) where the 1-5 keys do not work. I have replaced the membrane and checked for continuity. I have also tested …
... . I have also tested the voltages compared to the other keys ... -
ZX Spectrum 48K Issue 3, loss of -5V rail.Hi all, I've googled this problem and poured over the electrical diagrams for the circuitry concerning the power supplies and I believe I know what …
... of the board.
All voltages are present and correct except ... -
Modern day replacement powersupply for ZX 128kHi All Anyone got any links to a modern day replacement powersupply for ZX 128k. I don't mind lobbing off the end and installing my own barrel, just…
Hi All
Anyone got any links to a modern day replacement powersupply for ZX 128k. I don't mind lobbing off the end and installing my own barrel, just all the voltages to be correct.
Thanks as always
B
