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eBay 128K Spectrum RGB cables overheat the Spectrum!?Hi everybody, For a long time I've wondered why Spectrum 128K Toastracks were overheating when using my Retro Computer Shack RGB SCART cable. Today …
... place a 2.7V zener diode or a green LED from ... -
Dot crawl?Hi, As I'm rather new to the hardware of the spectrum, just to confirm: is this video showing "Dot crawl" ? [url]https://www.youtube.com/watch?v=_U…
... you just put a 1N4148 diode into the circuit (in series ... of a volt through the diode, but 4.3V should be ... -
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 …
... you have tested between the diode cathode ("k") and the contact ... ) resistance range? And between the diode anode and the address pin ... are okay, try renewing the diode (use a 1N4148 or equivalent ... -
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 …
OK all those tests are fine and the diode tested fine but just in case I replaced it anyway.
I have the same problem however. -
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 …
... :(:confused::x
Which diode is it? Having had a ... 1 to 5 connected to diode D1 which connects to address ... -
Spectrum 128 malfunctioning with DIVMMCI recently got myself a spectrum 128 (toastrack) and a DIVMMC card so I could load games from it. It all works fine until it has warmed up and then t…
... . The voltage drop across a diode reduces slightly when it gets ... -
VERY loud beeper!!I recently replaced a dead beeper with another from an old set of headphones, only this is MUCH louder! Is there a way of bringing the volume down a …
... the ULA via a 1N4148 diode, but the collector is supplied ... -
ZX Spectrum Clock Signal Restorer Circuit[SIZE=5][U][B]ZX Spectrum Clock Signal Restorer Circuit[/B][/U][/SIZE] The circuit below is an experimental circuit. It has only been "tested" using…
... . If you put a double diode like BAV99 in the 5V ... -
ZX Spectrum Clock Signal Restorer Circuit[SIZE=5][U][B]ZX Spectrum Clock Signal Restorer Circuit[/B][/U][/SIZE] The circuit below is an experimental circuit. It has only been "tested" using…
... .3V voltage regulators, a double diode of BAV99 would do the ... -
Points on +2 Cassette to add Mono plugHi All, I am looking for the points on the ZX +2 cassette board where I can add the wires to a mono jack to load from WAV Anyone help?
... is no series capacitor and diode to raise the signal above ... -
Issue 3B no soundI just noticed that there's no sound in the Issue 3B Speccy that I've been fixing. Is it more likely that the speaker is bust or is it TR7 and D9? …
... TR7 and test with the diode test function of your multimeter ... -
Issue 3B no soundI just noticed that there's no sound in the Issue 3B Speccy that I've been fixing. Is it more likely that the speaker is bust or is it TR7 and D9? …
Issue 3B no soundI just noticed that there's no sound in the Issue 3B Speccy that I've been fixing. Is it more likely that the speaker is bust or is it TR7 and D9? …
[QUOTE=1024MAK;779815]
So, as I was saying, it's always due to a faulty 1N4148 diode, every time :[/QUOTE]
:lol:
BZX 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…
... /> If your meter has a diode test function, you can do ...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 …
Agreed, change all the electrolytic capacitors first.
Also, check the 5v Zener diode (D16).
I fixed an issue 2 earlier this year where failure of that diode took out the -5v rail.
BZX 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 …
... electrolytic capacitor, a faulty Zener diode (short circuit) or one or ...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 …
... believe the Zener diode is fine as the diode test function on ...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 …
The zener diode is D16, not D12. I am not sure whether your Fluke can check zener diodes, the usual diode check goes wrong.
What about the -12V?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 …
... />
D16 is a "zener diode", right? But how can I ... the above (TR4, TR5, coil, diode) is in good working order?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 …
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 …
... .1V 400mW or 500mW Zener diode is what you would need ...Burned finger temp on rubber 48k heatsink normal?Ok so i opened it up because a few keys started to act up and i noticed that after burning my hand the heatsink was that hot i could actually smell t…
... the part you insert a diode I didn't understand what ... type of diode you used.:-?
Could you ... an example of a suitable diode?Burned finger temp on rubber 48k heatsink normal?Ok so i opened it up because a few keys started to act up and i noticed that after burning my hand the heatsink was that hot i could actually smell t…
... 't understand what type of diode you used.:-?
Could you ... an example of a suitable diode?[/QUOTE]
Almost any ... ordinary silicon diode that can handle the current ... . Don't use a Schottky diode or any other special purpose ...Powering a Spectrum with 5v?I live in the States, but I'm originally from England. My original Spectrum is still at my mum's house in the UK, and I was thinking of asking her t…
... and used a old conventional diode bridge and cap supply. I ...Burned finger temp on rubber 48k heatsink normal?Ok so i opened it up because a few keys started to act up and i noticed that after burning my hand the heatsink was that hot i could actually smell t…
... ;783085]Almost any ordinary silicon diode that can handle the current ... 't anything special about this diode, it's just what I ... . Don't use a Schottky diode or any other special purpose ...Burned finger temp on rubber 48k heatsink normal?Ok so i opened it up because a few keys started to act up and i noticed that after burning my hand the heatsink was that hot i could actually smell t…
... /> I decided to put the diode in according to Zorn's ... a small section of the diode leg un-insulated I am ... )
Could a second diode in series be of additional ...Burned finger temp on rubber 48k heatsink normal?Ok so i opened it up because a few keys started to act up and i noticed that after burning my hand the heatsink was that hot i could actually smell t…