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1st interface in 30 yearsHi all, The last time I built a ZX Spectrum interface was 30 years ago, so today I gave it a whirl with an external rom. Switchable in/out of course…
... connect a 8.2V zener diode and a 180 ohm resistor ... -
Next step for fixing my speccy?Hi guys, I've picked up my faulty Spectrum aiming to fix it. So I followed the excellent JouledperCoulomb videos on Youtube for the basics and I am …
... TR4/5 as the Zener diode may be acting up or ... -
Next step for fixing my speccy?Hi guys, I've picked up my faulty Spectrum aiming to fix it. So I followed the excellent JouledperCoulomb videos on Youtube for the basics and I am …
... TR4/5 as the Zener diode may be acting up or ... -
Next step for fixing my speccy?Hi guys, I've picked up my faulty Spectrum aiming to fix it. So I followed the excellent JouledperCoulomb videos on Youtube for the basics and I am …
... there is a series diode after the Zener diode. This will reduce ... the voltage across the Zener diode first. Sorry, I'm on ... schematics to give you the diode reference number is not very ... -
Next step for fixing my speccy?Hi guys, I've picked up my faulty Spectrum aiming to fix it. So I followed the excellent JouledperCoulomb videos on Youtube for the basics and I am …
... the -5V at the Zener Diode as Mark suggested. I have ... -Schematics.gif"]here[/URL] the diode should be D19 (which I ... -
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_…
After testing TR4 in diode mode I got 6.9V/ ... -
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_…
Issue two - no ZTX 450 in the output audio - so, test:
D9, 10 and 13 as well as the caps and resistors mentioned earlier (R36, R37, C32 and C35) -
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_…
... audio - so, test:
D9, 10 and 13 as well ... -
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_…
... (NOT continuity) across the diode. If you get a ... not the other, the diode is probably okay - if ... a reading both ways, the diode has gone "closed".
... br /> If you have a diode test function on your meter ... />
Remember, a diode will pass current in one ... -
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_…
... me and my meter has diode test mode so I've ... -
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_…
The diode (one of them) is that glass component with the yellow bands
Hold on, am looking out an issue two board -
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_…
D9 and 10 are the lower of the two diodes - left of the speaker
Therefore I assume D13 is the one behind the mic socket (IT IS)! -
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_…
... of a mess of that diode now the leg snapped and ... -
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_…
... I will order a new diode and fit it and then ... -
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_…
... loading signal is too low, diode(s) damaged, a buggered speaker ... -
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_…
Don't bother ordering a 1p diode ffs, just PM me yer addy, I'll send ya some -
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_…
Right, then I suspect too low a volume, and a buggered speaker. Switch your meter to the diode test range or a resistance range, and test the speaker - you should get around 30 ohms as a reading, but more important, hear a crackle out of it.... -
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…
... are my results of the diode tests on tr4 and tr5 ... -
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_…
... /> Then replaced the missing D13 diode...
[IMG]http://s26 ... -
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_…
No, I'm not kidding lololol
In that pic you've posted, the black band of the diode is facing down - it should face the socket :)
Trust me, I'm a minor diety xD -
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_…
... I've just swapped that diode out and a new one ... -
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_…
... I've just swapped that diode out and a new one ... -
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_…
... know you were missing a diode on the EAR socket. :) It ... -
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_…
... out it was D9 after all)
[*]D9 to actually fix the ... -
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_…
... know you were missing a diode on the EAR socket. It ... this before i removed the diode too.
[QUOTE]Of ... -
'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…
TR4 has likely been destroyed - remove it, but don't fit a replacement yet!
Does your meter have a diode test?
[I][B]Mark[/B][/I] -
'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…
'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…
... . Change C46, then the Zener diode at D16 (5v1 Zener) if ...