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Spectrum dead: 8 vertical bars in alternating colorsI have been soldering on this basterd for a long time now. All IC's now have sockets (except the LM1889). I swapped all 4116's by types that are 100%…
... ULA is supposed to carry +12V. +12V is perfectly available, as I ... . Hopefully that helps, but the +12V on the ULA is definitely ... -
Spectrum dead: 8 vertical bars in alternating colorsI have been soldering on this basterd for a long time now. All IC's now have sockets (except the LM1889). I swapped all 4116's by types that are 100%…
... is was supposed to be 12V. I also solved anoth mystery ... -
dead issue 6a boardI've just been back to the uk and found my old 48K + there - and bought it back with me to singapore - it's giving white border and red bars. From wh…
No, I mean the supply circuit inside the Spectrum, a DC-DC transformer that generates 12V and -5V off from the 9V main supply. -
RBG monitor for Spectrum?I'm using a very old TTL RGB monitor with my Spectrum, with a RGB adapter that I made many years for my Sinclair QL. It works perfectly with my QL, b…
... a hex inverter with a decoupling capacitor on the power for ... -
RBG monitor for Spectrum?I'm using a very old TTL RGB monitor with my Spectrum, with a RGB adapter that I made many years for my Sinclair QL. It works perfectly with my QL, b…
... , but you will loose the 12V signal, needed for some TV ... -
RBG monitor for Spectrum?I'm using a very old TTL RGB monitor with my Spectrum, with a RGB adapter that I made many years for my Sinclair QL. It works perfectly with my QL, b…
... and LK7 is absent)
+12V..........n/c..........5 (if LK3 ... -
Trouble with Spectrum 48kI think it is a Rev 3 (Issue 3 on the motherboard). The screen has weird characters, instead of text, and the keyboard is not responding (although it…
... ZTX651, restoring the -5v line. 12v line now has a value ... closer to 12v.
But I still ... -
Dead 48K Speccy.Blow this up as a child... thought I'd get it down from the loft and see if I can repair it. Upon power up, it displays this: [IMG]http://i266.photo…
... voltages at low memory (5V, 12V, -5V) and see if there ... -
Dead 48K Speccy.Blow this up as a child... thought I'd get it down from the loft and see if I can repair it. Upon power up, it displays this: [IMG]http://i266.photo…
... voltages at low memory (5V, 12V, -5V) and see if there ... -
Any help appreciatedHello, I notice that people have posted their PC related hardware and software woes on this forum before and the more technically minded among you h…
... voltage. red=5v and yellow=12v. this isn't conclusive and ... -
I bought my first ZX Spectrum 48k, now what ?Hi guys ! I recently go to Brussel in Belgium and found a ZX Spectrum at a "flea market" (sorry, I don't the correct word for that, let's call it a …
... ZX Spectrum, but only a 12V which fit perfectly. Will it ... -
I bought my first ZX Spectrum 48k, now what ?Hi guys ! I recently go to Brussel in Belgium and found a ZX Spectrum at a "flea market" (sorry, I don't the correct word for that, let's call it a …
... ZX Spectrum, but only a 12V which fit perfectly. Will it ... -
PC Cooling recommendationsLast week I bought an uber gfx card (for me, normally I stick at least two gens back, but long story short - it was a cheaper option than what I had …
... is the amps on the 12v rails. the last PSU i ... /image_03.jpg"]72amps on the 12v rail[/URL], but for your ... -
Snow on screen of 48K Speccyok you wizards I fixed up my 4116 ram issue as Winston and McLeod advised me before by replacing with 4164's.... all I could find here in Singapore (…
... enough stable power supply of +12v, maybe because those ceramic ICs ... -
Snow on screen of 48K Speccyok you wizards I fixed up my 4116 ram issue as Winston and McLeod advised me before by replacing with 4164's.... all I could find here in Singapore (…
... to suggest the +12v line seems wrong - the 12v line in my ... -
Another set of USA newbie ZX Spectrum questions.So yeah, I'm considering getting a ZX Spectrum 48k pretty soon, but since I'm not in the country of origin, I have a few questions about it. First, …
... used by the +2A. The -12V aren't necessary unless I ... -
Diagnosing Spectrum 48k (faulty RAM chip?)I have a Spectrum 48k (I believe it may be an upgraded 16k model) that doesn't work, and never has ever since the owner gave it to me. When you turn …
I've just measured the internal voltages as per the service manual on this site, and both points that are supposed to be 12V actually measure around 10V - would this be the cause of my problem? Which component is to blame? -
Diagnosing Spectrum 48k (faulty RAM chip?)I have a Spectrum 48k (I believe it may be an upgraded 16k model) that doesn't work, and never has ever since the owner gave it to me. When you turn …
... mode supplies). You should have +12v, +5v and -5v available on ... -
Diagnosing Spectrum 48k (faulty RAM chip?)I have a Spectrum 48k (I believe it may be an upgraded 16k model) that doesn't work, and never has ever since the owner gave it to me. When you turn …
... would be missing (and the +12V a little too low)? -
Diagnosing Spectrum 48k (faulty RAM chip?)I have a Spectrum 48k (I believe it may be an upgraded 16k model) that doesn't work, and never has ever since the owner gave it to me. When you turn …
... ).
The lower-than-12v suggests that something is loading ... -
Diagnosing Spectrum 48k (faulty RAM chip?)I have a Spectrum 48k (I believe it may be an upgraded 16k model) that doesn't work, and never has ever since the owner gave it to me. When you turn …
... =Winston;398708]The lower-than-12v suggests that something is loading ... -
Alternative power supply for a +2B?Hi friends, On impulse, I recently bought a ZX Spectrum +2 (unit only, untested) on eBay, thinking that the cables (specifically the power supply) o…
... br /> The +2B needs +5V, +12V and, if memory serves me ... well, -12V. The only critical voltage here ... is +5V. +12V is used to feed the ... the RS232 line converters. -12V is used for RS232 ... power jack to take +12V also from the monitor, ... -
Alternative power supply for a +2B?Hi friends, On impulse, I recently bought a ZX Spectrum +2 (unit only, untested) on eBay, thinking that the cables (specifically the power supply) o…
the CD32's PSU is +5v/+12v/-12v definitely needs to hack the (DC) socket...
the C64's PSU is +5v/9v-AC not suitable for any speccy.
chris -
Alternative power supply for a +2B?Hi friends, On impulse, I recently bought a ZX Spectrum +2 (unit only, untested) on eBay, thinking that the cables (specifically the power supply) o…
Hmmmm, I've found I also needed the +12V to get an RGB display on my +3 - my PSU had a bad connection on the 12V line, and every time it died, so did the display (although the rest of the computer - except the floppy drive - continued to work). -
Alternative power supply for a +2B?Hi friends, On impulse, I recently bought a ZX Spectrum +2 (unit only, untested) on eBay, thinking that the cables (specifically the power supply) o…
Yes, -12v is also required to power the floppy drive. That's the reason for the -12v 700mA required in +3 power source (vs 200mA in +2A).
Why not using a "hacked" PC power source? -
Trying to repair a 128K (heatsink)I've bought another ZX Spectrum 128K (heatsink model), but unfortunately the last owner did not tell me it did not work.... Because this Speccy also…
... capacitors. And try adding a decoupling capacitor (20-100 nF) between ... -
Alternative power supply for a +2B?Hi friends, On impulse, I recently bought a ZX Spectrum +2 (unit only, untested) on eBay, thinking that the cables (specifically the power supply) o…
... found I also needed the +12V to get an RGB display ... /> I can't see why 12V is really needed to form ... picture... unless your TV needs 12V from the RGB DIN socket ...