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Is This PSU Useable on the Speccy?I just got my Speccy and the PSU has had some 'work' done to it. Somebody has added an extra length of cable on it but rather than soldering or crim…
... the reason everyone reports different no-load voltages for their speccy PSU ... -
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…
... />
[QUOTE=CaptainHayashi;701778]No beeper or keyboard response, white ... to do is check the voltages at various key points, especially ... of call are check the voltages, replace any capacitor that looks ... -
Which ULA?Just a quick question, more of interest rather than immediate need... I am thinking ahead about the repair of an Issue 2 board, and also an Issue 6A …
... morning, but if I have no joy, I guess the ULA ... my next step.
Voltages seem to be fine to ... -
Cascading transistorsMiguel (mcleod_ideafix) alerted me on an aspect of a design I'm working on where I am cascading transistors, which may give problems. This is the par…
... is 1, so there is no voltage amplified. T2 only makes ... direct coupling as such is no problem, as long as care ... the 0.6V region, lower voltages would not 'open' T1 and ... higher voltages would almost immediately force T1 ... -
+3 Membrane Scheme??I've been looking and only find the scheme Sinclair models, and would need to find the +3 keyboard scheme. Does anyone have it? Thanks
... no idea what could be causing this. I suspect the voltages used ... -
What models are repairable these days?I've followed a few threads which are trying to repair the mainboard components of the older 48K models, but it got me wondering - is it possible to …
... don't like you sticking voltages on input lines, but that ... flaw! :-o[/QUOTE]
No, directly into the tape I ... -
Issue 2 crashes after about 30 minsHi Guys, I have an Issue 2 zx spectrum that seems to get graphic corruption after about half hour of playing, then finally falls over and crashes. …
... in voltage between load and no load is due to the ... suggested to start measuring the voltages and current drawn by the ... -
The "best" Z80?What's the best Z80 for Spectrums? I know there are differences between brands (Nec, Zilog, Thomson) and technologies (CMOS, NMOS), so what Z80 woul…
... to speak them out, no, you also resist to ... />
There is no English equivalent of "milliard" so ... that time there were no such heavy appliances. So ... the delivery of high voltages to the curbside wasn ... it down to household voltages. This means the wire ... -
Transistors 101Hi, Im a complete novice when it comes to electronics and would appreciate any help that can be given. Im replacing the transistor that sits on to…
No +12V (or a very low ... resulting in no picture.
Check all supply voltages, +9V input ... -
ZX spectrum 128K + 2 (Grey one :)Hi all, I'm trying to revive a dead ZX 128K +2 (the grey one). The regulator was damaged and seemed to be feeding 7.8Volts onto the pcb. Yikes ! I…
... m afraid I can report no progress, except that the ... on screen.
Still no 12Volts.
TEA2000 pin ... supply)
I checked voltages across:
R55 (1K8 ... ?
I figure that no oscillation is happening...
Anyone using an RGB SCART cable with a +2A/+3 and LCD TV?In [URL="http://www.worldofspectrum.org/forums/showthread.php?t=44697"]a recent thread[/URL], I mused: [quote]Can +2As be composite modded? If so, I…
... This is because SCART requires voltages within certain ranges present on ... This is why there is no vertical and horizontal sync inputs ... you can't derive these voltages from the +3 RGB socket ... you must obtain the switching voltages from elsewhere.
...Anyone using an RGB SCART cable with a +2A/+3 and LCD TV?In [URL="http://www.worldofspectrum.org/forums/showthread.php?t=44697"]a recent thread[/URL], I mused: [quote]Can +2As be composite modded? If so, I…
... years ago, yes, but now, no. [URL="http://en.wikipedia.org ... ]This is why there is no vertical and horizontal sync inputs ... VDU's / monitors that had no separate sync input at all ... need to supply the correct voltages to SCART pin 8 and ...Anyone using an RGB SCART cable with a +2A/+3 and LCD TV?In [URL="http://www.worldofspectrum.org/forums/showthread.php?t=44697"]a recent thread[/URL], I mused: [quote]Can +2As be composite modded? If so, I…
... ago, yes, but now, no. [URL="http://en.wikipedia.org ... s / monitors that had no separate sync input at all ... the reason SCART has no sync input for component ... to supply the correct voltages to SCART pin 8 ... words, feed it the voltages the spec demands and you ...IF2 troubleMy IF2 has been happily working forever until today, no matter what Spectrum I plug it into I get coloured blocks all over the screen, did the obviou…
... mainly use that to test voltages although it can do resistance ... confirm that the tracks have no breaks. Put one meter probe ... could substitute?[/QUOTE]There is no known drop in replacement. And ...Toastrack trouble[IMG]http://i44.tinypic.com/11lq7id.jpg[/IMG] Sorry about the picture size, cant figure out how to make it smaller! Anyway, the pic says it all, th…
... have a look at those voltages and report back, oh yes ... soldered/connected and there is no damage to the 0V/ground ...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…
... the open circuit / no load voltages, or the voltages with the Spectrum connected ... 4.92.[/QUOTE]
These voltages are all okay :-)
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…
[QUOTE=1024MAK;731669]Are these the open circuit / no load voltages
[I][B]Mark[/B][/I][/QUOTE]
Yes with ground probe in centre and red on outside cover, unplugged.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 …
... being sold and so have no knowledge on how they are ... for creating the necessary control voltages for the SCART socket. The ... which of course is a no-no.[/QUOTE]
As has ... from the monitor socket, although no where as severely as using ...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…
... , and make your own go/no go set of tables from ...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…
... on screen, fast check of voltages get me +3.5v on ... , but now I get right voltages 4.95,-5,12, still ... surprise all keys working fine, no need of keyboard membrane :) I ...Some problems with 2 ZX Specturm board'sHi, last week i got some ZX Spectrum stuff. Also 2 ZX Spectrum 48K's, one in the orginal case the anoter one in a DK'tronixs case. Both have problem'…
... =balford;733973]Ok, well the voltages point to a failure of ... blow again.[/QUOTE]
No, this time there seems to ... power supply that brings all voltages down. This is because:
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 …
... is okay?
What actual voltages did you get?
EDIT: or if you get no voltage, as [URL="http://www ...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 …
... .
It seems that voltages over about 14.2v cause ... is putting out 14.8 no load and 11.6 when ...Toasted +3Oops.. I shorted one of my +3 (being clumsy with multimeter, doh) when measuring PSU connector pins :D Any immediate guesses what exactly died on thi…
... ]Where were you measuring the voltages, on the edge connector?
[/QUOTE]
No.. on the top side of ...Toasted +3Oops.. I shorted one of my +3 (being clumsy with multimeter, doh) when measuring PSU connector pins :D Any immediate guesses what exactly died on thi…
... at the schematics though, so no idea how isolated the 12V ... /> Not sure what the breakdown voltages are of things in the ...Toasted +3Oops.. I shorted one of my +3 (being clumsy with multimeter, doh) when measuring PSU connector pins :D Any immediate guesses what exactly died on thi…
... need to be said and no one disagrees that you should ... chips that work off multiple voltages (which can be damaged by ... absence of one of these voltages) so the general advice of ... short circuit anything" is good. No one is disagreeing that you ...128K RGB Display problem.I have just got my hand on a toast rack, but when powered and connected to the telly the picture jumps horizontally at random intervals. Could it be…
... is to do with the voltages required on pin 8 and ... 4:3 aspect ratio signal. Voltages less than 4.5V may ... pin 16. If there is no wire, connect a red wire ...128K RGB Display problem.I have just got my hand on a toast rack, but when powered and connected to the telly the picture jumps horizontally at random intervals. Could it be…
... is to do with the voltages required on pin 8 and ... 4:3 aspect ratio signal. Voltages less than 4.5V may ... pin 16. If there is no wire, connect a red wire ...Born again Speccy user with problemsHello all, Firstly I'd like to say a big hello - this is my first post! When I was 8 or 9 or so my dad bought a ZX Spectrum 48K and a whole bunch o…
... circuit diagrams I can see no reason why my dictaphone should ... speaker output during saving - the voltages are too low to bring ...PSU Overvoltage?Going through a pile of 48k PSU's today, rewiring and fitting new plugs, testing each one as I go I came across one that outputs 14.85v, usually im g…
... can have slightly different output voltages with the same test load ... voltage measured by a meter (no matter what type) will fall ...
