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Hot plugable edge connector?Could the spectrum's edge connector have been made hot plugable without adding much to the manifacturing costs? I was thinking along the lines of a…
... discovered the edge-connector was missing the locating pin), when I ... wrong polarity or excessive over voltage. Watching a chip blow it ... .
Maybe a power supply voltage gets onto a line, but ... -
'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…
... longer the chance of a missing -5V supply causing further ... take your time doing the voltage readings.
The ... is produced by the 7805 voltage regulator, which should work ... will be missing (around 0V) or well outside the required voltage range ... -
Smokin... more 48k woesHi, it looks like I've converted another Spectrum 48K+ into a smoke machine. I'd been rebuilding an Opus Discovery unit and everything looked good. …
... think that the +12V are missing. You should measure at the ... C45. )If there is that voltage, TR4/Tr5 are o.k ... -
Smokin... more 48k woesHi, it looks like I've converted another Spectrum 48K+ into a smoke machine. I'd been rebuilding an Opus Discovery unit and everything looked good. …
... think that the +12V are missing. You should measure at the ... C45. )If there is that voltage, TR4/Tr5 are o.k ... -
Just Speccy 128Wow, got home and found that I have received a parcel from Zaxon containing a Just Speccy 128 PCB :-) B-)<br>Now all I need is a parts list, th…
... keen in having the rated voltage of a 'lytic too far ... on this board. Getting low voltage, low capacitance electro's is ... stock 1uF electro's with voltage ratings below 50V or 63V ... on the board, U15 is missing from the parts list, but ... -
not working issue 3Hi all, I received this mobo from ebay, after start i have this on screen [img]http://forest.no-ip.org/wos/issue3_01/20150728_135908.jpg[/img] …
... with completely failed or missing lower RAM and that' ... possible other components in the voltage converter circuit have failed, ... checking the diodes in the voltage converter circuit too.
... and the diodes in the voltage converter circuit.
- ... -
Sudden death of ZX Spectrum 48KHello A friend gave me a 48K rubber keyed Spectrum. I brought it home, hooked it up to my little TV and powered it up. I was very happy to see t…
... is bent to fit the missing one's hole on the ... you guys before proceeding with voltage checks.
Here's ... -
Dead issue 3b with black and white barsHi all, I've been donated an issue 3b which has some nice black and white bars with a few flashing blocks. I've done a few RAM tests and could spo…
... loss of the -5V bias voltage. This type of DRAM chip ... -5V is shorted out, or missing, or worse, if the -5V ... supply is missing and internal electrical leakage currents ... supply to develop a positive voltage, parts of the silicon act ... -
Opus Discovery "the big switch on" (after 20 years)I have a few of these Opus Discovery's with different Eproms in that have not been swiched for 15-20 years or so . I am in no rush to switch any on …
... on this one is not missing/blank as first thought but ... with a Multi-meter showed voltage readings of 11.90 volts ... -
No video from my Spectrum +3 hot chips!I still can't get to the bottom of my +3 giving no video. It powers up and both the power and disk drive lights are on solid. The disk drive won't ma…
Could a voltage rail be missing from the PSU? I'd be opening that up first to check the fuses inside haven't blown. -
So for my first trick...I'm sure people have already used the AD724 or AD725 on other 8 bit machines, and i know the Harlequin uses the 724, but not seen anyone trying to us…
... gray Spectrum +2 computers with missing 12V. The computer itself runs ... but the TEA2000 needs that voltage. In some cases electrolytic capacitors ... -
Black screen on 48k+Hello peeps Just bought a 48k+ was working fine then after leaving it off over night I turned back on to get a total black screen, no border etc. …
... CPU is disabled, dead or missing. Typically if the CPU is ... heatsink attached to the 7805 voltage regulator or to the case ... unregulated type. This means the voltage depends on the load current ... -
48k Speccy died, resistors getting too hot to touchHi folks, With 2 days to go till an exhibition my trusty dual-boot 48K issue 3b that I made last year has given up the ghost and I'm not sure I ha…
... and -5 and +12 were missing, but TR4 and 5 were ... coil died which took out voltage to the lower RAM which ... -
Spectrum 128k 2a or not 2b....Just picked up a +2 black case version and I'm in as little bit of a quagmire, The case is definitely black, has '+2A' stamped on the bottom, but in…
... soldered links and adding the missing resistors. I may be wrong ... the same out-of-spec voltage level issue for the blanking ... ). This will result in the voltage on the SCART blanking input ... -
Spectrum 128k 2a or not 2b....Just picked up a +2 black case version and I'm in as little bit of a quagmire, The case is definitely black, has '+2A' stamped on the bottom, but in…
... soldered links and adding the missing resistors. I may be wrong ... the same out-of-spec voltage level issue for the blanking ... grey to get the correct voltage level for blanking? Is there ... mod to get the correct voltage levels for both the blanking ... -
No video output from Spectrum +2 (light grey)Got a strange issue with my Spectrum +2 light grey edition. It was working fine then all of sudden it outputs a black screen while I was using it wit…
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If the voltage on C41 is missing or low (below 10V ... -
British Airways Systems Failure.So unless you have been living under a rock for the past 24 hours, you will have learned that British Airways (BA) have had a major IT systems failur…
... spaces for six, one was missing, two were working, the other ... difference as the 50V battery voltage had dropped to about 25 ... -
I can't get my +2B to work over RGB to SCART.Hi so I have a black +2B and no matter what I do I get a black screen using the RGB-SCART scart cable (specific for the model ) and I'm using a SCART…
... can open) and measure the voltage with the SCART connected to ... inside the converter is either missing or, judging from the fact ... -
I can't get my +2B to work over RGB to SCART.Hi so I have a black +2B and no matter what I do I get a black screen using the RGB-SCART scart cable (specific for the model ) and I'm using a SCART…
... can open) and measure the voltage with the SCART connected to ... inside the converter is either missing or, judging from the fact ... -
Spectrum 128k +2 video issueHi Guys, I just got a Spectrum 128k +2 from ebay. It came with its power supply and the scart video cable. The machine is working pretty good but …
... with the SCART RGB blanking voltage pins (which I suspect it ... /> @guesser: Sorry, maybe I am missing something, but why replace R9 ... -
Troubleshooting my +2To put this in context: a while back (i.e. late last year and earlier this year) I was looking to put together a compilation of modern Spectrum games…
... load (the computer), the output voltage will be greater than the ... out there seem to be missing the power supply? It doesn ... -
The InstructionsI thought I had better put "the instructions" in miscellaneous as I had no idea where "the instructions" would send me I am , of course referring …
... I can guess Over Voltage Protection and Under Voltage Protection but I ... Protections.. Maybe a couple are missing ? -
128K +3 RepairHi guys, I need some help to diagnose a faulty 128k +3. The unit is completely unresponsive. I had tested the PSU and found odd values in it. …
... and -12V, but 5V is missing (multimeter only shows a 0 ... .
If I measure the voltage behind the power socket, I ... pins I have the wrong voltage. Also, I have continuity between ... took some measures and the voltage is consistent with the psu ... -
Another Spectrum is brought back to life.Hi Spec-chums. I have been having bit of busy afternoon with repairs today. I've brought back to life a Panasonic Super-VHS recorder, and more intere…
... inspection looking for damaged or missing parts / bad connections.
voltage range to test the various ... -
Finding a good (UK) external switch mode power supply for the basic 48k and 128k ZX SpectrumsThis idea has probably "done the rounds" by now . I think I have heard about it a bit late . This thread with look at replacing the original "heavy l…
... if I'm wrong or missing something. :-? [/quote]
The ... is separated from the low voltage secondary winding by being ... to correctly regulate the output voltage, it is possible that ... replace the 7805 three terminal voltage regulator with a modern mini ... -
Understanding tape edgesI've never done any tape reading code. But I've read about these "edges" on multiple occasions. Trouble is I don't understand what they heck they are…
... ) ... what exactly is the threshold voltage that ULA uses to extract ... 6 is 1 if the voltage on pin 28 is over ... are the same, you're missing something between them. What about ... -
Understanding tape edgesI've never done any tape reading code. But I've read about these "edges" on multiple occasions. Trouble is I don't understand what they heck they are…
... ) ... what exactly is the threshold voltage that ULA uses to extract ... ” book gives the input threshold voltage as 0.714V.
voltage at the ULA pin. However ... are the same, you're missing something between them. What about ... -
The Complete List Of The Causes Of Lower Ram Failure?Well the aim is to get a comprehensive list.I ask this because I know very little about it . I know that failure of "power supply" related capacitors…
... might be possible with residual voltage left on the circuit after ... bits to lose or having missing such as the TV , the ... the various leads . All this missing stuff ? Amazing it must be ... -
The Complete List Of The Causes Of Lower Ram Failure?Well the aim is to get a comprehensive list.I ask this because I know very little about it . I know that failure of "power supply" related capacitors…
... without any normally fitted parts missing, in general, the originally fitted ... the passive components and the voltage will be limited to within ... -
Two new spectrums arrived. One no video.Got a +2 and a Toastrack arrived today. Toastrack was actually in good condition, little wear, though a little dirty. Worked well on first power up, …
... to AMPS and checked the voltage... Not good... But. It's ... of dry joints. VHF modulator missing. But otherwise this +2 seems ...
