-
Trying to repair a Speccy 48k - No PulsingI've had this machine for ages. I'd I've been putting off fixing it for some time now. So a couple of days ago I pulled it apart and started prob…
So the complete fix was
- Replace TR4 & TR5
- Replace ULA
- Replace Z80
- Replace 5 of the 8 RAM in the lower bank
Phil -
48k Issue 6a Very sick indeed.Hi Guys. I have a 48k Issue 6a board that shows a white screen with grey border. The white screen has three black squares spaced equally on the le…
... not work correctly with the Tr4/Tr5 circuit.
Several transistors died ... -
48k packed up after cap changeHi all, I'm relatively new to the Sinclair world, my 8-bit repairs in past was lurking in the dark sides of Acorn, Amstrad and Commodore! I've got…
Broken Issue 2 - likely culpritsI've just got hold of an issue 2 spectrum with an interesting layout (heatsink is vertical and goes down to the speaker, some variable resistors and …
... be the inductor, could be TR4/TR5, could be a capacitor. Check ...help with issue 3 48k speccy after recap and new tr4 and tr5I have a 48K speccy that was not working. After recapping and replacing TR4 and TR5 it came back to life However after a short while running weird …
... to losing their voltages, when TR4/TR5 failed. Upper/lower ram IC ... , otherwise they aren't happy. TR4/TR5 are part of the power ...help with issue 3 48k speccy after recap and new tr4 and tr5I have a 48K speccy that was not working. After recapping and replacing TR4 and TR5 it came back to life However after a short while running weird …
... to losing their voltages, when TR4/TR5 failed. Upper/lower ram IC ... , otherwise they aren't happy. TR4/TR5 are part of the power ...12V missing on an issue 3I’ve been working on an issue 3 Spectrum +. It shows thin distorted vertical stripes on bootup. +5 and -5V are all right but the 12V line measures ro…
... is in spec, then TR4 & TR5 are very unlikely to be ...48k Spec with composite video mod, screen adjustment possible?I've had a 48k Speccy with a composite video mod for a few years now, and although it works perfectly otherwise, the screen isn't centered correctly …
... is the issue of the TR4/TR5 being fitted wrong on some ...TR4 or TR5?My issue two gives horizontal bars on bootup. Flicking reset takes it to copyright screen though. I measured voltages and got 4,9V, 11,99V and -4,3V.…
Tr5 tr4I need to replace tr4 and tr5... What arr the fine replacement equivalent? I see the sinclair logo copyright but is distorted and in two line... Ca…
I need to replace tr4 and tr5... What arr the fine replacement equivalent?
I see the sinclair logo copyright but is distorted and in two line... Can everyone help me? Is a zx spectrum+ iussue 4b
Thakshelp with issue 3 48k speccy after recap and new tr4 and tr5I have a 48K speccy that was not working. After recapping and replacing TR4 and TR5 it came back to life However after a short while running weird …
... /> After recapping and replacing TR4 and TR5 it came back to life ...BeginnerIm having a go at fixing a spectrum which has been in the loft for 20 years and would like some advice please.... I have downloaded the 'spectrum se…
... , then it is not likely TR4 nor TR5 are faulty.
converter circuit (I'd just replace ... .
Sometimes the inductor coil develops a fault, but that ...what components normally get taken out if you plug+unplug a joystick interface in with the power onwhat components normally get taken out if you plug+unplug a joystick interface in with the power on? i remember doing this a few times when i had …
... TR4 and TR5, and maybe the coil (all part of the DC/DC converter ...Issue 3B problemHi! I have an issue 3B board that is having a strange problem: when I got it it didn't had the -5V and +12v, as usual. After replacing TR4 and TR5 t…
... , as usual. After replacing TR4 and TR5 the -5V came back, but ... machine seems to work, the coil buzzes but I have no ...ZX Spectrum + Revision b Power IssueHi all, I'm trying to repair a ZXSpectrum + revision 3b and at the moment the -5v is missing from the board. I've replaced the TR4 and will be soon…
... the TR4 and will be soon replacing the TR5 and maybe the coil ... the -5v, I suspect the TR5?
2] Also, does ...The rescue of a coil.The problem at hand was a known defect transformer from the switching convertor inside a Spectrum. Both windings are not interrupted and not intercon…
... How to identify a defect coil, as nothing special is ... self inductance, a good coil showed some 50 uH ... by a blown transistor Tr4. This means that too ... current has gone through Tr4, and therefore also must ... real test. Removing the coil from a working Spectrum ...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 …
... .18V. I've changed TR4 and TR5 and these are now known ... attention is drawn to the coil. Continuity-wise - it checks out ...Joytsick Interface damaged SpectrumHello All, Sob.. I am a plonker, I did the cardinal sin, I was testing a bunch of joystick interfaces that I got off ebay and one didn't have the ke…
... ?
My coil has some modification (done prior ... outer pins of the coil. A second modification goes ... inner pin of the coil. Does anyone know what ... middle).
For TR5 I'm getting 778 and ... /> So I assume TR4 is toast but TR5 is okay?
...ZX Spectrum issue 6a - yellow border problem<p>Hello!</p><p>I have problem with my Sinclair ZX Spectrum issue 6A, 48K. </p><p>I have changed low memory (all 4116 IC's) and coil, all electrolyti…
... IC's) and coil, all electrolytics capacitors, TR4 and TR5, ULA - checked, Z80 ...Faulty Issue 1Hi all, thought I'd document my efforts in getting another speccy working. I've never done this before so please bear with me... I recently took a p…
... not heard the typical coil buzz at any time ... is missing. I replace TR4 and TR5 with their modern equivalents ... and I get a noisy coil buzz which changes pitch ... 5V with a slightly quieter coil. Plug the TV in ... I can hear the coil buzz change pitch slightly ...Power issues on a 6A 48 K SpectrumHello all! I decided to take another look at my 6A Spectrum that I broke via a bad joystick adapter, I’ve removed the bottom 16K ram and replaced…
... bottom 16K ram and replaced TR4 and TR5 to no avail. From ...
[b]DC Winding Coil tests:[/b]
If I ... wrong too.
[b]TR4 Test:[/b]
This seems ... , 979 (0)
[b]TR5 test[/b]
This looks ...Spectrum issue 4SI have an almost completely depopulated issue 4s board. Wondering what to do, repairs or spares? I hooked it up and the voltages are off, 5v is fi…
... />
TR4 and TR5 are fine and so is the coil, any suggestions?Issue with TV signal + Inductor Coil (16K Issue 2 Speccy)Hello guys, I just got a 16K Issue 2 Speccy from eBay. It was sold as not working so I knew there would be some work needed before it's working ag…
... off and found out that TR4 was not working. Today I ... not find anything obviously wrong. TR4 and composite mod were the ... to be with the inductor coil which gives me +9V on ...48k Issue 6a Very sick indeed.Hi Guys. I have a 48k Issue 6a board that shows a white screen with grey border. The white screen has three black squares spaced equally on the le…
... right there? Also, the coil has also been replaced ... Both the LM1889N and coil I will remove and ... hear any whine from the coil.
My ... regulator, capacitors, and TR4 and TR5 are ok, whats the ... the previous LM1889N and coil jobs and report back ...zx spectrum 48k low -5volt raili have just received a 48k issue 3. initial tests show that all voltages are there but the -5V rail is only showing -4V. it does boot but i have tur…
... caps .TR4 and TR5 seem ok .. i dont suspect the coil as the ...Best replacement for ZTX650?What is the best replacement transistor for the obsolete ZTX650? I've read that TIP31 will do the trick. Is there a decent equivalent from the BC or …
... the ZTX650 mentioned is the TR4.
In addition to ... short circuit)
The COIL between TR5 and TR5 (does it look / smell ... voltages are present before the TR4 blows. Check one at a ...Best replacement for ZTX650?What is the best replacement transistor for the obsolete ZTX650? I've read that TIP31 will do the trick. Is there a decent equivalent from the BC or …
... remove D15 to see if TR4 blows again. This will ... an open R59 will make TR5 open wide and send ... of the coil, and eventually into the base of TR4, which ... will open TR4 too much, and ... .
BTW: Is TR5 getting hot as well ?
sinclair zx spectrum issue 6a (again) - how to repairHi All, Is there someone who may explain what these jumpers can be used for. [url]http://forest.no-ip.org/repair/jumpers.gif[/url] <- this is from …
... tr4 but no luck.
Symptoms: No buzz from coil ... br />
Replaced tr4 but the new one started ... Replaced tr5 with an BC557 and another new tr4 (ztx653) ... on. Still no buzz from coil.
Could ... it be a shorted coil? how to test?
...Issue 3B problemHi! I have an issue 3B board that is having a strange problem: when I got it it didn't had the -5V and +12v, as usual. After replacing TR4 and TR5 t…
... ;344572]
After replacing TR4 and TR5 the -5V came back, but ... machine seems to work, the coil buzzes but I have no ...Broken ZX Spectrum? :(Hi! I bought a 2nd hand ZX Spectrum half a year ago. It worked perfectly fine when I first tried it. I put it back in its box which it was sent in, …
... by a DC-DC converter that uses TR4 and TR5. If you can ...
