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Faulty ZX Spectrum 48kHi guys, I just got around to doing a composite mod on an old ZX Spectrum 48k that I got from Ebay a while back. It did say it was untested and b…
... ). I am sure that the DC-DC converter doesn't work at all ... a high chance that the TR4 has been "cooked". It is ... -
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 …
... 't normally die when TR4 and/or TR5 die, as the 7805 ... are off.
TR4, TR5, the coil (actually a transformer) and associated ... -
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 ... /08/"]blog[/url] about the DC-DC modifications?
[b][i ... -
tr1-2-3-4-5hi guys, can someone tell me, what is the exact function of each of the five transistors i have on my zx+3 i mean the black transistors TR1 TR2 TR3 T…
hi guys,
can someone tell me,
what is the exact function of each of the five
transistors i have on my zx+3
i mean the black transistors TR1
TR2 TR3 TR4 TR5,
thanx, -
ZX Spectrum + Issue 6A Repair attemptHello everybody! I got ZX Spectrum + which doesnt work properly. On power up I can see color mosaic, then paper goes black and i can see thin red ba…
... are good (i replaced LM7805,TR4,TR5), so I suspect upper memory ... -
R-785.0-1.0 5v 1A DC-DC converter Group Order.As discussed in the other thread there seems to be interest in getting a consignment of these devices. I can get 50 @ [strike]?4.40[/strike] and pos…
As discussed in the other thread there seems to be interest in getting a consignment of these devices.
I can get 50 @ [strike]?4.40[/strike] and post them out to people.
who would be interested in buying some? These are the 1 Amp ... -
ZX Spectrum not working... issue 4S?Hi, I've bought a "new" broken ZX Spectrum +. The idea was to put an harlequin board inside, but for the moment I'm trying to put it in working order…
... I'll try first changing TR4, TR5, C44 and C45 (as suggested ... -
Need some advice about electronicsI have wired up an ATX power supply to power my spectrums through a DC-DC converter that gives 9V from the +12V rail. It works well. However, I also …
... power my spectrums through a DC-DC converter that gives 9V from the ... -
Using an ATX power supply - Spectrum 48kOK... I have an Issue 3 48K model and the DC-DC converter does not work and I can?t make it work. :( There is a MOD to use an ATX power supply on the…
... 3 48K model and the DC-DC converter does not work and I ... -
Issue 3 power problemHi all, I have an issue 3 board with an odd power problem, I have no -5V in fact, measuring the voltage on this line leads to a surprising result : …
... are dead, and have replaced TR4 & TR5, as faulty RAM can ... .
It think the TR4/TR5/L3 circuit must be working ... -
12V -> 9VI found this simple dc-dc converter: [url]http://www.mcrent.com/workbench/dcdc1216/[/url] it converts 12V to 16V, can it be used to produce 9V by mod…
I found this simple dc-dc converter:
[url]http://www.mcrent.com/workbench/dcdc1216/[/url]
it converts 12V to 16V, can it be used to produce 9V by modifying R1 and R2?
is there some better solution? -
Project #1 : Speccy 128k+2 with diVide inside...Hi guys, I just have finished my Super Spectrum #1 The idea (I was thinking of that since 2007) was to fit an english grey +2 motherboard in a +2A…
... out), and to refit the TR4, TR5 and TR7 (2N3904) the right ... -
+2 Grey video issueSo far ive replaced TR4, TR5 (and correctly orientated them) and seperated the audio from the video, still I have this; [youtube]mZZWOXRs_Zk[/youtube…
So far ive replaced TR4, TR5 (and correctly orientated them) and seperated the audio from the video, still I have this;
[youtube]mZZWOXRs_Zk[/youtube]
I just know im really close with this but unsure how to further proceed! -
48K misplaced coloursHello to everybody! Slowly recapping a otherwise working Issue 6A 48K. All new caps aroud LM1889, 7805 and DC-DC converter, which improved ripple an…
... caps aroud LM1889, 7805 and DC-DC converter, which improved ripple and noise ... -
Issue 2 Spectrum - Black screenHi I have an issue 2 spectrum which I'm having some issues with. I bought it on ebay so have no idea of the history or how it came to be broken. Whe…
... fine but TR4 was faulty.
I replaced TR4 & TR5 and replaced ... -
48K No Sound?Repaired a 48K spectrum the other day that had the wrong PSU Plugged into it. Replaced 5v regulator, TR4, TR5 and all Electrolytic Caps. Spectrum th…
I broke my 48k Speccy!!!!Hey guys, I am looking for some advice, I hope you can point me in the right direction. So, I went about replacing all the capacitors on my issue 4…
... checked the voltage regulator, TR4 and TR5 and as far as I ... />
I have noticed that TR4, TR5 and C74, C46 are getting ... 45 secs. I checked TR4 and TR5 and they are still ok ...Harlequin Rev. G - error of labels at J16Hi, a German user found an error at Harlequin Rev.G board regarding the labels of J16. The labels of -5V and +12V are interchanged! That could be …
... dangerous, if anyone connects a DC-DC-converter to J16 and plugs in ...Unresponsive Spectrum with Magenta border.This Spectrum is taking an age for me to repair, thank for all the help thus far! So after I switch on the ZX Spectrum+ I get the familiar white…
... .net/LRR/ along with TR4 & TR5 and for good measure I ...Issue 4A, tests complete fine but get odd crashing problemHi all, I've got an issue 4A which has had all of its lower RAM replaced, TR4, TR5 as well as its CPU. It originally had quite high voltages (20-3…
... of its lower RAM replaced, TR4, TR5 as well as its CPU ... some very questionable RAM. TR4 and TR5 were replaced and with new ...What are the chances?Hi all, I've picked up an issue 3B, fairly clean board, no mods, wasn't starting correctly so I tried Brendan's diagnostic ROM and got this: [i…
... it made no difference. Checked TR4/TR5 and they appear OK. -5 ...Issue 2 48k Yellow DisplayHi guys. As the title says, I have an issue 2 that's displaying the typical yellow/green colour screen at switch on. The picture is clear and stab…
... in the correct polarity.
TR4 TR5 removed, checked tested good, refitted ...Issue 2 48k Yellow DisplayHi guys. As the title says, I have an issue 2 that's displaying the typical yellow/green colour screen at switch on. The picture is clear and stab…
... in the correct polarity.
TR4 TR5 removed, checked tested good, refitted ...Timex Computer 2048 restoration projectHi All, I would like to share with you my restoration project of a broken TC2048. Make the story shorty it was my first computer in late eighties …
... the voltage regulator with a DC-DC converter and re-capped the unit ...+2/+3 replacement power supplyI'm getting a black keyboarded +2, it has no power supply so I'm trying to source a possible equivalent if i cant get a genuine one, I know an atx s…
... -12V-suply-Q-60B-ac-dc-converter-good/1981293734.html?spm=2114 ... -12V-suply-Q-60B-ac-dc-converter-good/1981293734.html?spm=2114 ...Modifying a speccy to +5v only operation.Just a thought experiment so far. Let's say i wanted to make a more resilient spectrum by getting rid of the DC-DC converter circuit. This would remo…
... by getting rid of the DC-DC converter circuit. This would remove the ... upper pin 22/23 (12v DC / 12v AC).
I would ...Want a Speccy Repaired?Maybe it's time to put my 'skills' to use.... Now that I've sourced some of the nastier transistors, I've fixed about 6 rubber keyed Speccys in the …
... />
Incidentally, anyone looking for TR4/TR5/TR6:
[url="http://www ...Spectrum Issues by Serial?Wotcher all, Just wondering, as I gaze idly at my newly bought off eBay Spectrum+... is there any way of telling from the serial number what issue a…
... voltage fluctuation and boom goes TR4/TR5.
Of course you ...Tomb Raider - LegendSeven and a half hours. Seven and a half bloody hours. Seven hours and a tad over thirty mins TOTAL. Great Graphics. Great Story. A GRAND TOTAL …
... , the TR3, then TR1, then TR4, TR5 I found a waste of ... /> Mind you if you completed TR5 in under 4 hours; probaly ...48K power supply coilHi guys, been thinking about making a small quantity of PSU coils for the original 16/48K machines. My problem is, although I can (and have, with gr…
That whole part of the circuit is there just to generate the -VE supply for the memory, right? - Why not do away with it completely and use a more modern dc-dc converter module?
MikeW
