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Bad (new) 100uF caps causing video disturbanceJust to let you know about one of my small experiences: I had a couple of 48K boards I was refurbishing: new electrolytic caps, composite video, te…
... boards nowadays.
But after replacing them, I got disturbance in ... , maybe some part in the power circuit.
But when testing the ... -
Issue 3 /3b power rail improvements<!--[if gte mso 9]><xml> <o:OfficeDocumentSettings> <o:AllowPNG/> </o:OfficeDocumentSettings> </xml><![endif]--> <p class="MsoNormal">Hi F…
... added components
to the power circuit on these machines, an extra ... /> The changes must improve to power rails around the pcb and ... -
toasted soeccysHello, ive jsut bought a pair of speccys on ebay (one 16k issue 2 & a prob 48k issue 3) unfortunaly the genius who sold them tried to see if the wor…
... Issue 2 suggests that the power supply that generates some of ... (+12v) is a switch mode power supply, which gets regulated by ... -
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 …
...
Sounds like the power circuit is uh.. "Failed Under Continuous ... your problems. The power supply circuit is probably not ... RAM chips until the power circuit is confirmed working again, ... in the power supply circuit (these probably need replacing in your ... -
Issue 2 Spectrum overheating keyboard membraneI think I have an issue 2 ZX Spectrum. I don't want to take it apart again as I had problems replacing the keyboard membrane. With Interface 1 conne…
... regulator circuit around TR4/5 (not sure about the later issues). Replacing ... I might just consider replacing the entire internal power circuit with a more ... reduce the power burden of the overall circuit, e.g. by replacing DRAM ... -
try to fix issue 4 board problemHi I try to fix speccy 48. All voltages are in place, ula 100% ok, cutted +5v from ic25 so far no luck. What next? ROM or upper memory? wojtek (i…
... the ZTX650 in the power circuit that needed replacing... I did replace a ... -
128K heatsink no color in composite video and bad antenna outputI am currently repairing a ZX Spectrum 128K heatsink model. It gives no colors on composite video output, and very bad antenna output. I opened it a…
... - replacing the TEA2000
- replacing the ULA
- disconnecting the composite video circuit ... the modulator circuit to try composite video alone
- replacing the ... circuits
- replacing the ZTX650 and ZXT213 at the power circuit
- ... -
Faulty 128K toastrack keeps resettingHi. I have this toastrack which worked nicely for let's say 40 minutes and then a weird fault showed up. It keeps resetting over and over, sometimes…
... your voltages out from the power circuit? And have you replaced the ... a problem as simple as replacing the voltage reg up to ... -
DivIDE CompatabilityThe Spectrum is 30 show proved a valuable event for investigating issues with Spectrums which do not work with the DivIDE.... The ones I sell are ma…
Regarding divIDE issues, it would be interesting to take new ZX PCB (why nobody produce them ???) and move components, maybe replacing capacitors and changing power circuit. It will not solve M1 problem, but at least signals should be more stable. -
Difference between brands of 4164 chips?I have gotten my hands on a batch of several brands of 4164 chips. Examples are NEC D4164C-3 and Mitsubishi M5K4164ANP-15. Anyone knows if any type …
... pop, they often take the power circuit with them. Which can take ... may be safe.
Replacing them when they die with ... also doesn't require multiple power supplies is perhaps a good ... -
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'…
... to a failure of the power generation circuitry (you should be ... pin 9).
Usually replacing TR4 (ZTX650) with a ZTX651 ... /3 or equivalent fixes the power circuit, however a failure in one ... -
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'…
... to a failure of the power generation circuitry (you should be ... pin 9).
Usually replacing TR4 (ZTX650) with a ZTX651 ... /3 or equivalent fixes the power circuit, however a failure in one ... would check voltage on the power supply jack, and the current ... -
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…
... one of the above
- Power circuit stops oscillating, blowing TR4
replacing the equivalent transistors on those ... on these 128's a power supply rail gets shorted, blows ... for the +3, presumably the power brick is made of pretty ... -
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…
... , something destroyed the power circuit with the short circuit of the edge connector ... guessing TR4 and TR5 need replacing again? -
Help with 128k greyHello friends, need some help here on try fixing a +2 grey spectrum128. To keep it short, opened the case and the voltage regulator was missing, the …
... ztx213 and 650 in the power circuit, then z80 was dead and ... -
How can I fix a problematic Retroleum Smart Card. I did not do anything "WRONG " with it but I did but it on a flexible cable and this seems to have "upset" it .Since then It does not perform the …
... was not pulled apart with power on just use with ... broader question is "What power circuit protections can be built into ... protect against the usual interface power (pulled apart with) on ... the ideal level of electrical circuit protection for interfaces like ... -
48K Issue 3B slowly fading over 15-20 seconds, capacitor gets hot.Hi folks, Recently my much-modified* RAM testing 48K board failed with a hot/burny smell so I turned it off quickly for looking at later. Thinking…
... /> Something's failing in the power circuit and causing a short but ... -
Dead Spectrum +Hi all, I've recently dug out my old Spectrum + with the idea of repairing it. When I last looked at it, when I was much younger, I was soldering a …
... is to check that the power circuits are working correctly. With ... that the rest of the power circuit is working. The Speccy has ... failed RAM rather than failed power circuits. Also, checking the ... components that have failed short-circuit.
There's ... -
toasted soeccysHello, ive jsut bought a pair of speccys on ebay (one 16k issue 2 & a prob 48k issue 3) unfortunaly the genius who sold them tried to see if the wor…
...
Anyway, on checking the power supply voltages:
With ... that the rest of the power circuit is working. The Speccy ... failed RAM rather than failed power circuits. Also, checking the ... components that have failed short-circuit.
There' ... -
Who has an Issue 1 or Issue 2 Spectrum??Do you have an Issue 1 or 2 Spectrum (ie machines with 5C102E and 5C112E ULA's) ??? You're help is needed! PLEASE SEE THIS THREAD: [url]http://www.…
... been caused by a flaky power circuit...
Don't panic ... -
Composite Video output problemHi everyone, I?ve got a problem that?s really bugging me. I have one Spectrum 48K and one Spectrum +3, both with Composite Video output modification…
... drive the speaker and the power regenerator circuit. It is pushed through ... .
Either your power circuit (check circuit diagrams available on WoS archives ... doing strange things to the power circuit.
I have some ... -
Blown standard divideI recently bought a SIY divide kit from Papaya labs and after i soldered everything, it worked perfectly. I've used it 5-6 times without problems (Fa…
... especially not for burning the power circuit transistor because this transistor is ... -
Blown standard divideI recently bought a SIY divide kit from Papaya labs and after i soldered everything, it worked perfectly. I've used it 5-6 times without problems (Fa…
... especially not for burning the power circuit transistor because this transistor is ... connected a kempston interface (with power off ofcourse).
The ZTX650 ... -
Spectrum ULA replacement!Hi gang.. The Speccy 48 ULA Replacement is *almost* here ;) There has been lots of activity in building the CPLD board, sorting out some irritating…
... break TR4 of the speccy power circuit, and whilst checking the voltages ... -
48K specs boots, but THEN blinking blocks!Of all ZX problems I have seen, the 'blinking blocks' is the most common... Today I picked up a 48K, it boots and THEN it locks filling the screen wi…
Definately check the power circuit outputs (+5v, -5v and +12v).< ... up.
If your power is not stable, then you ... -
Is it possible to use external power supply for +-12; +-5 for ZX SpectrumRecently I acquired a damaged Sinclair ZX Spectrum, issue 3B. According to the maintenance manual I have to replace TR4 and TR5. These type of transi…
The transistors in the power supply aren't particularly critical. ... Spectrum with a huge power transistor in the power circuit instead of the ... to breadboard the Spectrum internal power supply and test its performance ... -
ZXPROJECT update: a replacement for TEA2000Just go to [url]http://www.zxprojects.com[/url]
... transistor belongs to the supply circuit, and it may be related ... /plus2layout.png[/url]
POWER CIRCUIT
[url]http://zxm.speccy ... -
Where's the border line between a Spectrum and something else?I mean: there are purists out there that consider that anything that is not a true Sinclair Spectrum, with a true Z80 and a true ULA, and at most, 48…
... , anyone who has replaced the power circuit, RAM, ROM, Modulator etc in ... -
Help needed +2 pleaseI have a 128k+ that when powered up through the rgb or aerial connection just shows a black screen. But I can still see the list of options and run d…
... , it forms part of the power circuit).
As I said ... -
zx spectrum ULAis the ULA in the 16K the same as in the 48K could you take the 16K ULA and place it in a 48K I ask this because i have a speccy thats dogy with th…
... /> Possible cause TR4 of the power circuit blowing, and taking with it ... connected one up with the power supply completely reversed, and it ... />
You can test the power supply with a multimeter. If ...
