-
Multiface 128 problemHello everyone i have a 48k plus speccy which i firstly thought was working perfectly. It passed all the test of the official Sinclair test tape (cpu…
... whole circuit with a small DC-DC converter module?
MikeW -
problem with sinclair zx 48 issue 6aHi all, I have the following problem when I turn on my sinclair without rom inserted. [url]http://217.79.64.145/sinclair/5.jpg[/url] when I turn o…
... wrong. I would check/replace TR4, TR5 and TR3.
-Check IC1 ... -
problem with sinclair zx 48 issue 6aHi all, I have the following problem when I turn on my sinclair without rom inserted. [url]http://217.79.64.145/sinclair/5.jpg[/url] when I turn o…
... /> I will replace tr3, tr4, and tr5 if anyone tells which modern ... can use.
tr3 =
tr4 =
tr5 =
Greets,
problem with sinclair zx 48 issue 6aHi all, I have the following problem when I turn on my sinclair without rom inserted. [url]http://217.79.64.145/sinclair/5.jpg[/url] when I turn o…
... /> I will replace tr3, tr4, and tr5 if anyone tells which modern ... can use.
tr3 =
tr4 =
tr5 =
Greets,
Interface 1 electrolytic capacitorsInterface 1 has three 47μF electrolytic capacitors. Is it necesary to replace them with fresh ones? I always do this with old speccys but is it…
... Speccy are those from the DC-DC converter. I'm still using my ...Interface 1 electrolytic capacitorsInterface 1 has three 47μF electrolytic capacitors. Is it necesary to replace them with fresh ones? I always do this with old speccys but is it…
... ...:D).
Not only the DC-DC converter capacitors, i replace all electrolytic ...Interface 1 electrolytic capacitorsInterface 1 has three 47μF electrolytic capacitors. Is it necesary to replace them with fresh ones? I always do this with old speccys but is it…
... ...:D).
Not only the DC-DC converter capacitors, i replace all electrolytic ...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…
... transistors TR1
TR2 TR3 TR4 TR5,
thanx,[/QUOTE]
TR4 -> Audio IN Amplifier
TR5 -> Audio OUT ...Replacement loudspeaker for rubber key 48kI'm fixing one of my rubber key 48k. Just ordered a membrane for it but I also need to find a replacement loudspeaker for it. The original some how q…
... 't resistance, the DC resistance of the coil in a loudspeaker will ... size of the Spectrum's coil it can't be more ... sure!)
Measuring the DC resistance of a Spectrum speaker ... for all intents and purposes, DC resistance does equal impedance in ...Replacement loudspeaker for rubber key 48kI'm fixing one of my rubber key 48k. Just ordered a membrane for it but I also need to find a replacement loudspeaker for it. The original some how q…
... 't resistance, the DC resistance of the coil in a loudspeaker will ... size of the Spectrum's coil it can't be more ... sure!)
Measuring the DC resistance of a Spectrum speaker ... for all intents and purposes, DC resistance does equal impedance in ...Replacement loudspeaker for rubber key 48kI'm fixing one of my rubber key 48k. Just ordered a membrane for it but I also need to find a replacement loudspeaker for it. The original some how q…
... 't resistance, the DC resistance of the coil in a loudspeaker will ... size of the Spectrum's coil it can't be more ... sure!)
Measuring the DC resistance of a Spectrum speaker ... for all intents and purposes, DC resistance does equal impedance in ...128k heat sink - ULA problems and a hintHello, I had two ZX Spectrum 128k with a similar behaviour. One item worked only a short time after switching on and then there were increasing RAM …
Wow, I didn't know about that little DC-DC converter module. Personally, I'd still make my own module because I have the kit to do it, but if you can't do your own SMD stuff that looks like the way to go.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, …
... maybe have a problem with TR4&TR5 and your Spectrum doesn ...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, …
... maybe have a problem with TR4&TR5 and your Spectrum doesn ...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, …
... maybe have a problem with TR4&TR5 and your Spectrum doesn ...Spectrum 48k Fault - anybody seen this before?Hello, I have two 48k spectrums that exhibit the same fault. Black border, paper area is full of columns of wavey lines. I have posted a screen sho…
Thanks guys. I checked my voltages and am missing the +12 and -5. I've ordered some new transistors for TR4 & TR5 and some 4116 DRAMS.
When they arrive I'll follow the repair guide to see if I can get it working again.Diagnosing Spectrum 48k (faulty RAM chip?)I have a Spectrum 48k (I believe it may be an upgraded 16k model) that doesn't work, and never has ever since the owner gave it to me. When you turn …
... transistor closest to the DC input socket (TR5), when the components are ...ZX Spectrum Power SupplyHi All, I've come across a power supply that is currently registering 14.5v before it is plugged into the Speccy. I have another one that registers…
... excessive voltages will destroy the DC-DC section which runs off the ... direct +12 supply or another DC-DC converter Or create some horrendous /YUV ...Spectrum 48K with a thyristor PSU possible?Is it posssible to use a Spectrum 48K with a thyristor switched PSU? I have a PSU with a thyristor, 4 diodes, one electrolyt capacitor, some resistor…
... the schematic for a small DC/DC-converter.
Not to be confused ...Someone can help me to fix my Zx Spectrum?I did a video about the startup: [url]http://dl.dropbox.com/u/1566495/ZXSPECTRUM03.mp4[/url] I have replaced the ULA with a working one (same proble…
... power circuits around TR4/TR5. A common fault is TR4 (ZTX650) - this poor ...Someone can help me to fix my Zx Spectrum?I did a video about the startup: [url]http://dl.dropbox.com/u/1566495/ZXSPECTRUM03.mp4[/url] I have replaced the ULA with a working one (same proble…
[QUOTE=gibs;431121]... 4/ how to check TR4/TR5 ?[/QUOTE]
When -5V and +12V (at 4116) are present then both transistors work OK. So you checked already.Where is the other side from the ZX 48 PCB?Has anyone the other side from the PCB? [url]ftp://ftp.worldofspectrum.org/pub/sinclair/technical-docs/ZXSpectrumIssue3-PCB_Bottom.gif[/url] Micky
... , and a YPrPb to RGB converter instead of noisy composite video ... two things would render the DC-DC converter useless and simplify the overall ...damaged spectrum+ (blinking squares)Hi, Sorry for my poor english, but I couldn't find on family forums any remedy for my hardware problem with my first speccy in my life :) I've bought…
... ZX Spectrums, usual suspects are TR5 and (especially, since it is ... doing a tough job) TR4. Often followed by a failure ... bad news: finding replacements for TR4, TR5 or 4116 DRAMs may not ...damaged spectrum+ (blinking squares)Hi, Sorry for my poor english, but I couldn't find on family forums any remedy for my hardware problem with my first speccy in my life :) I've bought…
As roko said: if those voltage readings are correct, TR4/TR5 are fine - leave them alone.damaged spectrum+ (blinking squares)Hi, Sorry for my poor english, but I couldn't find on family forums any remedy for my hardware problem with my first speccy in my life :) I've bought…
... bad news: finding replacements for TR4, TR5 or 4116 DRAMs may not ... production transistors that can replace TR4 and TR5, you don't need ...7805 Regulator HelpI am hoping to replace the 7805 regulator in my issue 3 48K Spectrum soon. Unfortunately I don't know exactly what to buy to replace it with (my fat…
... ]
It is a DC - DC Converter. A transformator is AC - AC ...Do ULAs die?Thought I'd start this thread as people often think their ULA is dead, when it's actually the RAM or power circuits. Searching the forum in the futur…
... all transistors in the switching dc/dc converter. The 4116's survived, as ...Was the +3 a missed opportunity?I just wanted to gauge WOS opinion on this. Do people think that the +3 was a bit of disappointment that didn't really advance the hardware as much a…
... and chuck in a proper DC-DC converter module for the 12v needed ...
