-
Spectrum preservation/clean up questions.I’m sorting out my 5 Spectrums trying to make them look a bit better, and to package them up how they should be, and to get them to be reliable…
... part of the voltage generation circuitry for the lower RAM.
128K models use 4164/4464 RAM which only needs the +5v ... -
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. …
... ).
Zorn's RAM replacement module only uses +5V ... "lower RAM" sockets if the Spectrums on-board voltage inverter circuit ... is working correctly. Although Zorn's RAM ... +12V supply. Without this voltage, it will not work.
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. …
... ).
Zorn's RAM replacement module only uses +5V ... "lower RAM" sockets if the Spectrums on-board voltage inverter circuit ... is working correctly. Although Zorn's RAM ... +12V supply. Without this voltage, it will not work.
48K Upper memory issues?Having more issues with the 48K spectrum I just fixed that had the black screen in this thread [URL="http://www.worldofspectrum.org/forums/showthread…
... Spectrum :)
Often the voltage from modern audio outputs is ... any of the suspect "upper" RAM if the ROM's memory ...ZX81 Power SupplyI have a ZX81 with the original 0.7A power supply. I know that this has trouble running many add-ons and was seeking advice on a suitable replacement…
... power unit with an output voltage of between 8V and 9 ... DC supply with an output voltage of between 8V and 10V ... ZX81, ZX Printer and 16k RAM pack.
What were ...48K Upper memory issues?Having more issues with the 48K spectrum I just fixed that had the black screen in this thread [URL="http://www.worldofspectrum.org/forums/showthread…
... faulty.
Replaced 5V Regulator, TR4 & TR5. Also the ... the screen. Replaced faulty Lower Ram IC (IC8)
Now black ... put in on the lower ram chips were not making good ...Switched voltage regulatorIn the past a replacement voor the (hot!) 7805 has popped up a couple of times in various threads. As far as I know, Recom Power Inc. was always ment…
... need to drop as much voltage :)
B[/QUOTE]
regulator mounted on an external heat ...Cooking toastrack... the dreaded smellI powered up my Spectrum 128 (heatsink model) yesterday only to see what looked like an out-of-tune picture on the television. I'm using a scart adap…
... 's the job of the regulator to turn this into a ... constant) 5v.
The voltage converter circuit then generates -5v ... 's important that the unregulated voltage is not too high - otherwise ...Newbie with a faultHi all just joined after digging my spectrum out of the loft after 30 years, it was put up there because it had a common fault I remember from back i…
... faulty lower RAM ICs, possibly caused by failure of the voltage converter ...Finally got round to itFinally got round to giving my old speccy a close look. Details 1982 Issue 2 Seriel No 001 196193 Hmm... Followed the initial tests on You tube w…
... the following results.
Voltage Reg, maxed out at 75 ... fail then
Lower ram tested on 200Kohm range
Upper ram socketed
Any ... anyhoo.
Partially socketed RAM sections usually mean the computer ...Finally got round to itFinally got round to giving my old speccy a close look. Details 1982 Issue 2 Seriel No 001 196193 Hmm... Followed the initial tests on You tube w…
... through to 26, all upper RAM (IC15-IC22). IC5 (ROM) was ... />
I'd change the regulator, perform the resistance checks again ...Zx spectrum 48+ help pleaseI have just had a look at my spectrum 48+ and I get this [IMG]http://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xfa1/v/t34.0-12/10965632_101526175830…
... most common fault of lower RAM not working properly. This could ... more faulty lower RAM ICs or because the voltage converter circuit has ... voltages at one of the RAM ICs. You'll find the ...The Spectrum Resuscitation ThreadKicking off this thread as a place where people who are fixing/restoring Spectrums (or indeed any other piece of related hardware) can show off their…
... is that the regulator has to dissipate this extra voltage as heat ... 2 amps. This way, the regulator don't have to work ...The Spectrum Resuscitation ThreadKicking off this thread as a place where people who are fixing/restoring Spectrums (or indeed any other piece of related hardware) can show off their…
... version to replace the upper RAM. If you've done all ... switch mode regulator -220mA (400mA)
- with Lower RAM module -105mA (295mA ... )
- with Upper RAM module -35mA (260mA)
- with ...Zx spectrum 48+ help pleaseI have just had a look at my spectrum 48+ and I get this [IMG]http://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xfa1/v/t34.0-12/10965632_101526175830…
... spectrum and tested the voltage at the 4116 ram chip
ram chip that balford was talking ...TR4/TR5 replacementHi guys, I've got another Spectrum I'm working on now - an Issue 4S this time. When I originally got it, I powered it up and did the basic tests a…
... overloading the output of the voltage converter circuit (most likely a ... without removing all the lower RAM IC's (they're not ...You get what you pay for-You live and learnDecided to try for a cheap spectrum + on ebay described as not being able to tune it and some keys did not work - haha Duly received and opened up a…
... ram ?, voltages seem to be showing the correct voltages on the regulator ... and lower ram.
Not even ...You get what you pay for-You live and learnDecided to try for a cheap spectrum + on ebay described as not being able to tune it and some keys did not work - haha Duly received and opened up a…
... is most likely a lower RAM fault, but if the border ... /> [B]Voltages[/B]
Regulator
IN 10.07 V ... V
[B]LOWER RAM[/B]
O V - 0 ...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…
Hello!Voltage on pin 6 is 2. ... the sockets (for the 4116 RAM chips) and 0V/GND (pin ...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…
Hello!Voltage on pin 6 is 2. ... ULA is high. Check the voltage at Pin28. I suppose almost ... the sockets of the lower RAM (IC16-IC22)? Check the sockets ...48k issuesThe 48k speccy had several alterations ( issues) and I was wondering, they all seam to work ok so what was the point?<br>
... boards.
Including all the RAM on a single board drove ... better placement of the 7805 regulator (better larger heatsink) drove the ...Features that are still wanted in Spectrum emulation.Features that are still wanted in Spectrum emulation. 4 USB joystick/gamepad input for real multiplayer games - Yes, Bomb Munchies.... - Sinclair 12…
... an unusual approach of pumping voltage into the ground pins of ... Kempston and a single-joystick Ram Electronics interface, and I suspect ... four separate one meg external RAM packs to it, but you ... of a load of faulty RAM chips is another matter entirely ...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] …
... completely failed or missing lower RAM and that's not surprising ... possible other components in the voltage converter circuit have failed, though ... voltages presented to the lower RAM ICs, it's quite ... quite possible a failed lower RAM IC or a dead electrolytic ...another non working issue 3 48kHi all, next! :) I don't have good filings about this speccy :) https://youtu.be/D9qpCR18-kI here is short video what this speccy do. we hav…
What voltage do you get on the +9V line (test on the input pin to the 7805 regulator)?
What is the actual +12V line voltage?
What is the actual -5V line voltage?
[b][i]Mark[/i][/b]Grey +2 - DOA and no power lightTook a punt on a grey +2 at the weekend to be a spare. It was "untested" although so were all my other +2's which are all fine. Tried to power th…
... amp...
If the voltage on the +5V did not ... /> I trust that the new regulator is attached to it's ... sign of life, record the voltage on each pin of the ...Grey +2 - DOA and no power lightTook a punt on a grey +2 at the weekend to be a spare. It was "untested" although so were all my other +2's which are all fine. Tried to power th…
Probably two issues here - dead RAM (IC27) and possibly the +12v ... be booting with the dead RAM.
To verify if ... /TR9 need attention, check the voltage on pin 11 of the ...Dead SpectrumHello guys, I've just bought a dead Speccy 48k (Rubber Keyboard Issue 3 board). Basically, when powered on it initially appears to boot up ok, but in…
... all the lower RAM chips give the correct voltage readings, then the ... in a lower or upper RAM IC.
Since it ... assume that it's a RAM fault for now. Can you ...ZX Spectrum issue 2 has only blue tintsRecently I've bought a 16k speccy and ran into some issues with it. Faulty keyboard, broken caps, no stable frequency, faulty lower RAM chip, it bein…
... failed.
Check the voltage on pin 8 of IC13 ... a related component of the voltage conversion circuitry has failed, and ... as damage to the lower RAM could result...
BAccess to ZX81-Service ManualI need the ZX81-Service manual to repair my sick Zeddy. Unfortunately I don't get access to WOS documents via ftp. How can I register? For the ZX-S…
... in a known working 16k RAM pack, as this disables the ... you 16k of on board RAM. Some pin rewiring is needed ... the +5V supply from the regulator is okay ;-) ).
I ...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 …
... with glued plastic. The LM317T regulator swivelled round loosely on the ... drives were 40T and the RAM v2.2 .
The ...
