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Black paper, white border. Ram fault?We have a speccy that wont work properly. When we power it up, we get white border around a black screen. We swapped the rom and ula with a working o…
... 'd start by checking the voltages on the 4116 RAM first ... -
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 …
... to check if all the voltages are present before the TR4 ... -
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 …
... to check if all the voltages are present before the TR4 ... -
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…
... /> if i have this normal voltages is it true that my ... -
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…
... /> if i have this normal voltages is it true that my ... -
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 …
... 16K of RAM with three voltages, it's likely the short ... -
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 …
... 16K of RAM with three voltages, it's likely the short ... -
Just got a Spectrum +2BThis is the first Spectrum I've ever used or owned. I got it without a video cable or power supply. I wired up a proper video cable, and I altered an…
... , and the computer uses other voltages as per the 48K, directly ... -
Did I killed my Speccy ???Hi guys, 1 minute ago I was working on my 128 +2A... But I made a mistake : I cut the gound on the PSU plug of the computer, and I forgot to resolde…
... 'd also suggest checking the voltages, making sure you still have ... all the right voltages around the place. The RAM ... -
Did I killed my Speccy ???Hi guys, 1 minute ago I was working on my 128 +2A... But I made a mistake : I cut the gound on the PSU plug of the computer, and I forgot to resolde…
... have a look at the voltages...
I tried it ... -
Audio input on a +2would it be possible to connect an external tape recorder to the socket at the back,or would something bad happen?
... of latch up protection, and voltages even a little over Vcc ... -
Zx Spectrum Laptop (again)I've been reading all the old treads about a possible portable speccy. I even found the one about the Speccy Laptop. But it seems there's a lot of ne…
... -pack, and delivers the different voltages you need. The internal power ... heat. It also keeps the voltages steady even if the battery ... -
Zx Spectrum Laptop (again)I've been reading all the old treads about a possible portable speccy. I even found the one about the Speccy Laptop. But it seems there's a lot of ne…
... ) Pilsener), which would yield all voltages needed. Heck, I'd even ... -
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 …
... power supply to produce other voltages: +12v and -5v. The way ... 16, and then check the voltages on 1, 8 and 9 ... hot if you're getting voltages at these pins but somewhat ... -
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 …
... checking that you have the voltages required to run the RAM ... -
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…
... checking that you have the voltages required to run the RAM ... -
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…
... how to easily check the voltages. With any luck, the previous ... , on checking the power supply voltages:
With a multimeter ... power supply to produce other voltages: +12v and -5v. The way ... hot if you're getting voltages at these pins but somewhat ... -
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…
... generates some of the 'weird' voltages (+12v) is a switch mode ... over a wide range of voltages, however, there are certain assumptions ... -
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…
... doublers to get the odd voltages from the 9V supply. Also ... the tracks with potentially destructive voltages are cut, the rest of ... -
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…
... they need three different supply voltages, you also have to turn ... -
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…
... converter that generates those required voltages. He's not got around ... -
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…
... they need three different supply voltages, you also have to turn ... -
TV Modulator. Can it be repaired?Is it possible, to repair tha TV modulator (after removing it) if it gives wavy picture? I replaced both transistors (tr1/2) and both electrolytic ca…
... diagram and a continuity tester. Voltages are perfectly ok, I just ... -
TV Modulator. Can it be repaired?Is it possible, to repair tha TV modulator (after removing it) if it gives wavy picture? I replaced both transistors (tr1/2) and both electrolytic ca…
... diagram and a continuity tester. Voltages are perfectly ok, I just ... -
+3 external floppyI'd like to connect 3,5" PC floppy drive (NEC) to ZX Spectrum +3 (with diode for RDY). Here are questions: 1) It seems the PC floppy uses just +5V, …
... STABILIZER, and gives option of voltages:
1.5-3-4 ... -
+3 external floppyI'd like to connect 3,5" PC floppy drive (NEC) to ZX Spectrum +3 (with diode for RDY). Here are questions: 1) It seems the PC floppy uses just +5V, …
... STABILIZER, and gives option of voltages:
1.5-3-4 ... have not so stable output voltages.
Other (e-bay) source ... -
Dead +2B, help required...It was bought defective on ebay. It came with two faults: a "dead" power supply (it was the fuse) and a faulty main unit. The power supply is now re…
... />
I've already measured voltages on every component. Every IC ... -
Mysteries of Electricity QuizA little fun quiz that I know the answers to, but may lead to some head scratching and disbelief, but there's easy experiments than can be performed …
... change their conductivity at different voltages e.g. metal oxide varistors ... -
On a 48K issue 6A......how can i isolate the 32K block? I want to test if there is any fault on the 4116's , leaving the 4532's out of the equation. Will removing the …
Also test the power supply transistors! Do you have the voltages to run the lower RAM?
Test TR3, that'll make the lower RAM appear dodgy if it's gone.
Test IC28 74LS04 too. -
On a 48K issue 6A......how can i isolate the 32K block? I want to test if there is any fault on the 4116's , leaving the 4532's out of the equation. Will removing the …
... doing its job. Check the voltages are right on lower RAM ... single supply and the supply voltages must all be right.
If those voltages are off (more than 0 ...
