The second of the ZX Spectrums I got recently, which is motherboard only, gave absolutely nothing on the screen
Replaced the usual ZTX650 for a ZTX651 and the one next to it which is a ZTX213.
This one also had the capacitor above them missing. Replaced this for a 4.7uF 50v one and tested.
All working again
I dumped the 4 PAL16L8s from Op Wolf this morning.
I haven’t yet had this board up and running so these are untested. If someone could verify these for me I would be most grateful.
EDIT: Tested these now and they seem to work fine
They are:
B20-09.IC19
B20-10.IC84
B20-11.IC85
B20-12.IC92
Today sees the release of a new C64 game. A fantastic conversion of Prince of Persia.
The game looks and plays just like the original versions across various other platforms.
This game requires an EasyFlash (or compatible) device to run. Naturally it also runs on VICE and most likely other C64 emulators, it also works on a C128.
Swoop on over to CSDb to download it
There is a very simple mod that you can do to bypass the RF modulator and use the same connector for a composite output.
It takes a few minutes to do this and works really well.
First job, remove the lid on the RF modulator.
There is a resistor connected to the centre pin of the RF output socket, remove this and bend it up out of the way.
On the outside of the RF module there are 2 wires leading from the modulator to the PCB. These are the VIDEO IN on the left and +5v on the right.
Remove both of these from the PCB.
There is a second insulated hole in the the side of the modulator unit that is unused. Get some wire and strip enough insulation off the end so you can feed it through and then solder it onto the centre pin that the resistor was originally connected to.
As im never going to be using the RF again I went ahead and totally removed the old VIDEO IN and +5v wires. I also removed the old resistor. This step isnt necessary but if you leave them in make sure they are insulated so they can short against anything.
Fire it up and check out the Spectrumy goodness.
Got myself a broken ZX the other day and it arrived with a spare motherboard. The spare is a later revision so I started with that one.
This is my first Spectrum repair so was a little unsure where to start.
This started up with garbage on the screen in the form of many vertical lines.
As the Z80 was socketed I tested that. Failed and replaced.
Looking around the board I saw a transistor that was a little damaged. Removed TR4 and it was shorted internally. It is a ZTX650. I robbed one off the other board and fitted it.
The Spectrum now works but the picture is really really bad quality.
The keyboard also doesn’t function properly, half of the keys don’t work. Ive read the keyboard membranes are usually shot so ill have to order one up.