The Sinclair QL Forum

Anywhere there is hand soldering I always suspect first so I pulled out the 8302 to see what would happen with it missing. From a quick scan of the documentation it looked like it wasn't involved with the display. It totally changed the screen from a plain pale green to columns of predominantly whit...

Or find a sucker I mean a nice person with a working one that will let me take it apart. :lol: If I bought a working one I could put the other in the bin and then what would I tinker with? I could still do some tests like check if the processor is running correctly by getting it to do something I co...

Have you tested the plugin chips: 8301, 8302, 8049, 68008. Your problem could the 8301 not working correctly. How do I test those chips. :? They want £17 for a x8301 on EBay & sellmyretro. :o Have you removed and re-seated the chips as said above? Yes as in the last post on the previous page bu...

There is a half inch black band at the bottom of the pictures so the bottom should be straight seen better in the Bootup one but the camera angle makes it look curved. It is not so easy to take a picture and hold the button at the same time. The scan lines can be ignored because they varied with the...

I am starting to wonder if it stopped working and that is why I stopped using it since I usually run things until they break and can't be fixed any more.

You really need to have a look inside. First thing to check is IC sockets - contact between sockets and ICs gets worse because of time and corrosion - simply remove and re-seat the socketed ICs. It looks like it has just come out of the factory but I jiggled the chips about that sit in sockets and ...

I checked the supply with a scope and on the output pins there is a 44V AC wave and 10.8V DC so could it be the 9V supply that is causing the problem? I would have thought the regulator for 5V could take a minimum of 12V input since many handle up to 35V. Having opened the supply and put it back tog...

No circuit in the service manual. :roll: I have opened it and it looks weird. :? An SCR and two diodes stuck on windings opposite to the main PCB what is it all about. The caps are not blown or shorted. There seems to be 10.75V on each cap & between two pins on the power lead but the 44V AC is r...

No, that's a fairly late one. It started with D02-XXXXXX That is good it will have less bugs & mods then. :) Unfortunately I plugged it in, tuned the TV in to what looked like a computer screen but it was a sparkly green interference screen not changing when buttons were pressed. Um! I think th...

Is my QL one of the early ones with a serial number of D14 071480? I assume 71480 is the number built but how many were built by the time production stopped? If it is an early one does that mean I need to do mods on it? I don't remember there being any problems with it when I used it in fact compare...