The Sinclair QL Forum

my second ql printer has a defective printhead ,

i have assembled and disassembled the thing several times but a good print result is unfortunately not possible .


Is there any member who can share a working printhead ??

I had the same issue a couple of years ago with my 2nd QL printer. In the end I couldn't find a working head so sold it as spares/repairs and kept another QL printer that does work properly. At the time I also tried to find what other models (e.g. Seikosha sp1000/sp800... and maybe others) probably have the same print head, but I wasn't willing to go to the expense of buying random printers and parts and doing all the that leg work - mainly because I had the working one already.

The only replacement will be an old seikosha one from the 800 series , all others is a waste of time.

And of course very few, if any, would have been checked/tested beforehand, so you never know what you're going to get.

The SP800 head is compatible. The flex PCB ribbon is slightly different on some revisions but it is easy to swap them with a soldering and middle school soldering skills. The SP1000 head also works, but the ribbon is longer and always needs swapping. So if you check your flex ribbon is OK before ordering, they are usually a safe bet.

You can run the print head submerged in WD40 to de-gunk it. However, it is critical to degrease it afterwards - I use brake parts cleaner for this - then use some dry lubricant.

i will firstly give it a try to re-assemble the head ( the way i think it should be ) then soak it a couple of days then use plent of brake cleaner to get rid of the wd40 , and when all is clean give it a measure .

right now it is a black stinky block of annoyance .

i already cleaned the printer so that looks new.