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Re: ql printer repair woes

Posted: Sat Feb 20, 2021 10:12 pm
by Dave
I have a spare SP800QL carriage/print head I can send you from Texas, for just cost of shipping. It is fully working. I also have a PCB same situation, and I think a QL-badged case top.

If you have clogged pins and the solenoids aren't wrecked, isopropyl alcohol isn't the way to go. A penetrating oil like PB Blaster is ideal as it dilutes the oil in thinner penetrating oil. WD40 is ok for surface cleaning, but it is very drying so would need to be followed by a penetrating machine oil anyway. The oil needs to be cleaned off afterwards with great care. Any oil left will attract paper fibres and result in a printer jam eventually.

Re: ql printer repair woes

Posted: Sat Feb 20, 2021 10:44 pm
by Chr$
Dave wrote:I have a spare SP800QL carriage/print head I can send you from Texas, for just cost of shipping. It is fully working. I also have a PCB same situation, and I think a QL-badged case top.

If you have clogged pins and the solenoids aren't wrecked, isopropyl alcohol isn't the way to go. A penetrating oil like PB Blaster is ideal as it dilutes the oil in thinner penetrating oil. WD40 is ok for surface cleaning, but it is very drying so would need to be followed by a penetrating machine oil anyway. The oil needs to be cleaned off afterwards with great care. Any oil left will attract paper fibres and result in a printer jam eventually.
That's very kind of you Dave. I will certainly take you up on that - just the head if possible as my carriage seems ok (and to save postage costs).

Your PCB also has the same issue, or same situation as your other items, i.e. working?

I see there is an ebay seller selling NOS TK3L10Z, but I couldn't actually find any short in the 3 on my board and resistances across various combinations of pins were all approx. the same on all 3. There is quite a bit of shoddy soldering on the rest of the board with pins soldered but through-holes still partially holes, but I suppose that's unlikely to be what caused my solenoids to die. And thanks for the oil info.

Re: ql printer repair woes

Posted: Sat Feb 20, 2021 11:01 pm
by Dave
Let me dig it out for you first before anything else.

*digs*
IMG_2339.jpeg
This what you're looking for?

Re: ql printer repair woes

Posted: Sat Feb 20, 2021 11:14 pm
by Chr$
Dave wrote:Let me dig it out for you first before anything else.

*digs*

IMG_2339.jpeg

This what you're looking for?
Yes, looks the same to me.
20210221_001107.jpg
Are the resistances between the centre 3 common connectors and the outer connections to the pins around 32 ohms?

I wouldn't want to fit out without finding the problem on my PCB first though.

Re: ql printer repair woes

Posted: Sat Feb 20, 2021 11:29 pm
by Dave
Three show open, one shows 1.8M, all the rest show 33. Working pull I did a test print on right before taking that pic.

Re: ql printer repair woes

Posted: Sat Feb 20, 2021 11:34 pm
by Chr$
Dave wrote:Working pull I did a test print on right before taking that pic.
That's good enough for me then. I do wonder though if mine may actually be ok (similar results but not quite) and just the board is at fault. Does your spare board function properly?

Re: ql printer repair woes

Posted: Sat Feb 20, 2021 11:55 pm
by Dave
Yes.

Let me dig that out before committing to send it.

Re: ql printer repair woes

Posted: Sun Feb 21, 2021 4:13 pm
by Chr$
Thanks Dave.

I took apart my other fully working QL Printer and the 9 outer pins at the rear of the head were all around 32 ohms to the centre common. Any reading other than that I think must indicate a faulty solenoid.

Now I have a sticky pin (8th down) on the good QL printer! It comes and goes, so this time there is a mechanical stuck issue and nothing more serious but annoying nonetheless as the printer has been fine for well over a year.

Re: ql printer repair woes

Posted: Sun Feb 21, 2021 9:44 pm
by RalfR
Try to print a whole black page, that may work. And you can see, which pins are wrong.

Re: ql printer repair woes

Posted: Sun Feb 21, 2021 11:41 pm
by Chr$
I did some pages in 'Near Letter Quality', wow, you should see it 8-) . And it seems to be behaving itself now, all pins firing (in the working printer, I still have the non working one with broken head and possibly PCB).