Canon MP970 logic board repair?

[jumperger]

Hi tothe forum,
I found you yesterday and it seems that there a lot of people with alot of knowledge here.
I have a family's membre MP970 here.
The printer wasn't in use for several monthes due to an ink error (low ink I think) and due to illness of the owner.
Now new 3-party ink tanks where added for the as empty marked tanks.
After this replacement the printer stoped working. No sign of life.
Then it came to me.
I've checked the power-supply and found normal stand-by voltages. 7.5V and 9.9V

I managed to get the tanks out of the printer and also took the printhead out.
Plugging it in without tanks and printhead -> No Sign Of Life :-(

From the service manual I read that it might be a faulty logicboard and from the forum I know that a dead printerhaed may burn the logic-board.

Parts catalog lists these items:
printerhead QY6-0062-010 goggle price +/- 180€
Logicborad QM3-2237-000 goggle price +/- 200€

My question to the forum:
Does anybody know a way to troubleshoot or repair test the logicboard ?
regards
Jack

 

[PeterBJ]

Canon print heads can fail electronically for no apparent reason. One type of electronic failure is a short circuit of some part of the print head electronics. A such short circuit will prevent the printer from turning on, see this. If you disassemble the printer partly and remove the print head and the printer will now turn on after reassembly with an error message, the print head is defective. If the printer will not turn on now the logic board and/or the power supply is defective.

The sad thing is that a print head that has been damaged this way might damage the logic board and a logic board that has been damaged by a defective print head can damage a new print head. The damaged logic board might be a print head killer even if the printer gives no error messages. So replacing a print head in this case is a gamble for which I do not know the odds.

If you insert a new or at least known good print head in the printer and it works perfectly, you know the logic board is OK, but this test is high risk and not recommended. Sadly I know no safe method of testing a suspect logic board.

If you want to search for parts the logic board part number is QM3-2237-000 and the print head is QY6-0062-010. But I think the parts will be hard to find and very expensive if available. Beware of "refurbished" print heads from the Far East, they might be defective print heads cleaned to look like new and packed in counterfeit plastic/aluminium bags and cardboard boxes, to look like new OEM

Sadly I think the printer should be considered a write off.

 

[jumperger]

So there is no hope for a blown fuse on the logicboard that could be repaired?
Do you know if the logicboard and printerhead of an other Canon would fit into the 970?
I would keep the possibility to scan old foto films

 

[PeterBJ]

Sadly there is no simple repair for the logic board. Logic boards are specific to the printer model, so a logic board for another printer model cannot be used. Only the QY6-0062 print head can be used in this printer.

Depending on your quality demands a simple film scanner might be sufficient. Aldi DK offered a such scanner a week or two ago. The price was around DKK 300 = € 40. If your photos were taken using a top quality camera and you want a top quality scan, you will probably want a dedicated high end film scanner in stead of a printer/scanner.

If you start a new thread about film scanning in the "Everything Else" forum you might get some tips and recommendations.