Canon PIXMA MP510: power supply defective or not?

[Ano1]

Hi there,

My Canon PIXMA MP510 does not switch on anymore, nothing happens and no lights.
According to the service manual either the power supply board or the main board/logic board will be defective.
Between the power supply and the main board there is a 5 wire cable. According to the service manual this is the pinout:

J503
1 - Motor power supply, +32V (output)
2,4 - GND
3 - Head power supply, +24V (input)
5 - Power supply control signal (output)

N.B. The cable between power supply and logic board is in mirror view, so 1-2-3-4-5 on one side is 5-4-3-2-1 on the other side.
This is what I measure on the pins of the power supply unit, with the cable disconnected:

1 - 7.5V
3 - 10V
5 - 0V

I looks like the power supply is in "low power mode", because the control signal (pin 5) is 0V.
Any suggestion on how to solve this?

 

[Ano1]

Reading some other forum posts on Canon printer PSU's, I understand I can force the PSU to "normal mode" by applying a voltage to pin 5. So I did that, by bridging pin 3 and pin 5. And yes, normal voltage on pin 1 (32V) and pin 3(24V)! So the power supply must be all right.
But after connecting it again to the logic board: nothing...
So I guess the logic board is the problem. I do not see a possibility to repair this board, furthermore, I read a bad head could have damaged the logic board. So I will put the printer in the garbage now I guess.