Canon i860 PSU

[mockingbird]

I have here a Canon i860 printer where everything upon inspection seems to be good, the printer has been lightly used, but there is a problem. It won't turn on. The symptom is that when it is pluged into the wall and the power button is pushed, nothing happens. I tried with other proven working power cords.

I removed the modular power supply from the back and cracked it open by dremelling slits in the proprietary screws. Here is what it looks like:


I'll also attach it for the sake of forum archiving.

Now the primary cap is a Rubycon "SXW" 200v 150uF and the tiny one (What I'm assuming is a starter cap) is a Nichicon "PJ" 50V 4.7uF. the two secondaries are 1 large Rubycon "ZL" 35V 680uF and the smaller one is a UCC "LXJ" 35V 330uF. (This is why I love Canon, unlike Nazi Lexmark and Epson they use quality Japanese parts).

Now assuming the caps are ok (Because I can't test them), is there a picofuse of some sort on this PCB which I can check for continuity? If not, should I open the printer up and look for it there? What else can I check?

[MXM]

have you checked the diodes and stuff?? tried to meter the output from this board?? the transistor??

[momaka]

I see the Panasonic [M] logo on the right - was this PSU made by Panasonic? 0.o
Looks very nice and clean.

Anyways, are there any components on the other side of the PCB - perhaps a SMT transistor or IC somewhere on the primary side? By design, I'm guessing it's similar to 5vsb circuits you'd see in PC power supplies - i.e., PSU is likely always on. If there's only output wires (no PS-ON signal), plug it in and check the voltage on the output(s).

[shovenose]

Originally Posted by momaka

I see the Panasonic [M] logo on the right - was this PSU made by Panasonic? 0.o
Looks very nice and clean.

good eye. i would never hav noticed that