I took the back cover plate off on my Canon IPF760, jiggled some wires around and it started. I left the cover plate off in case I need to do it again.
I fixed my iP4500. I think.
I had the same problem as above. My iP4500 is only 18 months old and rarely used, although I leave it on all the time. However, following a power outage, I couldn't get it to turn on. Tried different receptacles, pressing different button sequences, nada. It was dead.
I assumed the power outage had caused a surge, possibly blowing an internal fuse. After reading the posts above, I realized there was no fuse ... and perhaps the power outage had blown a circuit board, meaning the whole printer would be replaced.
I know nothing of electronics or circuitry. But I decided I had nothing to lose ...
I placed the printer standing on its front face (where printed paper comes out) to examine the bottom. I noticed the power cord isn't directly attached -- it is a removable plug which fits on two prongs mounted on the printer. I removed the power cord, then noticed the prongs are seated in what appears to be a separate module. Turns out, this module can be easily removed -- pressing in just two plastic tabs will release it. However, it now remains attached to the printer by a white plastic slide-on connector holding four colored wires. This white connector plug is easily disconnected, and the box-shaped module is now free. It measures about 6" by 2" by 2".
On the cover you will see a small silver hex-head screw. You will need a #4 mm hex socket to unscrew it. I used a screwdriver as a wedge to pry up this cover where it is seated on the other side. Out came the circuit board ...
I didn't see any burn marks or damaged-looking components on the circuit board. And since I come from the old school of "take it apart and put it back together to see if it works," I decided to fool around.
I directly re-connected the circuit board to the dangling white connector hanging from the printer. Then I re-attached the female end of the power cord to the two prongs. Next I plugged in the power wire to a receptacle ... then hit the ON button.
Voila! The power light came on and the printer started making noises. I immediately shut it down, then re-assembled the module and re-installed it in the printer. I then took the printer to my computer, reattached the USB wire, plugged in the power cord and turned it on again. After the usual warm-up noises, the thing is printing perfectly again.
I honestly have no idea if I actually "fixed" anything. Perhaps the power cord was loose from the prongs, or perhaps the wire connector wasn't seated properly before. But this whole effort took less than 10 minutes, and I can say my printer is now working just fine again. Maybe this will help someone else ..
I have owned at least three i560 printers for around 10 years. I never had an electronics failure until a month ago when all hell broke loose.Another risk is that the logic board can be damaged by a faulty print head. Repairing a Canon is going to be a gamble, neither easy or cheap. I was quite impressed that apart from four screws at the rear the printer body is held together mainly by plastic tabs - easy to take apart if you can find them all without breaking anything. Oh well, you can't win them all.
Does the printer plug directly into the wall, ie - just a wire? Or is there an AC to DC converter in line? If there is a "wall wort" or "brick" on the power line do you have a multimeter to check that it is delivering the correct (or slightly higher) voltage that it says it should.
You sound like someone with good electronics background, so don't be offended by my weird story of getting my Canon MX882 to turn on. Basically, I was making progress resetting the dreaded B200 error. Then for no reason, it did not turn on. I tried various things. no go. I brought it to the trash area, Then one day, I took it into the laundry room and plugged it in to the same outlet as a drier. It turned on! It still is working! I'll let you figure out the electronics!
addition: if I keeping the voltmeter connected the volt level constantly decreasing as if the condensator slowly goes emptyHi there, I just have this problem with my hardly used iP7250!!
I measured 10,7 and 8.7 Volts respectively. I am already confused. So, does it mean that if I measure these values, than my power unit is gone?
I cleaned the ink holders, it didn't help, neither the "reseting" by holding the power button while reattaching to the socket.
anyway, I just checked in Amazon, I would get for +/- 35 euros a power unit, or +/- 70 euros for a new same printer.. the new set of ink just arrived was 75 euros , maybe the less painful solution is to buy a new one.Bang goes my theory that a single function iP7250 unit will be more reliable.