Hardware Printer won't power on, tried everything

Have 'no power' problem with Canon MG5350. Phoned Canon service who told me this wasn't a usual problem... looks to me as if it is! Removed and replaced the white cable holder; printer came on! But with a message saying a problem, to disconnect and contact service centre. Disconnected and it won't come on again. I won't be contacting their service centre and will go for new (I haven't the time to take the machine to pieces)... but a big thank you to everyone on the forum... a great help to someone who has never tried taking a printer to pieces before! Now I need some advice on a new one... will look on the forum.
Same no-power problem as others, on a Canon iP4500.

Removing and reseating white connector on PSU made no difference. Tried this several times.

Applied +5V to yellow PSU cable. PSU voltages good but still will not switch on.

Reassembled and press power button one more time. Printer powers on OK!
Hi: just found this thread and I think I undersytnd why some people get differet voltage readings from the power module, and also why disconnecing it and reconnecting it sometimes cures the "won't start" issue. (I'm an electrical engineer.)

The power module contains capacitors. Capacitors can/will retain a charge unless an external resistive load drains it away. If external logic connected to a power supply with enough capacitance goes into an undefined or lockup state, the charge of the capacitors will maintain that condition even after the mains power is disconnected. Modern logic circuits have VERY low internal resistance, and some components like static RAM don't depend on an external voltage to maintain their memory.

Canon printers with detachable power supplies have no isolation beyween the mains power and the logic circuitry, and on US models, no chassic ground (Canadian models require a grounding connection). That makes their logic circuits susceptible to static discharges and to high ampitude power line voltage spikes of short duration. Knowing thism I connect all my equipment through old school Isobars, which do a good job except for the worst case situtauion: extreme high voltage but low energy line spikes.

I've never had a Canon printer that failed during humid weather except once immediately after a severe thunderstorm. The only lockup I experienced, happened recently when it was cold and very dry. Disconnecting the power module from the chassis and putting both in a high humidity environment for a few hours allowed the internal logic to reset and the capacitors of the power modue to bleed down. After letting both dry out, and resasembling, the printer worked like new.

As far as seeing or not seeing voltages on the connecting conductors between power module and chassis, that would depend on the particular module. A newest generation power modules have some basic logic to limit power consumption when off. Without that logic they would draw current and more current continuously whether or not the always-connected load was "on". The Canon module supplies only one very low amperage output voltage until the load need to draw more power. In Canon printers, the printers sends the power module a wakeup signal telling the power module to provide more current and possibly use other conductors to provides other voltages.

A lot of the vilnerabiolity pf Canon and other appliances to static could be simply elimniated by mandating that grounded power supplies with some high frequncy line noise suppression be provided. That consumers accept logic controlled appliances that have no integral protection from the power grid is due to ignorance encouraged by appliance manufactures and makers of "surge protectors", because both groups benefit from appliance failures due to line issues. Adding individual protection to all equipment when built would increase the unit cost by <5USD and decrease frequency of failure to that of the mechanical components, typically a factor of 3 or more.

BTW, +95% of all surge protectors are ineffective against high voltage low current spikes, and/or have "warranties" that are cost prohibitive and/or impractical to excerize.
6.5 years later and Timroperco's post is still pulling em back from the dead! Cannon MX350 powered up after power bump killed it. Simple disconnnect and reconnect.

Thank you sir, your a gentleman and a scholar.
My Canon Pixma MG6821 printer/copier/scan/fax was waiting to print my last shipping label for the morning when the power failed. We were without power for about 1/2 hr. When the power was restored, the Pixma would not turn on. Only a little orange icon in the right lower corner of the control panel would light, with a little triangle and what looks like a lightning bolt inside it. I could find no information in the operator's manual about what to do when this light comes on.
All my computer equipment is plugged into surge protectors. We have had several outages since I've owned this printer with no problem. Maybe it happened this time because the printer was turned on when the power failed.
I tried unplugging, waiting 3-5 mins then plugging back in. No luck. Pushing the buttons didn't help. Then I searched and found this forum. I tried Timroperco's fix. The MG6821 is configured differently than his machine. Two metal tabs hold the module for the plug. The module pops out if both tabs are pushed correctly. The module is connected to the machine by a band of several tiny yellow wires. I forgot to count how many. The wires go into a white plug inside the module. This white plug is fixed so it will not come out. The two sides of the module are held together using a screw that needs a small hollow hex driver that fits over the screw head. I didn't have that sort of driver and was desperate to get the printer running again.
I pulled very firmly on the little white plug that holds the yellow wires until it seemed to work slightly free from whatever it is connected to inside the module. Then I pressed the white plug in again as hard as I could.
I plugged in the printer and it powered up!! Got my label printed and was SO grateful I had to write this in case anyone else with a similar machine runs into this problem. Thank you Timroperco!
This actually happened again! When I disconnected the module for the power supply, I counted 5 thin yellow wires connecting the module to the printer. The wires go into a brown connector that plugs into a white receptacle on the module. If you pull hard enough, the brown plug pops out with the wires attached. It is a 5-pin plug. Pulling out the plug and then firmly reseating it restores power to the unit.


Posts: 7   +0
I feel kinda stupid. This should be simple.

Yesterday, I quickly "aborted" a print job on my Canon ip4500 usb inkjet printer by pressing the power button on the front of the unit. Now it won't power back on.

The Power button does not appear to be damaged. I've tried plugging the printer in in another room (by itself, no computer) and still nothing. I've also left it unplugged overnight and even tried using a different power cord. It just will not power on. Note, the printer was working just fine yesterday afternoon. The only thing I did was turn it off in mid-operation.

Even if the power button were damaged (and I see no sign that it is), it should turn on by itself when I go to print. Instead, I get an error message simply saying "the printer is not ready." (at first, I was getting a message that "the printer is offline", but I was able to toggle that by going into the Printer Properties in Windows and changing its online status.)

The printer is only slightly over a year old, so it's no longer under warranty (naturally). Newer models are junk, so even though Canon has a "trade-in" program, I'd rather fix this one (which SHOULD be something simple).

I bought the "Canadian" version of this discontinued printer specifically for it's CD printing capabilities. Newer models... and ALL U.S. printers... disable this feature (by law?) According to Canon (after I asked), there is no fuse inside the unit that might have blown.

Does this problem sound familiar to anyone? The cost of taking the printer to a repair shop would cost more than the printer itself, yet finding a decent replacement would be very difficult if not impossible. Help! TIA.
I know this is an OLD OLD post. But in case anyone googles it. When an Epson printer no longer powers on. The main causes are either A, the power supply has died. And they easily remove, or at least in the XP printers anyways. They resemble a laptop power supply, the box part that is.
Or B, the transistors have blown. Now I've had my hands on a fair few give away printers & I've messed around with them to find out what happens if I do this or that. Anyways, the only way I've managed to blow the transistors is creating a short on the main board all the cables plug into or the printhead itself. The main board usually happens with ink leakage if you've moved the printer onto its side or whatever. The print head happens if you incorrectly clean the printheads by injecting solution with too much of a chemical that devolves the seals inside the printhead,allowing ink to leak out when in use or you've got the electrical contacts wet & didn't allow to dry before putting back into the printer.

Not I can't speak for other brands or models. But for the Epson XP range, they are transistors that are on the back of the main board & push up against the medal frame of the printer for cooling, because they get warm. If they get too hot, they burn out. And they get too hot if either A or B happen. They're really cheap to buy & anyone with half decent experience at soldering can fix. However, unless you find the cause of them burning out, they'll keep on burning out.
After six years of light use, my Pixma iP7220 won't power on after I tried to reset a B200 error.

I've tried Timroperco's fix several times, but it didn't work. I removed the ink cartridges and the printhead, but still no go. As many have mentioned before, the power module shows a standby voltage of 8V and 11V. Without a valid control signal to pin 1 of the power module (white wire) the power module won't output 24V and 32V.

After some careful disassembly, I now have access to the main board, But haven't had any luck trying to find a service manual for the main board. I'm going to poke around some more, but without a schematic this might be a lost cause.


Posts: 1,746   +293
For a very long time we had a basic Canon printer and when it died it was replaced with an iP7220 which displayed multiple problems within guarantee period. We couldn’t return it to a Canon service centre because that was going to be very expensive and the seller wouldn’t help. It went to the plastic landfill collection. We replaced the Canon with a far more expensive Epson XP-55 which has lasted a couple of years. If you can get 6 years out of a printer that’s pretty good. They are made to sell so cheaply that quality suffers. Money is made out of selling cartridges which ideally should be refillable but rarely are.
I managed to verify that the power module is OK: I applied an external 3V signal to pin 1 of the module and the voltages ramped up to 24V and 32V as designed. Unfortunately, that doesn't help any of the devices on the main board that need power. Once again, not having a schematic for the main board makes it nearly impossible to troubleshoot it.

Since the main board and/or the print head could be the problem, replacing them wouldn't be cost effective, seeing that a used main board is $35 and a new print head is $100. It's better to just use that money and buy a brand new printer.

What a drag.


Posts: 1,746   +293
That’s how it is. Any printer I buy in future will have an easy, free return policy for the first year. Printers are a product where I’d welcome legislation. They are a large source of plastic waste and manufacturers are able to reduce printers’ working lives by making them irreparable. Dedicated chips in cartridges is another annoyance for users making refilling or compatible versions difficult to manage. End of rant.
Apparently printers are a commodity: I have seen the price of the new printer I intended to buy fluctuate wildly the past few days.

Also, it seems that third-party sellers are hoarding printers and driving up the prices. Oddly, the iP7220 that I bought six years ago for $100 is now being sold for over $400. :eek: