Printer power supply mysteriously dead. Twice.

Thread Starter

Spright

Joined Jan 5, 2018
5
Dear electronics people,

Hope you won't be annoyed by this post. I'm completely ignorant in electronics (but also curious and motivated to learn). This post only marginally fits here, perhaps, so apologies upfront.

In short: how can it be that I opened my inkjet printer to see if something is jammed inside, and after I reassembled it it wouldn't power on, and when I in frustration bought the same day another printer, almost identical model, and had to open that one too, it too wouldn't power on afterwards?

Mind you, I'm not asking you guys to fix my printer or something like that. I'm interested in the pure electronic science of this predicament. Also, perhaps there's something important I need to notice while opening my next printer...

Both printers (Canon PIXMA) were second hand, several years old. No power problems before opening. No blows or abuse during opening. No indication of any burnt fuses, no sparks or anything. Tried giving them a rest, pluging with other cords, all around the house: nothing.

I suppose the culprit in such cases is the power supply. Can't tell you anything about mine, I don't have a multimeter.

So: does this make any sort of electronic sense? Surely Canon doesn't install a self-destruct mechanism in their printers to ward off hobby technicians. I assure you I didn't touch any component other than the paper-feed rollers.

What do you think?
 

dendad

Joined Feb 20, 2016
3,625
It sounds like you either broke something or forgot to plug it back in.
If there are ribbon connectors you have unplugged, did you put them back together the correct way up?
That is an easy trap to fall into.
 

Thread Starter

Spright

Joined Jan 5, 2018
5
It sounds like you either broke something or forgot to plug it back in.
If there are ribbon connectors you have unplugged, did you put them back together the correct way up?
No, really, I didn't touch, not to mention unplug, anything.

What about ESD? Could this have nuked both my PSs? I never use any precaution, and I delve inside my computer all the time, without any detrimental effects. Even if there was ESD this time, can the PSs be so sensitive that they immediately die? And anyway, the PS components are hidden in a plastic case, which I've touched profusely even BEFORE opening the printer, so why is it dead only AFTER I opened it?

Hmmm!
 

Thread Starter

Spright

Joined Jan 5, 2018
5
Was the printer showing a 'paper jam' error message?
If so, did you follow these instructions?
If there was no error message, why did you suspect a paper jam?
Yes, paper-jam error message, followed the instructions, but there was no paper inside. In such case every YouTube guide recommends opening the printer to see if dust, hair, or other particles are stuck in the rollers. Nobody ever reports such immediate death...
 

xox

Joined Sep 8, 2017
496
Yes, paper-jam error message, followed the instructions, but there was no paper inside. In such case every YouTube guide recommends opening the printer to see if dust, hair, or other particles are stuck in the rollers. Nobody ever reports such immediate death...
Seems to be a pretty common problem with these printers. It'd be interesting to know what's actually causing the failures...
 

MrChips

Joined Oct 2, 2009
22,113
Take a look at this, copied from a printer repair forum:
----------------------------------------------------------------------

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 ..
 

atferrari

Joined Jan 6, 2004
4,122
Dear electronics people,

Hope you won't be annoyed by this post. I'm completely ignorant in electronics (but also curious and motivated to learn). This post only marginally fits here, perhaps, so apologies upfront.

In short: how can it be that I opened my inkjet printer to see if something is jammed inside, and after I reassembled it it wouldn't power on, and when I in frustration bought the same day another printer, almost identical model, and had to open that one too, it too wouldn't power on afterwards?

Mind you, I'm not asking you guys to fix my printer or something like that. I'm interested in the pure electronic science of this predicament. Also, perhaps there's something important I need to notice while opening my next printer...

Both printers (Canon PIXMA) were second hand, several years old. No power problems before opening. No blows or abuse during opening. No indication of any burnt fuses, no sparks or anything. Tried giving them a rest, pluging with other cords, all around the house: nothing.

I suppose the culprit in such cases is the power supply. Can't tell you anything about mine, I don't have a multimeter.

So: does this make any sort of electronic sense? Surely Canon doesn't install a self-destruct mechanism in their printers to ward off hobby technicians. I assure you I didn't touch any component other than the paper-feed rollers.

What do you think?
Had I lived your experience, something I would NOT do is trying to consider both cases together but separately. Otherwise you risk trying to force your conclusions to explain a maybe-non-existant common cause. You could end chasing a ghost that is not.

Divide and conquer.
 

Thread Starter

Spright

Joined Jan 5, 2018
5
Had I lived your experience, something I would NOT do is trying to consider both cases together but separately. Otherwise you risk trying to force your conclusions to explain a maybe-non-existant common cause. You could end chasing a ghost that is not.

Divide and conquer.
Well, I wouldn't object a separate answer for each one of the cases...

But wouldn't you say that the nearly identical conditions in both cases, combined with the apparent propensity, as reported above, of many a Canon printer to die in a similar manner, renders the 'ghost' very real?
 

atferrari

Joined Jan 6, 2004
4,122
Well, I wouldn't object a separate answer for each one of the cases...

But wouldn't you say that the nearly identical conditions in both cases, combined with the apparent propensity, as reported above, of many a Canon printer to die in a similar manner, renders the 'ghost' very real?
Coincidence? Looks like.

In my job, when investigating incidents, I leave the conclusions for the very last. I work for different type of professionals that for a variety of reasons, ask me to give an opinion when I did not even completed the investigation. I always refuse to give anything that could look like an opinion until I have considered all the info at hand. I do try to not waste my time.
 
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