cannon printer powersupply problem.

[rievax_60]

Re: cannon printer powersupply problem.

Maybe the output voltages are supposed to be low while in standby mode. Take a closer look at transistor Q5. Is it tied in with the resistor divider on the input pin on the 431 voltage reference IC? It's between the opto and Q5.
This is an example of how the 431 IC is applied. http://i.cmpnet.com/powermanagementd...67-Figure1.jpg

[gordesky1]

Re: cannon printer powersupply problem.

Ok i heated it up real hot than tried it and i still get nothing.. Than i tested the voltage at the plug were the printer wire plugs in the white plug. It has 4 blue wires and 1 5 wire . And when i have the probes on the last blue wire and white wire i get around 11.79v than i keep testing each wire when i have the probes on the same white wire and the middle blue wire i get 8.79v,

On the back of the cover of the of the psu that was on it, The voltages says 32v 0.75a 24v 0.5a. shouldn't i be getting 32v and 24v somewhere on that plug?

heres the pic of the plastic cover its not my pic but the same thing.


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[gordesky1]

Re: cannon printer powersupply problem.

Will heat it up and see what that does.

[stj]

Re: cannon printer powersupply problem.

if it worked while the psu was warm and now it's cold it wont run - think small caps.

heat the bastard with a hair dryer and then test it while it's hot!

[rievax_60]

Re: cannon printer powersupply problem.

Those output voltage do seem a little unusual. Without knowing for certain, they have to be accepted for now.
There are methods for being more certain. Checking for ripple with an oscilloscope or just replacing the output capacitors. Also confirming that the regulation loop is working properly by tracing out the circuitry involving the opto and measure the voltage on the TL431 refrence IC.
If the power button is a tactile press button switch, they can fail to contact after not being used for a long time.

[gordesky1]

Re: cannon printer powersupply problem.

A friend had the same sort of problem with his Canon MFP after a power outage. He had simply forgotten that It needed to be turned on. It had a well hidden touch switch.
Not all power outages have surges associated with them.

Wish it was just a hidden switch on this one lol The power switch is right on the lid were all the other buttons and lcd..

Tired even holding it down which usely resets it which did nothing, it was also left unplugged for a month which should of cleared everything.


Now if this was a cheap no good printer i toss it. But its a pretty good one which had alot of life left before one side of the house went out..

[rievax_60]

Re: cannon printer powersupply problem.

A friend had the same sort of problem with his Canon MFP after a power outage. He had simply forgotten that It needed to be turned on. It had a well hidden touch switch.
Not all power outages have surges associated with them.

[gordesky1]

Re: cannon printer powersupply problem.

Ok just tested with dcv and here's what i get.

Big cap 450v 176.5v

The 2 end caps 11.72v and the other is 8.92 one is a 50v cap and the other is 35v

And the very small caps not sure if they the start up ones or not i got 13.16v and 13.89 on the other they both 100v caps.

So i was indeed testing them wrong.. lol Does those voltage sound right?

Im wondering if its in the printer itself...

[budm]

Re: cannon printer powersupply problem.

You should used DCV mode since you are testing DC Volatage on the main filter cap. same thing when check the DC on the output side of the power supply.

[gordesky1]

Re: cannon printer powersupply problem.

Post 10 "Than i tested the big 450v one i ony get 1.100v at that.. " So the dcv between the two legs of the main filter cap only has 1.1Vdc when the board is plugged into the AC outlet?
It should have 165~170VDC as long as it is plugged into the AC outlet.

Yep that's what it showed, what it looks like it seems like the psu is not fully powering on.

Tho i was looking on my meter and saw 10megohm input dcv above the acv.
should i be using that instead of acv? Didn't even pay attention to that option..

[budm]

Re: cannon printer powersupply problem.

Post 10 "Than i tested the big 450v one i ony get 1.100v at that.. " So the dcv between the two legs of the main filter cap only has 1.1Vdc when the board is plugged into the AC outlet?
It should have 165~170VDC as long as it is plugged into the AC outlet.

[stj]

Re: cannon printer powersupply problem.

it wont cost more than a $ to replace the caps - just in case.
something decent like panasonic NHG series.

[gordesky1]

Re: cannon printer powersupply problem.

the volts arent from the caps, they are going into the caps.

btw, those are 1uf 100v
the H is actually a u with a low tail - it means "micro"
i'm not sure they are startup caps if they are only 1uf though.

Yea i was having a hard time trying to figure it out if its a h or u lol

Just wish i knew what is wrong.. was wondering if it damage the printer boards it self. tho i would think it would've did damage to the psu first.

would try to get a new psu for it sense the printer is worth fixing for under 50$ and i also got refillable ink carts in it. But don't want to get one and find out it still don't power on and its inside...

[stj]

Re: cannon printer powersupply problem.

the volts arent from the caps, they are going into the caps.

btw, those are 1uf 100v
the H is actually a u with a low tail - it means "micro"
i'm not sure they are startup caps if they are only 1uf though.

[gordesky1]

Re: cannon printer powersupply problem.

foto of those caps please.
btw, you cant test them wih a multimeter.

best i can get to it close.. nothing wants to focus today lol


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Hmm i thought mutimeters can test them? So they cant test the volts?

[stj]

Re: cannon printer powersupply problem.

foto of those caps please.
btw, you cant test them wih a multimeter.

[gordesky1]

Re: cannon printer powersupply problem.

I just looked at this video to see how you test bridge rectifier

https://www.youtube.com/watch?v=11JPy4t36oo


and they came back as 595-620ohms. so i guess nothing is wrong with that?

[gordesky1]

Re: cannon printer powersupply problem.

ok i tested the volts from those 2 small ones when plugged in and i get 0.35v than the other one shows 0.06v both are 100v 1Hf caps.. than i tested the Ohms when off 1.018 for one and the other is 1.024.

Does 1hf sound right? i usely see mf and uf.

[stj]

Re: cannon printer powersupply problem.

yes, the 2 small electrolytics on the mains side.

[gordesky1]

Re: cannon printer powersupply problem.

ah.
so it was plugged in continuously,
the house tripped out,
then it wont restart.

how old is it? i'm thinking the small startup caps.

Yep it was always on mostly and the house tripped and the printer never turn back on.

Its about 3 years old. well going on it.

Is the start up caps the ones closest by the mains plug?