Help with Cannon iP4850 Printer

[SmartestSmarty]

Hello all,

My Cannon iP4850 Printer just stopped working. It won't turn on now.

Can you give me some advice please on how to fix it?

Any help will be appreciated.

Thanks in advance.

[selldoor]

Re: Help with Cannon iP4850 Printer

Test all fuses is a good place to start.

[SmartestSmarty]

Re: Help with Cannon iP4850 Printer

Thanks for your reply,

When you say all fuses, I didn't know there was more than one?

I've tried a different power cable.

Heres a pic of the power board, how to I test it?

[selldoor]

Re: Help with Cannon iP4850 Printer

Thanks for your reply,

When you say all fuses, I didn't know there was more than one?

Perhaps there isnt - and your picture doesnt help much either alway best to have them in focus.
What does it say on the two small rectangular boxes - top right

[SmartestSmarty]

Re: Help with Cannon iP4850 Printer

Sorry about that, I've changed the original image, hopefully it's a bit clearer now?

The one on the right says: INSFT 2.5 A 250V
One on the left says: INSFT 2 A 250V

[trebo]

Re: Help with Cannon iP4850 Printer

and there is a third to test at bottom of picture

[SmartestSmarty]

Re: Help with Cannon iP4850 Printer

The third says INSFT 2.5 A 250V

I have a multimeter, can you explain how to test them please

I also have a soldering iron, so I can replace anything if necessary

[selldoor]

Re: Help with Cannon iP4850 Printer

Turn the board over and find the solder joints that relate to the fuse.
Set your meter on ohms 200 and put the probes one on each joint.
NO power to the board

We also like pictures posted using manage attachments jpgs less the 3mb
so they are available for future enquirers ( Will dissappear otherwise)
I have added yours here

[SmartestSmarty]

Re: Help with Cannon iP4850 Printer

OK, i'll keep that in mind for the future.

The reading is quite high and then settles at about 1.0 on all of them. Is that normal?

[selldoor]

Re: Help with Cannon iP4850 Printer

Is that 1 ohm or is it "1" on the left of your meter scale meaning OL (open link)

The result should be the same as you get if you touch the probes together
What you have may be the result when the probes are apart?

[SmartestSmarty]

Re: Help with Cannon iP4850 Printer

When the probes are apart it starts with 1 on the very left.

When I touch the probes together I get a reading of 00.8/00.9 on the right.

When testing the solder points I get 01.0 on the right.

[SmartestSmarty]

Re: Help with Cannon iP4850 Printer

Is this normal?

[selldoor]

Re: Help with Cannon iP4850 Printer

Well that seems pretty much bad news - not an easy fix- are all 3 the same?

Next test will verify a couple of things. But may be considered dangerous if you are new to electronics. Ideally you should have someone in the house and use a RCD.

Locate the solder joints relating to that BIG CAP on the bottom of the board.

Set up the board (bottom up) on a non conductive surface -and wedge so it isnt going to move about when you plug it in.
Then switch it on.

Set your meter on vDC600 and put a probe on each joint of the big cap
DO NOT TOUCH ANYTHING ELSE . MAINS VOLTAGE !!

[SmartestSmarty]

Re: Help with Cannon iP4850 Printer

Well that seems pretty much bad news - not an easy fix- are all 3 the same?

Next test will verify a couple of things. But may be considered dangerous if you are new to electronics. Ideally you should have someone in the house and use a RCD.

Locate the solder joints relating to that BIG CAP on the bottom of the board.

Set up the board (bottom up) on a non conductive surface -and wedge so it isnt going to move about when you plug it in.
Then switch it on.

Set your meter on vDC600 and put a probe on each joint of the big cap
DO NOT TOUCH ANYTHING ELSE . MAINS VOLTAGE !!

Thanks,

Yes they are all the same.

Any idea what to wedge it with?

Also here's a pic of my meter, I can't find that setting?

[selldoor]

Re: Help with Cannon iP4850 Printer

When the probes are apart it starts with 1 on the very left.

When I touch the probes together I get a reading of 00.8/00.9 on the right.

When testing the solder points I get 01.0 on the right.

Yes - normal - in fact better than some.

When you hold the probes together is measures the resistance of the wire and probe tips - 0.8 in your case.
When you test the fuse the resistance of the fuse is actually 0.1 - 0.2 so the total is 1.0. This is something to remember - if you are testing low resistance resistors subtracting the "probe lead resistance" can make quite a difference.

[SmartestSmarty]

Re: Help with Cannon iP4850 Printer

I retested them, and they all say 00.8 the same as when I touch the probes together.

[selldoor]

Re: Help with Cannon iP4850 Printer

Any idea what to wedge it with? Come on !!! If you are using a socket with a switch
set it all up and put a heavy weight on the cable should hold the cable and board down- then switch it on at the socket.
You can do the same if its going live when you plug in - just dont yank the cable.

Somepeople try and do this sort of test with their elbows on the table. and touch the board as lightly as possible. ( Usually working with heavier boards)

[SmartestSmarty]

Re: Help with Cannon iP4850 Printer

What is the wedge for? Incase you accidentally move it and it touches you? Or when I turn it on is it likely to start moving by itself?

Also, when I touch the probes on the live cap soldering joints, it's not going to melt the handles is it and give me a great big shock?

Also, I can't find the setting you mentioned on my meter?

[selldoor]

Re: Help with Cannon iP4850 Printer

Use V flatline 3 dots 1000


It wont move by itself but that board is very light compared to the cable so it could move
then your probes could damage something on the board.
If it sparks you will react and could end up touching the board
If it helps wear rubber gloves and wellies (yes that is a joke)

Probe handles wont melt

[SmartestSmarty]

Re: Help with Cannon iP4850 Printer

Thanks, have I got the probes in the right terminals? Com and VΩmA