Cannot turn on artisan 700 ? no power ?

[max-damage]

Hi
Yesterday my artisan 700 has stop working suddenly, just powered off in the middle of printing proces.
I cannot turn it on, no power at all, tried to hold power button, nothing .
So I disassembled it, my suspect was the power supply has gone bad. When I hold "on" button, Im hearing strange "clicking" from power supply.
Now, I dont no if it is power supply or main board.
Here is picture of power supply



I cannot find any fuse ? But if there is a fuse, there wouldnt be any clicking sound from it ? Right ?
I would like to find out what are voltage values at the out of power supply, so I can measure it and find out if it is a bad supply ?

thanks

 

[max-damage]

Ok, there is three fuses on board
I have check them with multimeter, all three are fine

 

[PeterBJ]

The clicking sound could indicate that the power supply starts, but immediately shuts down due to an over current. Holding the power button repeats the cycle, causing the clicking sound.

In Canon printers a short circuit in the print head will prevent the printer from turning on. If you remove the the defective print head, the printer will turn on, of course with an error message.

The cause of the over current could be both in the power supply and in the printer. If the fault is to be found in the power supply I would suspect the two low voltage electrolytic capacitors in the lower right corner. You could try changing them.

I think the large electrolytic capacitor at top is the mains reservoir capacitor. If you live in a 230V area it will charge to around 325VDC during use, and it is not isolated from the mains, so beware!

If the fault is in the printer, I don't know how to test it or what to do. Epson print heads are unlike Canon print heads not user exchangeable.

I'm not an electronics pro, but an experienced amateur. My knowledge is mostly with analog circuits, I have only basic knowledge about switch mode power supplies, and my printer knowledge is mostly about Canon printers. Maybe others know more about these power supplies plus Epson printers?

 

[max-damage]

Hi
Thanks for replay.
There are no signs of bad capacitor, i have inspected them all
http://en.wikipedia.org/wiki/Capacitor_plague

Large capacitor is 400V, i have mesaured voltage on in while the power supply is connected to AC, multimeter is showing me about 320V, but when the power supply is connected also to printer, it is showing me about 400V (AC).

But, the weird thing for me is, I cannot manage to find out from where the "clicking" sound is comming out, I know it is from power supply, but I cannot determine witch element ?

If I could manage to find out what are voltages rates at the end of power supply, I could easily know if it is damaged power supply.

 

[PeterBJ]

My guess is the clicking sound is caused by the switch transformer located in the upper right corner. The large current pulses could cause the windings and the core to contract due to magnetic forces.

Often a defective capacitor will bulge, but maybe it can be defective without showing signs of physical damage?

Maybe the service manual will be helpful? Link here: http://elektrotanya.com/epson_artisan_700_800_px800fw_tx800fw_px700fw_tx700fwl.pdf/download.html . Before downloading files from electrotanya, see this instruction: http://www.nifty-stuff.com/forum/viewtopic.php?pid=61324#p61324

Edit: As you have already replaced the electrolytic capacitors, sadly I think the error is possibly in the printer Thanks for the Wikipedia link. I think it is a good article.

 

[max-damage]

Hi
I have been reading manual yesterday, id doesnt say anything about power supply, only where is located
I dont think the capacitors are bad, maybe ?, i have mesaure voltages rates on all three of them, voltages are fine but I dont know hot to measure capacitor

I forgot to tell, when first time epson power off itself, i could managed to get him turned on, but only for about 30 seconds, than again it shuts down,again I turn it on, but only last for about 5 sec. From that, I cannot managed to turn it on at all ?

 

[max-damage]

I didnt replace capacitors, I will try to do that next week, also, what are possibilities that switch transformer is out ? is it normal to have clicking sound from it when the switch transformer is good ?

many thanks

 

[PeterBJ]

I have also experienced the clicking sound with a power supply problem. I think the transformer is OK and the clicking is caused by large current pulses.

I had an old Dell monitor fail, it would only turn on for a few seconds. Searching Google I found repair suggestions one recommending to replace switching transistors and another recommending replacing capacitors. I unsoldered the transistors and checked them, they were OK. After putting the transistors back, I then replaced a handful of capacitors suggested in the other link, and the monitor was OK again. The tricky part is that the capacitors didn't appear damaged, I guess they lost capacity due to old age. Here are the links to the monitor repair, maybe you find something useful?: http://syscon.wordpress.com/2007/07/13/dell-dell-e172fpb-lcd-backlight-repair/ and: http://www.ccl-la.com/blog/index.php/dell-e172fpc-e173fpc-repair/

 

[max-damage]

Thanks for links. definitely I will try to replace capacitors... here in Croatia it is hard to find capacitors in local shop so I will order some from ebay.
I will post results here. thx