Dell e152fpc

[domyanite]

Hi all, so around my office we have a few of these dell e152s which are fairly old and now dying. One with 2 seconds to black and one with no power at all. I am fairly certain the caps have gone bad as you will see in the photos. On the one that will not power on, the fuse is blackened. Do I just unsolder that the same as the caps to replace?

[Rtech]

Re: Dell e152fpc

Changing the bad caps is correct,BUT fuses do not normally fail for no reason,so suspect there may be another problem !!A photo of the whole Board fom the top may also help.

[domyanite]

Re: Dell e152fpc

Ah, sorry about that, here is the whole board. So the bad caps won't kill a fuse? that is too bad. At least I still have one I can try to recap if blown fuse is bad news.

[budm]

Re: Dell e152fpc

When fuse is blown and has blackened inside, it was exposed too very high current. So you need to at least check the bridge rectifier and the MOSFET that drives the power trnasformer to see if they are shorted out or not.

[Rtech]

Re: Dell e152fpc

As advised by Budm, I have ringed the two components for you ....

[domyanite]

Re: Dell e152fpc

Huh well that does seem a bit more complicated, do i just run current though them with a multi-meter via the pins on the bottom of the board?

[Rtech]

Re: Dell e152fpc

testing the Bridge Rectifier.......http://www.youtube.com/watch?v=dqkT6hF0O3E

testing the Mosfet.........http://www.4qdtec.com/mostest.html

[domyanite]

Re: Dell e152fpc

Partly good news! I did not remember to bring my multi-meter with me, but I recapped one of the other dead screens and it appears to have been a success! I used Rubycon caps, the 16v1000uf's seemed a bit taller than the old ones but they fit just fine. Have only had it on for a short while but it has not gone black yet!

Thanks for the help so far!

[Rtech]

Re: Dell e152fpc

So far so good.......and next !!!!

[domyanite]

Re: Dell e152fpc

Ugh the next one is a different revision it appears once I got it apart. Totally different boards. This one has a much larger powerboard that was directly connected to video board through some pins. Also some new components to me.

This display would constantly cycle it's screen on and off. The caps look ok to me but I am no expert and one does seem taller than the others of same type. I figure recap it and see how it takes it?

[budm]

Re: Dell e152fpc

Check the resistance reading of that fuse PF751, it should be less than one Ohm, this fuse when it is bad, the resistance will be > 5 Ohms.
Also re-solder all the joints on the transformers' pins, transistors, etc. Check those transistors next to the grey tuning caps in the inverter section.
http://s807.photobucket.com/user/bud...tml?sort=3&o=0
http://s807.photobucket.com/user/bud...tml?sort=3&o=1
http://s807.photobucket.com/user/bud...tml?sort=3&o=8

http://s807.photobucket.com/user/bud...?sort=3&page=1

[domyanite]

Re: Dell e152fpc

Yes now that you mention it and examining the board a bit the power connector has a broken solder joint and it wiggles quite a bit, can even see the pin move around on the bottom side.

[domyanite]

Re: Dell e152fpc

Okay fixed up the solder for the power plug and so far it seems to be functioning properly. 2 for 3 repaired so far i think!