Dell E177FPb - White Screen

[budm]

Re: Dell E177FPb - White Screen

And be real careful if you are going to put the old caps back in place (check for short after install each cap back in place before installing the next one), they can easily be damaged during removal and re-installation. You may want to look for fine cracks on the body of the cap also.

[vela]

Re: Dell E177FPb - White Screen

Thanks for the advice. It is really 1 ohm on the DMM set to measure resistance. Strange thing is that it starts off shorted and builds up to 1 ohm, which might suggest that a "shorted" cap is getting charged but pretty poorly. I was checking all the caps and as you said, a whole lot of them are showing as shorted, no doubt because they are all in parallel.

I'll go through these steps and report back what I find. Thanks again!

[vela]

Re: Dell E177FPb - White Screen

Quick update: Found the shorted ceramic cap (C24) some time back, but I don't have any replacements. Trying to get some so I can replace cap and the fuse on the board and try it. The wait is killing me :-(

[budm]

Re: Dell E177FPb - White Screen

Was it the last one you removed? Can you read the value of the good one ?

[retiredcaps]

Re: Dell E177FPb - White Screen

Found the shorted ceramic cap (C24) some time back, but I don't have any replacements. Trying to get some so I can replace cap and the fuse on the board and try it.

I didn't even bother to try with a ceramic. See here

https://www.badcaps.net/forum/showpo...1&postcount=23

I didn't take pictures on purpose due to my terrible solder job. 3 months of daily use and it still works.

[budm]

Re: Dell E177FPb - White Screen

22uF 25V sounds about right, juts make sure to install it with correct polarity by checking the voltage on other caps that are in parallel with this bad cap, the MLCC does not have polarity.

[retiredcaps]

Re: Dell E177FPb - White Screen

22uF 25V sounds about right, juts make sure to install it with correct polarity by checking the voltage on other caps that are in parallel with this bad cap, the MLCC does not have polarity.

This is the cap I used.

https://www.badcaps.net/store/produc...roducts_id=102

Yes, I checked with a multimeter to see which side was ground.

BTW, my guess as to uF was based on measuring other ceramic caps on the logic board of the same size with my multimeter set on capacitance measurement mode.

[vela]

Re: Dell E177FPb - White Screen

Cool idea using an electrolytic cap. Should have checked in here first before scrounging around and pulling a similarly sized ceramic cap off an old ethernet card and plugging it in because I saw that approach suggested in some other thread here when I was browsing some time back. I guess there is no telling if the substitute is rated for 25V or not. Unfortunately, I don't have a way to measure capacitance, so getting another similar one off the board is not going to help.
Still stuck on the fuse, though. Trying to decide if I should order replacements or go the TOM66 route and short it

[momaka]

Re: Dell E177FPb - White Screen

Cool idea using an electrolytic cap. Should have checked in here first before scrounging around and pulling a similarly sized ceramic cap off an old ethernet card and plugging it in because I saw that approach suggested in some other thread here when I was browsing some time back.

That was probably me. I've been using that method for a while now, both for LCD monitor T-con boards and other electronics too. Never had a problem with it. Oldest t-con repairs I have are (2 monitors: 19" Samsung SyncM. 931B and 19" HP W19b) about 2.5 years old now and as far as I know, both monitors still work fine.

SMD ceramic caps are usually rated for 32V and above, so most likely you won't have a problem.

Trying to decide if I should order replacements or go the TOM66 route and short it

Ok, but if you do and something else smokes, I ain't going to help .

Fuses are there for a reason. If you really don't want to get the exact SMD fuse replacement, then at least jurry-rig a standard fuse with some wires and hook that up to the t-con.

If there's no fuse on the t-con or it's over rated and there is a fault on the t-con, more than likely something else will blow too. I've seen that happen on a 17" Dell (the fuse was too beefy apparently) - I ended up spending another 2 hours looking for the problem. Finally found a completely burned transistor on the video/logic board. Had to do some jurry-rigging on that monitor to get it working.
Save yourself the trouble and put a fuse of some sort in there.

[retiredcaps]

Re: Dell E177FPb - White Screen

That was probably me.

Correct.

Fuses are there for a reason.

Otherwise, the cost cutters would have removed it.

[budm]

Re: Dell E177FPb - White Screen

You do not even have to remove the old blown fuse, you just lay the new one right on top and solder both ends to the old fuse.
YOU CAN GET 22UF 25V Ceramic SMD from MOUSER, for example:
http://www.mouser.com/Passive-Compon...ERAMIC&FS=True

[vela]

Re: Dell E177FPb - White Screen

Totally understand about the fuses. I am awaiting the parts and will report back when installed. The catch with this particular T-con is that the populated side of the board flips down against the back of the lcd panel. So there is not much space to insert any larger scale components and still fold down the board and reassemble. The fuse in particular is just below the connector to the other board and really leaves no wiggle room.

Parts should be here in a couple of days...

[vela]

Re: Dell E177FPb - White Screen

Folks, I am delighted to report that with the scounged up ceramic caps and a new SMD fuse (3A) on the T-CON board, the monitor is back up and running. Thanks for all your help! I think I am hooked and am actively looking for "broken" monitors to fix :-) .

[budm]

Re: Dell E177FPb - White Screen

Great job!

[momaka]

Re: Dell E177FPb - White Screen

Congrats!
Now when you find a "white screen", you know what to check . Can (and usually is) an easy fix if there's just a shorted ceramic cap. I like it even better than bad caps fixes because I have so many junk boards I can pull ceramic caps off of that I'll probably never run out.