Dell E177FPv - No video

[MEB]

Hello. I realize this monitor is not worth the trouble, but I can't help it.
I got 2 of these. After recapping both PS boards, 1 works fine, the other has no video.

Using the working one as the donor, the second monitor works fine upon substituting the video board from the working monitor. So I pretty much know (assume) it is the video board. This is only an $8 board on ebay, but I'm looking to learn something if possible. The caps on the board appear fine and are not Elites or Cap-Xons, and attempting to check ESR with old "blue" and my DVM shows also good and not shorted. I am not able to locate a fuse. I have enclosed pictures of the video board in question. I am not sure where to begin.

[budm]

Re: Dell E177FPv - No video

What dcV do you get on all 3 pins of U6, U7, Q5?

[MEB]

Re: Dell E177FPv - No video

Thanks budm. It is always a pleasure.

Attached are the voltages. I wasn't sure how else to list them without confusion. Am looking forward to your reply, but it is Illinois time and am off to a tractor pull at the fair, so see you tomorrow!

[budm]

Re: Dell E177FPv - No video

The Voltages are OK.

[MEB]

Re: Dell E177FPv - No video

Back to business. Ready for more troubleshooting.

[MEB]

Re: Dell E177FPv - No video

budm, is there any more I can do?

[budm]

Re: Dell E177FPv - No video

You will probably need to use the scope to see if there is any signals on the LVDS cables to the LCD panel, or the XTAL is active.
BTW, does it work if you try cooling or heating the board?

[MEB]

Re: Dell E177FPv - No video

OK, went with the second suggestion first as I am not real efficient with a scope. I turned on the power, no video, heated board with heat gun as much as I thought I could get away with and no video after a few minutes. Powered it on/off a few times, still no video. Removed video board, wrapped in paper towel and put it inside a plastic bag and put in the freezer for an hour. Took it out and connected it to the rest, waited a minute or two for the moisture to disappear some and powered it up. Video came right on! But, now it won't fail even trying to heat the board with the heat gun again. I guess I will just leave it running and see what happens? Thanks for your help thus far.

[budm]

Re: Dell E177FPv - No video

You can use canned air duster upside down for cooling, I wonder if it has bad EEPROM.

[MEB]

Re: Dell E177FPv - No video

Thanks for the air duster info. I was kind of concerned about the frosty freezer board! It has been quite a few hours now and the darn thing is still working. I cycled power a few times and it keeps coming back with video. I will let it run overnight I guess and will try to read up on the eeprom as I don't know anything about those. It might be U1 on the board as 24LC02BT datasheet says it is an eeprom?

[MEB]

Re: Dell E177FPv - No video

Well, the monitor ran fine overnight. Guess I will assemble it and see how long it lasts. Thanks for your help.