HP 2159m - No signal issue

[Lledargo]

I recently aquired a HP 2159m monitor. The monitor will turn on for a short period of time after having a video source (Can be HDMI, VGA, or DVI) and AC power plugged in, it will display a menu that claims it cannot detect a signal from any of the video sources, then the display goes into stand-by.

So far, after reading a few threads about this monitor and general trouble shooting:
- I tested the fuse on the power supply to have no resistance.
- The large cap on the powersupply has ~160V across it.
- The +5V leads from the powersupply to the mainboard measured 5.28V.
- The voltage regulators I could find tested as follows:

U202
⊃||8J4
17-18L
Pin 1 - 0.000V
Pin 2 - 1.781V
Pin 3 - 3.500V

U201
⊃||8BU
17-33L
Pin 1 - 0.000V
Pin 2 - 3.28V
Pin 3 - 5.006V

I could not find datasheets for the VRs, as they seem to have unusual model numbers, I can take pictures of each regulator though my magnifying glass if anyone would like to see. I am of the impression that because a nice constant 5.3V is coming off the powersupply, that the issue must be with the mainboard.

Other than that the only information I can think to give is the monitors product number:
FV585A

and regulatory model number:
HSTND-2571-T

All help is greatly appreicated. If I forgot anything please let me know, I will try my best to get you any desired information.

[Lledargo]

Re: HP 2159m - No signal issue

A little thing I over looked, for some reason there is a missing capacitor (C854) on the top right of the power supply board in my top veiw, bottom right in the bottom view attached. Looking at the traces, it went between the Gnd and VADJ (voltage adjust?) pins on the connector. Any ideas what it is for?

Also, I am about 99% sure I am the only person to have opened this display before, I did not notice a cap floating around in the case, and I did not notice any caps break off while I've been working.

Also, as the bottom veiw shows, there is solder on the holes where a the cap should be.

[Lledargo]

Re: HP 2159m - No signal issue

Decided I might as well attach an up-close picture of the traces near the conncector and missing capacitor.

[budm]

Re: HP 2159m - No signal issue

There was nothing installed at that location from the factory, you can tell from the look of the pad, the holes are cover by solder from wave soldering.

The regulator voltage readings are correct.