17" LCD hp f1703 problem

[ChadTower]

Did some googling, found out this monitor came fairly unreliable... but this seems to be a different problem than most are getting.  All I get is a white screen, well lit, evenly lit, but no response to any of the menu buttons.  Video source is confirmed good on another monitor.  I'm assuming that means the backlight is good... any other ideas?  LCDs are new to me.

[SirPeale]

Check the power supply for bloated caps.  I found an LCD recently that wouldn't power up, and all the caps on the power supply are bloated.  I'll replace them when I have enough for an order.

[grantspain]

do you get menu options,if so then its whatever i/c does the video decoding-if you don't then i would say the processor

[ChadTower]

Nope, no response to any of the front buttons other than power, which now that I have it apart, I can see is on a different PCB than the menu buttons.  The menu buttons are on one little PCB, the power button on its own.

EDIT:  just looked, the two boards are daisy chained.  That is helpful.   

[BobA]

If you have another power source give it a go.   The f1703 problems were caused by a poorly performing power brick.   It cculd also be your problem although the symtoms are different.  A bad power source can give many different problems.

[grantspain]

If you have another power source give it a go.   The f1703 problems were caused by a poorly performing power brick.   It cculd also be your problem although the symtoms are different.  A bad power source can give many different problems.

good call bob,i have had a problem similar caused by a bad psu but i did get some kind of pic now and then

[ChadTower]

I tested the PSU with no load... 12.2v coming through rated at 12v.  So at least with no load it's good.  I can hear it whine a little when it's really quiet, though.  Think it's possible that it just sucks under load?

This monitor apparently had all kinds of problems with bad solder joints on the power board.  I've reflowed and added some solder to most of the potential trouble spots with no change.  I'm going to do the same on the video board to see if that helps.

[grantspain]

the whine noise is what i had on my faulty psu,when this occurred i just got a blank lit screen,but it was very intermittent.in the end i just got a new psu from ebay for a few quid and its been great since

[ChadTower]

Noted.  I'll seek out a new power supply.


EDIT:  link to the part in the HP store.  Not available.  WTF.

[ChadTower]

Okay, I reflowed all headers on all boards, all of the inductors, a ton of random ---steaming pile of meadow muffin---... no difference.  I did order a power supply module off ebay.  If that doesn't work, I'm pretty much out of ideas.

[ChadTower]

Got the service manual... has all these specific pins and such to check, I can't find any of these components.  Dammit.

[ChadTower]

New power supply changes nothing... guess it's just dead beyond my ability.  Dammit.