Re: HP ZR2740w almost dead

Back at this again, I noticed that the PSU board makes a rattle when I shake it, and it seems to originate from C812, a blue ceramic cap I suppose. It's right next to back light connector, seems to be between the ground potentials of hi/lo voltages. Could this be the culprit? I guess none of these parts should rattle..

Re: HP ZR2740w almost dead

I replaced only the caps on the main board, not on the PSU board, since I can get it to wake up using the pull up resistor method. I replaced all electrolytic caps on it.

Re: HP ZR2740w almost dead

Now I have replaced all the main board electrolytic capacitors, made no difference. Hmmm... What to try next.

Re: HP ZR2740w almost dead

I just measured this some more, seems the problem is in the main board as I was able to get the back light on using pull ups to PS-ON and On/Off. So it seems the main isn't giving enough voltage to wake up the power supply board. Are there any suggestions on what might be wrong with it? I'm thinking of caps because the problem began just like a dying power supply problem starts, randomly not starting up and eventually not at all.

Re: HP ZR2740w almost dead

Hello all!
I have this very same monitor on hand, started blacking out erratically at work, got replaced and brought it home. Soon didn't work at all. Blue light for a few seconds, then amber. Didn't get any voltage readings measuring the LED-connector. On the P803 the 5V is live, but 12V pins don't give anything. Thinking of PSU board having an issue with that. Do the LED drivers have their own transformer(s) or are they related to this 12V output? Any suggestions on this? All the caps look fine, but I haven't tested them in any way.

Re: New Members - please post your introductions here

Hiyall! Stumbled upon here while searching for info on fixing an HP monitor. Had to sign in to see the pics and, we'll, here I am. I am a mechanical engineer, but had some electronics courses as well, mostly manufacturing related, though. Always been interested in electronics, never really dove into it other than making and fixing the simpler stuff.
Located in Finland, working as a designing consultant, mostly designing chemical pipelines and steel structures.

-TY-