HP 2509M Monitor - no display

[selldoor]

Re: HP 2509M Monitor - no display

Yes but does it look different when you do the swapping.

[northpoint]

Re: HP 2509M Monitor - no display

I did two tests swapping each pair like you suggested. The results are exactly the same. I get the normal "no source" error on the screen as its not hooked up to a computer but the screen flickers.

Im kinda worried that its the inverter daughter board having an issue as I had to repair it.

If I hookup to a computer and display a desktop it is nice and clear except for the left side of screen is dim and I have that flicker. - Picture attached.

[selldoor]

Re: HP 2509M Monitor - no display

may be due the size of the sub.
Whilst the leads may be too short to do a full swap can you swap one of the two pairs
and try it then swap that back and swap the other pair (hmm does that make sense?)
and record what happens.

By the way these are v high voltages and you should be switching the power off to swap the plugs.

[northpoint]

Re: HP 2509M Monitor - no display

I checked all connections for the bulbs with my donor bulb and they all act the same way. Blinking about twice a second. I also resoldered the joints on the output transformers.

Both caps near the inverter board show a steady 31.5 volts.

Any ideas feel free to post em ...

Northpoint

[northpoint]

Re: HP 2509M Monitor - no display

Here are the attached pics of the power/inverter board and the logic board on the monitor.

I will test each ccfl connection with my donor ccfl.

Thanks for the feedback,

Northpoint

[jetadm123]

Re: HP 2509M Monitor - no display

You'll get more accurate help if you can post a top down photo of the entire power supply/inverter board(s). I'm also thinking that one bulb is out. To narrow it down, prior to turning the monitor on, try disconnecting one ccfl plug at a time. This should help isolate which ccfl or inverter output is causing the problem.

[northpoint]

Re: HP 2509M Monitor - no display

Thank you selldoor for your reply. I just didnt want to damage the components in the monitor should there be some difference in bulb size for testing.

Unfortunately the leads are not long enough to swap them around. But I am going to try a smaller bulb for testing purposes. I just want to determine if the bulbs are at fault or if I still have an issue with the inverter circuit I fixed.

Im going to keep posting to this thread until I get it repaired or give up.

Its nice to get a reply as I have been just pouring over the threads here to learn as much as possible. Its always a great help to get some feedback on what I am doing from others.

Thanks again,

Northpoint

[selldoor]

Re: HP 2509M Monitor - no display

It is quite a big difference and may not produce the result needed but you may as well give it a try. if half the screen is dull it sounds like a bulb is not lighting but that would normally send it into protection-off.

If the leads are long enough perhaps move them around the sockets to see if the dark section moves.

[northpoint]

Re: HP 2509M Monitor - no display

I have a question about testing the ccfl's on this monitor. Since I want to isolate where the issue is. I have been reading up on the "testing ccfl's" thread that has been recommended but I did have one quick question if anyone can help me.

Im going to swap out the bulb connections with known good ones to see if the bulbs are bad. The ccfls in the monitor are for a 25 inch screen. The inverter looks to handle about 4 of them with individual connectors. Can I use a smaller ccfl to test them? The one I have is from a 15 inch donor monitor. Im just curious as will this make a big difference in troubleshooting?

Thanks in advance,

Northpoint

[northpoint]

Re: HP 2509M Monitor - no display

I have partial success! On my first post the drain on the 6030L mosfet was not making contact on the damaged daughterboard of the inverter. What I did was put on a jumper wire to make the connection as the board has surface damage on it (see my last post picture).

I got the ccfl tubes to light and got a picture on the screen. However, It flickers and is dark on the left side. Ive included a picture for anyone interested. Sorry about the quality of the pic but its from my cell phone.

Learning more all the time. Cant wait to get this repair done and put this monitor to use.

Northpoint

[northpoint]

I received this monitor in a no power state and the customer decided to opt for a new monitor instead. Therefore I inherited this and want to fix it. Doing some homework on the net I was able to replace the mosfet (FDB6030L) and the diode near it to get power to actually work. This is on what I assume is the inverter daughter board piggybacked on the power board. Now I am down to getting the ccfl's to light up as they don't. I do get a faint image of a desktop so from my experience with laptop displays I know its most likely a inverter problem. There is another mosfet on the board (P9006EDG) and I have checked it and seems to pass ok. Below is a picture of the board and a close up of the 6030L mosfet.

From the datasheet on the 6030L I see the drain is actually the tab (as you say on the north?). However, I had an "issue" removing the mosfet for replacement and removed some of the backing with it. You can see it in the second pic. Am I correct in assuming that the foil type backing under the green covering on the board is for the drain connection? Therefore I have to repair the connection from drain to the board surface?

I do get good readings from source to drain on both mosfets now. So, Iam assuming also that they are probably good.

Sorry if this appears a dumb question but most of my experience has been with single layer easy repairs. Would be nice if I could even find a schematic on the HP2509m monitor if anyone can point me in that direction I would appreciate it also.

Im new and here to learn, please be kind..