T240 Monitor Backlighting Issue

[budm]

Re: T240 Monitor Backlighting Issue

So the backlights did come on for seconds and then black out? Then it may be bad lamps, bad MOSFET (the SMD with 5 legs on the bottom and big tab on top), bad inverter power supply section, bad BL_ON signal, ETC.
Can we see staright shot pictures of the top and bottom side of this Power supply-inverter board. It may be time to make two test lamps.

[lizzrd]

Re: T240 Monitor Backlighting Issue

I talked to the lady friend that gave this to me. She said it turned on for a minute then went blank. Seems longer than the OP and others. ?
I see no visual wire or connection /tubes burns...

[stj]

Re: T240 Monitor Backlighting Issue

the large yellow cap near the heatsink looks like the top has started to dome slightly.

[budm]

Re: T240 Monitor Backlighting Issue

I talked to the lady friend that gave this to me. She said it turned on for a minute then went blank. Seems longer than the OP and others. ?
I see no visual wire or connection /tubes burns...

So you took the panel apart to get the lamp assemblies? If I were you I would use two test lamps to find out if you have board problem or lamps problem.

[lizzrd]

Re: T240 Monitor Backlighting Issue

thanks again for the replies, i did not take the panel apart farther. I saw a reference about the test lamps ,clf bulbs ?, so i'll search that out.
i will keep those two yellow caps in mind...

[selldoor]

Re: T240 Monitor Backlighting Issue

We really need to know if when you switch it on NOW does the screen flash at all?

The link to the cfl is in budms signature 2 posts above.

Oh ho! you have managed to hide a fuse from us. Did you check the White one F102 in the middle of the board- Hiding behind the heatsink is a green torpedo fuse f 301 to test as well.

Test fuses - No power to board meter on ohms 200 one probe to each side of fuse
should be same as holding the probes together.
Next test after that is to turn on the power and test the voltage at each side of the green fuse with the black probe on chassis ground.

[lizzrd]

Re: T240 Monitor Backlighting Issue

thanks sell door, to be honest i am just getting back to this project...

[flying welshman]

Re: T240 Monitor Backlighting Issue

Sorry for the thread necro, but i just wanted to thank everyone in this thread. I had the same problem as the op and this thread told me everything i needed to know to open up the monitor, test components, find that my problem was a faulty transformer and replace it. So now instead of however much it would have cost to get it repaired or having to buy a new monitor, i am only down £20 and am the proud owner of a new multimeter, new soldering iron and a fully working monitor.

[aster1x]

Re: T240 Monitor Backlighting Issue

My problem is that the monitor produces a naty smell as if the board has overheated and burned. My transformer has visible plastic distortion due to heat. The monitor is working perfectly but the back panel at the are of the power supply is warmer than the other side and it smells badly.

I believe the transfmer has arched and overheated. Shou I replace it?

So far I have realized that the power supply boards IP-58155A have the TM-0918 inverter transformer and their power supply cord plugs perpendicular to the board.

At the begining of the thread there is another power supply board which I can not tell the part number, its power supply cord plugs in parallel to the board and they use the TM-10160 inverter transformer.

What is the difference between the two inverter transformers TM-0918 and TM-10160 ?

Both part numbers are available on ebay.
Are they compatible to each other?