Strange Monitor Problem

[mike9h29]

Hello.

I have a benq 19" TFT Monitor (FP91G+) with a strange fault.

If I connect it to the mains and switch it on, it will switch on and work fine (even for 11 hours!). But, if I connect it to the mains and leave it off for about 15 minuts it will not turn on.

I`ve also seen it popping up the OSD menu randomly sometimes.

I`ve replaced all the capacitors (including the Big one!) but its still doing the same thing.

Any ideas please?

Thanks

Mario

[alexanna]

Re: Strange Monitor Problem

I am going to make a guess.
When the monitor has been plugged in and not turned on there is still some heat being generated.
A pretty common fault of not being able to turn on and off with the front pannel switch on a monitor is failure of a voltage regulator on the logic board ,I have had voltage regulators when they were initially tested show good but as they warm up the voltage drops off.
Al.

[mike9h29]

Re: Strange Monitor Problem

I am going to make a guess.
When the monitor has been plugged in and not turned on there is still some heat being generated.
A pretty common fault of not being able to turn on and off with the front pannel switch on a monitor is failure of a voltage regulator on the logic board ,I have had voltage regulators when they were initially tested show good but as they warm up the voltage drops off.
Al.

Hi,

Thanks for the reply.

How can I check the voltage regulator please? or its better if I just replace it?

Also, how come it works fine when in on mode and will go bad just in off mode please?

Thanks

Mario

[alexanna]

Re: Strange Monitor Problem

Hi,

Thanks for the reply.

How can I check the voltage regulator please? or its better if I just replace it?

Also, how come it works fine when in on mode and will go bad just in off mode please?

Thanks

Mario

I really don't know if that is your problem or not. You're just going to need to start checking some voltages to see if any are different when the monitor is working and when it's not.
That was just my suggestion on something to check first, there other things that can cause problems.
If you use the advanced search feature retiredcaps has written a lot about “LDO voltage regulators, or voltage regulators” and how to check them.
A good detailed photo of the logic board would really help a lot.
Al.

[dobber]

Re: Strange Monitor Problem

I have a simular problem sometimes with my gateway 24", but it is that it will not shut off after being on for very long times, like it just becomes unresponsive. I just unplug and call it good, not worth the change of tearing it down if it still works.

[jetadm123]

Re: Strange Monitor Problem

Hello.

I have a benq 19" TFT Monitor (FP91G+) with a strange fault.

If I connect it to the mains and switch it on, it will switch on and work fine (even for 11 hours!). But, if I connect it to the mains and leave it off for about 15 minuts it will not turn on.

I`ve also seen it popping up the OSD menu randomly sometimes.

I`ve replaced all the capacitors (including the Big one!) but its still doing the same thing.

Any ideas please?

Thanks

Mario

Please post a good focused photo of your logic board. Also, you said that if you leave it off for 15min, it won't turn on. So, how do you get it to turn on?