Chimei CMV221D black screen ?

[jh20]

Re: Chimei CMV221D black screen ?

do we have a solution to the op's problem? i have the same monitor with the exact same psu board and exactly the same problem as well.

i have replaced all the capacitors on the board and it's still not fixed. the strangest thing is if you switch it off then on, it comes back for a few more seconds before going dark again. so it is definately not a hard failure issue.

have done what plainbill suggested and got exactly the same result as the op's. no image at all when off, and the voltage at the fuse are 19.1 when on and 21.6 when off. so what does that mean? login board issue?

i have also checked the output voltages from the psu. the 5v is 4.95v and 13.8v is 13.81v. the 5v is a touch low but don't think that's an issue? the voltages stayed the same whether the screen is on or off.

any more suggestions or tests to do before i binned it?

[jh20]

Re: Chimei CMV221D black screen ?

That looks the same Power suppy/Inverter as this Thread
https://www.badcaps.net/forum/showthread.php?t=8265
Might help with Common faults

forgot to read this thread first before posting

so looks like it's the tubes problem. not to worry, i'll just bin it. it's too old and the colour quality is bad anyway.......

thanks for reading.

[jh20]

Re: Chimei CMV221D black screen ?

Common failure mode.
I've done that one more with laptops in which it's usually a bad inverter or tubes.

.

just a follow up as i decided to get to the bottom of this.

pcbonez was right! i pulled the screen apart and the top ccfl has a broken tube (pair of 2). replaced the pair with one from a lg 22" monitor that has a broken lcd and the problem seems to be fixed. monitor has been on for the last 1 hr and it's still going

unless it falls over later, otherwise consider this as fixed

[Amraks]

Re: Chimei CMV221D black screen ?

I picked one of these up for 10 dollars today and its not turning on.

Can't wait to investigate more. Things have been quite lately in this field.
apart from stereo I am fixing.