MPC All in One 414 424
So far every one that I have worked on has had a bad CCFL tube.
The common symptom is that it comes on for a short time and blanks out but the external video works fine on an external monitor.
I test them by removing the LCD panel
and mounting it externally like this.
Lay the computer face down with the lcd close by
Then patch the two cables into the computer
Using an assembly from another monitor I can clip into the
harness and attach to a CCFL that I can test it with.
If the CCFL is new a quick test is ok.
If the CCFL is used then burn it in and look for any
discoloration since they tend to go orange before failing.
Here you can see that this appears to be a good used tube
I will let this run for a few hours just to be sure.
It is a good idea to test the screen before you disassemble
the panel so you don't waste time installing CCFL's in a bad LCD
You can also see here I have an external tube assembly
patched in to keep the screen working while I examine it.
This is a broken LCD and very obvious but also has a bad
CCFL tube which required the external one in order to test.
Here you can see a panel with a good LCD screen but a bad CCFL
I patched in an external CCFL assembly in order to keep the unit
running long enough to test.
Because this one has two CCFL connecters you can determine which
CCFL is bad before you take it apart.
This is only a dos screen so a windows complete display is better.
email if you have questions