"David Farber" wrote in message
...
This 17" Dell monitor, model number CN-0M1609-4633-3AG-2DTL, will power
on
when AC is first applied. In the middle of the screen appears, "Dell
Genesis
Display Perfection." Then it disappears after a second. When you press
the
power button with no input signal, the Dell self test feature check
illuminates in the bottom left corner of the display. You can see the
red,
green, blue, and white bars within the self test box. Then, it starts to
scroll diagonally up to the right for about a second and then the
display
turns off. The power light remains on. If you hook it up to a PC, you do
not
get any display. The boards are in good condition and I reflowed the
solder
over many of the components with no improvement. Any ideas what might be
going on here?

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA





wrote in message
...
Hi David, i believe it should be ok with the trannies out, it just means
that one channel will not be driven.

Would be interested to know if you still have the same symptom (on for
2-3
secs and then off) with the trannies out.

I think what is happening is that the PWM chip is detecting overcurrent
and
shutting down. I found that with BD911 transistors in in place of the
2sc5707 i am still getting the same problem but i cant find any more s/c
devices. As i understand it , with these monitors this is a real common
problem, even if you manage to get the thing working its likely to break
down again, with the same devices s/c a day/week/or even months later. It
seems its always the same channel (the top lamp) that goes but no-one
really
knows why. I also understand that the transformers are suspect and go s/c
or
arc internally. Dry solder joints are also a major problem as are poor
quality electrolytic caps.

I am coming to the conclusion that this monitor suffers from a major
design
fault from new, they seem to just make it out of warranty and then fail
:-)

Apparently many service shops now refuse to handle them, they are a
warranty
claim waiting to happen.

I am going to continue working on it though as i hate to give up on things
like this, its my own monitor so cost isnt an issue but for repair shops
it
well cold be.

Anyway, let me know what you find with the voltages, should be
interesting.

Regards

Graham

Hi Graham,

I checked the voltage at pin 9 of the TL1451A chip and have come up with the
same results that you found in your monitor. The voltage swings from 14 to
18 volts after shutdown.
--
David Farber
David Farber's Service Center
L.A., CA