Hi All,
I have an ACER model #7278C computer monitor. When it is powered up,
the screen appears to only scan the lower half of the screen. There is
a bright line accross the middle section of the screen. below that
line, it looks OK, the top half is black. The video appears to be cut
off, meaning that it is not simply squashed into half of screen. It
"Looks" like the top half of the video is collapsed into that bright
line, while the bottom half is normal.

I'm an electronics guy by trade, but It's been quite a while since
I've repaired TV's or monitors, so I could use some guidance here from
you pros. I'm hoping that I can avoid sending this to the landfill.

Any ideas where to start looking?

Thanks very much for any ideas.

Best regards,
-AL

wrote in message
oups.com...
Hi All,
I have an ACER model #7278C computer monitor. When it is powered up,
the screen appears to only scan the lower half of the screen. There is
a bright line accross the middle section of the screen. below that
line, it looks OK, the top half is black. The video appears to be cut
off, meaning that it is not simply squashed into half of screen. It
"Looks" like the top half of the video is collapsed into that bright
line, while the bottom half is normal.

I'm an electronics guy by trade, but It's been quite a while since
I've repaired TV's or monitors, so I could use some guidance here from
you pros. I'm hoping that I can avoid sending this to the landfill.

Any ideas where to start looking?

Thanks very much for any ideas.

Best regards,
-AL


This symptom is often caused by the flyback boost electrolytic or the
associated diode, also check if the V-O/P chip runs from split PSU rails -
one of them could be absent.

wrote in message
oups.com...
Hi All,
I have an ACER model #7278C computer monitor. When it is powered up,
the screen appears to only scan the lower half of the screen. There is
a bright line accross the middle section of the screen. below that
line, it looks OK, the top half is black. The video appears to be cut
off, meaning that it is not simply squashed into half of screen. It
"Looks" like the top half of the video is collapsed into that bright
line, while the bottom half is normal.

I'm an electronics guy by trade, but It's been quite a while since
I've repaired TV's or monitors, so I could use some guidance here from
you pros. I'm hoping that I can avoid sending this to the landfill.

Any ideas where to start looking?


Probably a failed vertical output IC, and/or associated electrolytic
capacitors.

Dave

I've had more than one of these have faulty transistors in the vertical
signal processing, before the output IC, leaky from collector to emitter,(I
think, or was it emitter to base?!?!), any who, these were NTE 123ap, very
common with these multi-res monitors. Hope this helps.
Cheers, Steve.