lj_robins ha escrito:

Mike wrote:
I follow what the rest are saying. a scope would be very handy in this
situation. you could easily see overloading in the output waveform if the
yoke is shorted.

but one thing I noticed too is the raster is awful bright.


"Mike" wrote in message
...
check your caps on the horizontal side of the deflection yoke.


I had a viewsonic P775 do that stupid ****, but it would also take out the
HOT after a bit. turned out to be a couple of those notorious blue HV
caps.



"lj_robins" wrote in message
. ..
Hi,

I'm working on a monitor for a friend of mine, she said that it smelled
like burning plastic for three days before it went bad.

The monitor:
"Proview model: 786N"
"Product no: PS720F-1s"
"Product series: DZ-777NS"

When you first turn it in the relays click like they are supposed to,
after a moment or two the little "Check signal" window pops up, but it is
scrunched on the left side and spread way apart on the right side. The
screen looks normal otherwise.

At least this is what I thought until I opened the case the turned the
brightness up, the vertical appears to be fine, but the horizontal stops
about three inches from both sides of the screen.

My first thought in this is that the horizontal section is not getting
enough voltage, if I turn the brightness all the way up the picture
shrinks inward even more (although it does get brighter). I posted a
picture online if you want to look at this:
http://home.comcast.net/~lj_robins/badmonitor/

One other thing is that the buttons on the front will not active the
geometric adjustment menus but they will bring it out of "sleep" mode.

Nothing appears to be burnt of fried on either side of the circuit board,
I'm not sure where to start with this thing, any suggestions?


-Landon



Hi Mike,

The raster is very bright because I turned the SCREEN adjuster knob next
to the flyback transformer up so I could see where the edges of the scan
lines were actually at. At it's normal setting the screen is black with
the little "check signal" window in the middle.

After it appears on the screen 4 or 5 times the monitor goes into sleep
mode, the high voltage shuts down and then you can hear the static
crackle as all the dust looses its static charge. If you turn the
monitor off/on or hit one of the adjuster buttons it comes right back on.

Right now it is not hooked up to a PC, so all it will do is the "Check
signal".


-Landon

check any caps (usually rated 1kv or more) near where the horizontal
coils from the yoke attach to the mainboard. something is wrong in the
path to the horizontal yoke, (which may even have shorted turns but
repalce the caps first).

-B.