On Sep 24, 11:25 pm, wrote:
Hey Folks,

I have an Viewsonic PF775 CRT monitor on an older computer. This is my
linux play box/secondary computer (ie, I don't want to spend a bunch
of money on). Went to fire it up and the monitor came up blank, though
the power light still comes on. I read SAM's repair FAQ athttp://www.repairfaq.org/sam/crtfaq.htmas well as this brief article
athttp://www.pcsupportadvisor.com/Troubleshooting_monitor_problems_page....
Though I'm pretty comfortable with microelectronics (when I have a
schematic), I'm out of my league trying to debug a CRT cold. Couple of
questions though.
1) I have a 2 yr old son that may have managed to find the contrast/
brightness controls in the setup menu. I imagine though that the setup
menu would still be visible even if these controls were set way out.
Can somebody confirm this for me?
2) I've done a pretty close inspection of the main PCB looking for
cold solder joints or signs of overheating. Is there any other simple
steps I could take before I send this for recycling? I'm debating
trying to probe the transistors for shorts, but would kindof be going
after the problem blind. Any suggestions where to start?

The other clues I can provide a
a) Monitor was working fine last time I used it. The PC/Videocard
works fine with other monitors.
b) There is some sounds when I turn the monitor on as it powers up. It
may be the degaussing. I can try describe these better if they seem
relevant.
c) Sometimes when I turn it off, there is a flash of blue light in the
middle of the top 3rd of the screen.

Given that a 17" LCD is only $180, I don't think it would be worth the
money to pay for a repair, but I may get a quote anyways. I love to
both learn and tinker, so if I do get some insight I may really dig
in. Certainly any opinions are appreciated

Thanks in advance for any help.
TMFS

Looks like the problem has resolved itself (at least temporarily). One
of the things I did to try pinpoint the problem was to power up the
monitor without a pc and look for the "input cable disconnected"
warning. Initially the screen was blank, but I inadverdantly left it
on overnight. Turns out it started to work of its own accord. Of
coarse without a cable the monitor never went into sleep mode, so the
monitor had warmed up to normal operating temp. I think this
definitely points to a bad solder joint at this point. I suspect the
problem will return shortly, so I'd still be happy to hear any
thoughts on where to start with this problem.

While it was operational, I answered my first question. Regardless of
the brightness/contrast, the user setup menu is always visible (at
least on this monitor).

Thanks Again,
Darcy