PF775 blank screen

[[email protected]]

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 at
http://www.repairfaq.org/sam/crtfaq.htm as well as this brief article
at http://www.pcsupportadvisor.com/Troubleshooting_monitor_problems_page2.htm.
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 are:
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

 

[hr(bob) [email protected]]

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 are:
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

Just to make sure it is the monitor, and not the PC to which it is
attached, try a second monitor before assuming it is the monitor that
is at fault.

Two-year-olds can do some wonderful things, maybe he/she can undo
whatever they did <G>.

H. R. (Bob) Hofmann

 

[[email protected]]

Just to make sure it is the monitor, and not the PC to which it is
attached, try a second monitor before assuming it is the monitor that
is at fault.

Two-year-olds can do some wonderful things, maybe he/she can undo
whatever they did <G>.

H. R. (Bob) Hofmann

Sorry, should have noted that I have already tried a different monitor
(which worked fine). I also hooked this monitor up to a known good PC
just to be conclusively sure that it is the monitor.

Darcy

 

[[email protected]]

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 are:
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