Monitor Repair Advice Needed
 

I have a PC monitor that works fine except for an intermittent that I have
traced to the connection between the pins in the neck of the tube and the
small pc board that is mounted on them.

Although I can't see the socket surfaces, the pins appear to be the problem,
with a dark coating that does not respond to the mild cleaners I have tried
so far. I am assuming that if I can clean the pins properly the problem will
disappear, however some form of surface treatment that leaves a non-reactive
conductive coating would be a better long term solution.

What options exist for treating the pins to leave them with a non-tarnishing
finish that will help ensure a reliable contact with the socket?

James Hahn wrote:

I have a PC monitor that works fine except for an intermittent that I have
traced to the connection between the pins in the neck of the tube and the
small pc board that is mounted on them.

Although I can't see the socket surfaces, the pins appear to be the problem,
with a dark coating that does not respond to the mild cleaners I have tried
so far. I am assuming that if I can clean the pins properly the problem will
disappear, however some form of surface treatment that leaves a non-reactive
conductive coating would be a better long term solution.

What options exist for treating the pins to leave them with a non-tarnishing
finish that will help ensure a reliable contact with the socket?



I'd be surprised if it was the pins, more likely is the spark gaps in
the socket acquiring dirt that makes it arc across too readily. The
spark gaps are there to protect against high voltages in a fault
condition, a sufficiently high voltage will arc across and be shorted to
earh. But if there is dirt in the spark gap the gap will be shorter and
it will arc over at a lower voltage - perhaps within the normaal
operating range of that electrode. The solution is to generously flush
the tube base socket through with alcohol, which should work.

2 warnings:

make sure it is fully dry before you put it back on

nearly all electonic components will be quite happy having a bath in
alcohol, but s few things won't be. If you are not confident of
assessing this yourself then to be safe you should remove the tube base
socket before cleaning.

Good luck

If you have the appropriate equipment and skills I'd suggest removing the
CRT socket from the pcb assembly. De-Soldering, cleaning, and Re-Soldering
required. Then do a through cleaning of the PCB, both sides, and the CRT
socket, reinstalling it after thoroughly cleaned and inspected.
"Luke Siemaszko" wrote in message
...


James Hahn wrote:

I have a PC monitor that works fine except for an intermittent that I
have traced to the connection between the pins in the neck of the tube
and the small pc board that is mounted on them.

Although I can't see the socket surfaces, the pins appear to be the
problem, with a dark coating that does not respond to the mild cleaners I
have tried so far. I am assuming that if I can clean the pins properly
the problem will disappear, however some form of surface treatment that
leaves a non-reactive conductive coating would be a better long term
solution.

What options exist for treating the pins to leave them with a
non-tarnishing finish that will help ensure a reliable contact with the
socket?

I'd be surprised if it was the pins, more likely is the spark gaps in the
socket acquiring dirt that makes it arc across too readily. The spark
gaps are there to protect against high voltages in a fault condition, a
sufficiently high voltage will arc across and be shorted to earh. But if
there is dirt in the spark gap the gap will be shorter and it will arc
over at a lower voltage - perhaps within the normaal operating range of
that electrode. The solution is to generously flush the tube base socket
through with alcohol, which should work.

2 warnings:

make sure it is fully dry before you put it back on

nearly all electonic components will be quite happy having a bath in
alcohol, but s few things won't be. If you are not confident of assessing
this yourself then to be safe you should remove the tube base socket
before cleaning.

Good luck

If you're VERY careful, you can get a better connection by lightly scraping
the pins with a dull knife. This helps to remove some of the oxide.

Also, carefully spread the pins outward just a skosh with long-nosed pliers.
This gives the pins a better grip in the socket.

BTW -- Are you sure that the solder connections on the CRT socket are OK?
That's often a weak spot. Resoldering those joints will often help.

Thanks. I have replaced the whole socket, so I'm confident about the solder
joints (and the spark gaps, which I don't believe were ever an issue).
Gently scraping the pins removes a covering which sure looks like it would
prevent the connection, but the problem re-appears in about two weeks. I am
only scraping the exterior face of the pins, where I can see exactly what
I'm doing, which is why I thought a different cleaning technique that could
safely get around the whole pin might be better. I'll try the gentle
bending trick, as that will increase pressure on the surface I can scrape,
but the pins appear to be made from a very brittle metal.

The latest fix is to use a plastic tie to put some upward pressure on the
board, and currently that seems to be working!
--
"Matt J. McCullar" wrote in message
m...
If you're VERY careful, you can get a better connection by lightly
scraping
the pins with a dull knife. This helps to remove some of the oxide.

Also, carefully spread the pins outward just a skosh with long-nosed
pliers.
This gives the pins a better grip in the socket.

BTW -- Are you sure that the solder connections on the CRT socket are OK?
That's often a weak spot. Resoldering those joints will often help.

Caig make excellent products for cleaning all electronic terminations.
They have a web site and even sell at RadioShack now.