Haas Monitor "vibration"

Hi,

2002 SL-10 (This is the older style, monochrome monitor)

With the machine powered up, running in cycle, or at idle, there is a small "pulsing" that is going on in the monitor. It looks like the entire screen is trying to shink from the center by about 1/32". It doesn't effect operation, everything is still clear, but it's enough to make you think that you've had a beer on the job.

This has been a recurring problem that seems to solve itself every few months. The way i get a temporary fix is to unplug the monitor and plug it back in. Problem goes away for a little while, but comes back eventually.

We're not located in a region prone to earthquakes either.

Thank you, Jeff.

Is the shrink in one direction only? Horizontal or vertical? Could be any number of things, but sounds like a capacitor is giving up somewhere. Most likely electrolytic since a power off changes things for a while.

If one direction, in a horizontal or vertical sync circuit. If all over...power supply. Would need to be isolated to the monitor as video signal could be suffering a power issue too (meaning the problem is not the monitor itself).

Shink is in both directions. Like if the screen was pliable and one was poking at the middle.

Guess the bad part is that this is not a simple DIY project. CRTs typically use high voltage / high frequency power. All of which is dangerous in inexperineced hands. I would still lean towards a power issue in the monitor itself and an electrolytic capacitor that essentially is "repairing" itself when the power is removed but relocates it's defect after a time altering the current and causing the change on the screen. Could be found by monitoring power voltage with a meter when the issue is recreated...but really is headed towards professional repair or replacement (neither of which are cheap and intermittent issues can be hard to diagnose and repair in a repair shop). Sent to a manufacturer, they usually repair by throwing parts at the issue until it is changed or just replace as a lower cost option.

I've seen a couple of monitors have problems with the connectors developing slight corrosion or miscontact after a few years. Its worth a shot to disconnect the power and let it sit for a while to let the caps all discharge and then take the case off and disconnect and reconnect all the connectors in the monitor. When they are disconnect look for any signs of corrosion and clean them off if you find it.

Paul T.

There are also chemical spray cleaners and contact enhancer products that can help connection issues and maybe a little easier than mechanical cleaning. Oxidation messes with everything over time. Generally bad connections don't change with power up/down but a poor contact can make some strange events.

Still, take great care around CRTs there are some nasty currents contained there with enough voltage to let that current jump respectable distances.

Going on 3 hours now.. think the problem is licked.

Took a look at votage going to it... ~ 129V. Took a look at the line voltage coming into the machine...changed since the last time I looked, adjusted the taps on the transformer. Voltage going into the CRT is now 118V and no more flicker. We'll see...

Thank you for your thoughts..