Feint moving lines on 5400 when adjusting brightness / contrast

[jmb2011]

I just picked up a week ago a Power Mac 5400 AIO system. I’ve been playing around with it some, and it works perfectly except for one thing I’ve noticed. When adjusting brightness and contrast, very feint slow scrolling lines will appear. It only happens when adjusting the monitor controls, and sometimes at startup. I think maybe the brightness of the monitor may be a little dull, but I’m not sure since I’ve never seen an AIO like this before.

what do you think could be the cause? Aging capacitors on the analog board?

 

[Byrd]

If using a metal tool to adjust pots on the CRT, interference can occur - try using a chopped up wooden skewer. Sounds like the brightness is a little too high and contrast low; all in all though it sounds normal and not suggestive of failure. CRTs also take a good 5-20 mins to warm up

 

[LaPorta]

Just as a small aside: faint means small or almost imperceptible, feint means to deceive in an attack.