"Trevor Wilson" writes:

"David Harmon" wrote in message
...
I recently got an ancient monochrome video monitor from a friend.

This thing probably hasn't been powered on for fifteen or twenty years.
I'm thinking I will put it on a variac and turn it up slowly from zero
over several hours, to maybe let electrolytic caps reform, and avoid
anything else that might object to getting suddenly whacked with a full
120 volts. Is that a good idea? Is there anything in a video monitor,
like maybe the high voltage supply, that will object to running on
reduced voltage for a few hours at first?

**Very risky. The thing may use a SMPS. It will certainly use an LOPT driven
by a high frequency oscillator, which may or may not start, when gradually
ramped up. You may end up causing more damage. Or not. It's a crap shoot
IMO.

Agreed. Just apply normal power. At least you'll know pretty quickly
if something's going to blow up.

It may be OK if it wasn't used over that time and was stored in a cool place.

To be doubly sure, you could check the ESR of electrolytic caps in the
power supply and deflection, and/or simply replace the main filter caps.

How important is it to get the monitor going?

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.