2021-11-11 Chimei LCD monitor Delta power supply fixed

From Wikistix

tl;dr: It was the CapXon electrolytic capacitors! All the CapXon capacitors!

Chimei Delta Power Supply

I dabble as a hobbyist in electronics, but I still feel proud when I manage to repair some piece of gear with a soldering iron in my hands. This time the backlight on my aging Chimei CMV 221D LCD monitor from March 2007 refused to come on. It had been playing up for a while, only coming on about 25% of the time I turned the monitor on, so I'd gotten into the habit of leaving it on all the time, and disabling the sleep mode. Unfortunately, I had to turn it off for a night, and after that, it refused to come on. So, I pulled it apart and uncovered the power supply, and immediately located a problem. Six problems, in fact. Three are pretty obvious in the photo, with visible leaks, especially the large main input 120µF 400v filter cap, and the two towards the centre-right (220µF 25v and 1000µF 25v). Two more show noticeable bulges (both 220µF 25v), and the remaining one, the 1000µF 25v one lying down towards the top-right also has a bulge not visible in the photo.

All the black CapXon caps, and only the CapXon caps, were either bulging or leaking. 20 minutes later after a quick walk to Jaycar, I had replacement caps. De-soldered the CapXon caps, soldered in the replacements, and bingo, one working monitor, which I'm using right now to create this page!

Misinformation found herein copyright Paul Ripke (aka “stix”) stixpjr@gmail.com.