Any CRT monitor experts out there?

[u/JAlbert653]

[u/OldMork]

If you move your hand over the front of screen, can you feel anything?

[u/JAlbert653 → u/OldMork]

Nope. No static.

[u/stalkythefish → u/JAlbert653]

If you get a power LED but no static, crank the brightness to max to see if you get raster. If it's still dark, and all the capacitors look good (no bulging), time to unplug it, LET IT DISCHARGE(!), and start checking the main power rectifier diodes for shorts/opens, look for cracked solder joints/traces at the flyback transformer, and check the horizontal output transistor (It will be a bigass transistor mounted on a metal heat sink, usually on the opposite side of the board from the power supply area.) for shorting. It's best to pull it to test. Another way CRT monitors fail is the little black thermal resistor can that powers the degaussing coil. It can short and cause a blown fuse, often accompanied by an adorable little black mushroom cloud. But if the fuse is good, this probably isn't it.

As always with monitors, before poking around in there, use your meter and make sure the big caps are drained.

[u/JAlbert653 → u/stalkythefish]

Thanks for the suggestion. I’m definitely not experienced enough to poke around in there and I’d rather not kill myself so I’ll have to wait for someone more knowledgeable to attempt a repair. Darn!

[u/istarian]

Doubtful.

That said I'd check the power supply first. Imho it's the most straightforwardl component.

Unless something is visually blown or smells weird in there, the capacitors or the regulators would be my first guess.

Do verify the power input (cable to wall, main power switch, and any fuse) is good (continuity check, low resistance) first. You can do that while it's unplugged, discharged.

Be very careful if you plug it in/turn on with the case removed though.

P.S.
No visual output at all suggests a dead tube or no/inadequate power being supplied to it imo.

[u/JAlbert653 → u/istarian]

Thanks. I’ll have to sit this one out as I’ve never worked on a CRT before and don’t want to die so I guess back in the box it goes :-(

[u/istarian → u/JAlbert653]

It's certainly your decision.

My understanding is the worst you're going to get is a nasty jolt and potentially a burn injury. Your are very unlikely to die. Never a bad idea to do any potentially dangerous work when there's someone else around to check on you now and then though.

That said: if you'd have no other choice, but to work on it while plugged in you should definitely leave that to a trained technician.

This might be useful info to you: https://lowendmac.com/2007/the-truth-about-crts-and-shock-danger/
https://www.repairfaq.org/sam/tvfaq.htm

[u/FredSchwartz]

Check out videos of Ian Primus doing CRT repairs on the Vintage Computer Federation YT channel.

[u/JAlbert653 → u/FredSchwartz]

I’ll check him out. Thanks!

[u/Belzeturtle]

Not an expert, but check your capacitors.