Main > Monitor/Video Forum
CRT (Makvision) image is a large bluish blob. Dead, or repairable?
grantspain:
so if it was a chassis i was working on the first thing i would do is desolder the ptc and the blue gun, give you a good idea of whats going on
Baldbull:
Finally got around to looking at this thing again..
Unsurprisingly, it did not fix itself :)
It goes without saying I'm a novice when it comes to CRTs. I'm sure I'm in over my head. Have to start somewhere right?
I have a basic knowledge of electronics and have found the schematics -- https://na.suzohapp.com/pdf/service_pdfs/M2929D4G-TS.pdf, but am at a loss as to where I should begin.
Am I doomed?
jennifer:
Without actually running some tests it would only be a guess...But if I was to make a guess...Since you are getting RGB, I would be suspect of the retrace (flyback) circuit on the chassis...Thats a high voltage potentially faulty circuit friend, It may be somewhat unpredictable, be careful and approach with caution ⚠️.
jennifer:
A good place to start would be (Imo) would be probe the anode with a good quality high voltage Kv probe, and see what you are actually getting at the tube....Yokes and purity generally don't change over the life of the tube, but if you moved that stuff for some reason, the convergence is most likely off and that would also cause those problems,
Baldbull:
--- Quote from: jennifer on January 25, 2021, 04:35:35 pm ---A good place to start would be (Imo) would be probe the anode with a good quality high voltage Kv probe, and see what you are actually getting at the tube....Yokes and purity generally don't change over the life of the tube, but if you moved that stuff for some reason, the convergence is most likely off and that would also cause those problems,
--- End quote ---
Problem just started out of thin air... cabinet was not moved.