Convergence off on top half of the screen only ?

[Nipedley]

Hi guys

Just a quick one really. I picked up a couple of CRT TVs recently, both the same model. One won't turn on and the diagnostic LED built in gives a 'dead tube' error, the other fires up no problem however the convergence is off. Frustratingly, it's only off on the top 40% of the screen. The vertical and horizontal convergence is off. I'm a little confused here because from what admittedly limited knowledge I have of convergence adjustment, it should be one static adjustment and one dynamic adjustment for the edges right? I can't think of what would cause the top half to be out and the bottom half to be totally fine

Just wondering if it's worth pursuing (they also smell like damp shed which is not the nicest) or whether I should dump it and look for another. They're getting pretty hard to find nowadays though :-(

[mourix]

Can you give the TV model and take some pics of the issue? Some modern CRT's got complicated convergence systems while others do not, so I can't really guess from a written description.

[Nipedley]

Thanks for the reply, it's a Sony 21X5U and the service manual is available here: https://www.manualslib.com/manual/788516/Sony-Kv-21c5b.html?page=17#manual

I had a look at the convergence adjustments in the manual but they only seem to be for whole-screen adjustment. I don't have a pic but if you imagine splitting the screen 40% top 60% bottom, immediately after the split the horizontal and vertical convergence is off, horizontal is worse and is maybe .8cm off. The bottom 60% of the screen is totally fine