CRT - Sony CPD-E250 Suddenly Dim

[zalves]

I got this Sony CPD-E250, 17" CRT the other day. When I got home is was working fine, set at 80% brightness, 75% contrast. The next day was ok, but suddenly it got a lot dimmer, had to set brightness to 100% contrast is also at 100%, just for almost normal use. After a few hours of use it got even dimmer, now even with brightness and contrast at max, it's too dark. Colors seem very vivid still. Below are 2 examples of what I see, in warcraft I can't see the green grass in a fully dark room. I tinker with eletronics a bit and have opened a couple of CRTs before, but I'm not an expert by any means. Any suggestions for this sudden drop?

[jd213]

Maybe a low G2 voltage issue due to aging caps or other components, if there's a pot for it you might be able to adjust it for a temp fix. Don't see the E250 service manual for free but the E200 one is on the CRT Database, might be good enough.

[zalves]

Maybe a low G2 voltage issue due to aging caps or other components, if there's a pot for it you might be able to adjust it for a temp fix. Don't see the E250 service manual for free but the E200 one is on the CRT Database, might be good enough.

Couldn't find the service manual for free either, I guess I'll have to buy it. Think it's time to open it up and have a look at it inside to see if there is anything off.

[KPackratt2k]

For what it's worth, I've managed to find the service manual for the HMD-A240R (basically a CPD-E240 with a different case design) from the CRT Database page for that model, it might be a close enough match to your monitor.

https://archive.org/download/trinitron_ ... da240r.pdf

[tongshadow]

Does the OSD get dim too?

[Kiki2024]

you should see firstly if the osd gets dimmer or not. If not very probably is the signal part the issue.
Then, you must think it is 20-25 years old stuff and crt monitors used to get problematic in those areas. Is this a model with windas mandatory?

[zalves]

you should see firstly if the osd gets dimmer or not. If not very probably is the signal part the issue.
Then, you must think it is 20-25 years old stuff and crt monitors used to get problematic in those areas. Is this a model with windas mandatory?

The OSD is also dimmer. I've also connected to two different sources to confirm. I'm not sure if it's windas mandatory, but it does have the serial connector for it on the side. I should have taken better pictures. but this how the FBT is looking, also didn't see any apparent damaged caps. FBT had reference NX4405/VQL4.

[Kiki2024]

you should see firstly if the osd gets dimmer or not. If not very probably is the signal part the issue.
Then, you must think it is 20-25 years old stuff and crt monitors used to get problematic in those areas. Is this a model with windas mandatory?

The OSD is also dimmer. I've also connected to two different sources to confirm. I'm not sure if it's windas mandatory, but it does have the serial connector for it on the side. I should have taken better pictures. but this how the FBT is looking, also didn't see any apparent damaged caps. FBT had reference NX4405/VQL4.

ok. If osd is dimmer too it is a monitor itself problem not the signal related part (which is better). Could bedifferent causes even the crt tube itself going to die.
Very probably could be eat flyback too yes but must be verified. Those flyback are impossible to find so we must work on it. Windas on these models is useless, they are still with old method with trimmer. just bump up the g2 (screen trimmer) and see what is happening, brightness should go up

[zalves]

I think I might have solved it, I have adjusted the screen pot on the FBT, just around 1 or 2 degrees clockwise, it became normal again. let's lee if it holds with usage...

Apreciate all the replies, good to have such community.

[Kiki2024]

yes, keep it that way, surely no problem nomore