Normal on cheap monitors but this one is tough to repair. Usually capacitors and glue turning conductive.

Second, this is usually the flyback transformer not stiff enough. Yours is working correctly and no faults. Have to accept that since replacing flyback will not help here. I see this happen on cheap replacement flyback transformers made whole raster to swell and shrink with brightness changes.

Turn down brightness a little helps some.

Is yours model high end or mid end? Sony keeps good stuff reserved to high end stuff this why one have to pay lot to get good quality.

Cheers,

Service manual.

https://servlib.com/sony/monitor/cpd-15sx1.html

Cheers,

This is caused by anode voltage fluctuation, this monitor does not have HV regulation, only compensation, so this is perfectly normal for it and unfixable pretty much. Reduce brightness and it will get slightly better.

Thanks for the replies. I honestly always thought Sony Trinitron was the cats pajamas, guess I didn't realize this was normal to a degree as I don't recall ever having similar issues with CRT's back in the 90's even with my super cheap CTX and Cybervision branded monitors.

This monitor was purchased off ebay several years ago, so I didn't know how it preformed normally when it was new, just thought something must have been wrong with it cause to me it is quite distracting. Will try to lower the brightness and see if I can live with it. Thanks again for the answers. My first thought was there had to have been a fault.

pentiumspeed wrote on 2022-09-23, 14:47:

Service manual.

https://servlib.com/sony/monitor/cpd-15sx1.html

Cheers,

Thanks Pentiumspeed. I will try to navigate this service manual and glance over the pages here and try to find any reference to test points for proper voltage measurement. I don't know if this is high end, my guess is it isn't. The monitor shows a manufacture date of 4th quarter 1996.

Turned brightness down and still have huge distortion. I just can't believe this would be normal behavior or people would be okay with this picture. I can't get this distortion any better than this.

This much is definitely not normal so there is some actual problem somewhere. I can only suspect some capacitor(s), since all else appears to work. EW correction part is where the answer most likely is.

lowlytech wrote on 2022-09-24, 00:42:

Turned brightness down and still have huge distortion. I just can't believe this would be normal behavior or people would be okay with this picture. I can't get this distortion any better than this.

20220923_193945.jpg

This second post photo looks much worse then before. Did you do anything?

As already said... this wasn't out of the factory geometry. Something went wrong along the way... it's around 25 years old...

No, nothing changed. Infact the pots all still have the glue holding their factory set values. Other than running in 800x600, that is the only difference (beleive this monitor can go to 1024x768). Connected it back up to my p233 machine and geometery is better in dosshell or edit, but still distractingly messed up.

There is a shape adjustment on the front panel, but it is like a bad keystone setting on a projector where you can only get one side straight, and the oppisite side is always way out of whack.

Otherwise this montior is one of those DAS models where some settings are set via software

In DOS resolutions it can be adjusted to acceptable geometry. Guess this monitor should be for DOS only .

It's a shame that the service manual (at least the low-quality scan above, which is the best I've found online) doesn't have a schematic or any explanation of what the adjustment pots are for. I have one of these monitors with different problems (and more minor, except for convergence around the edges).

I wouldn't expect DAS to fix that problem, but once again, there is a lack of service information for this monitor (or Sony products in general unless you can still buy the manual from Sony directly or a used print copy somewhere). My wild guess (especially since I haven't actually fixed many CRT monitors) would be power supply regulation or something in the horizontal deflection section (like the east-west correction mentioned above - according to the service manual above, it's using a TDA4950 for that, and it's what the front panel shape control adjusts).

Width and pincushion, trapezoidal corrections comes from 3 signals. High voltage current sensing (through the flyback transformer), horizontal timing and vertical timing is used to create a *corrected* width via a PWM pulses via a inductor tied into part of the horizontal deflection circuit. This comes from two ways, one analog part for general adjust (pots), and digital especially fine control, (the settings that you adjust with buttons and DAS).

Cheers,