Sony Widescreen CRT Picture Problem

[user181]

I have a Sony KD-34XBR970 and have been noticing horizontal streaking & blurriness issues in the picture during initial startup. It is across the bottom portion of the screen, but predominantly in the lower-left corner. It eventually settles out after 30-45 seconds and then everything looks OK.

Here is a video of what I am trying to describe:
https://youtu.be/zc7R13Fte44

What are the probable causes of these issues, and are there any possible repairs?


Also, this is the same set I have written about in a separate thread which has had the blinking LED startup failure problem occasionally. It occurs about 3-4 times a year, and if I unplug the set momentarily, it has then turned on successfully.

I am aware of the issue with the MCZ3001DB chips and have spares (genuine) on hand, but have not replaced them yet. Could the screen issues above be related, or are they an altogether separate thing?


Thank you!

[zeno]

Can you hit it & get it to come & go ?
Watch any Sonys for cold joints especially around the hoz drive & out, vert IC
& the small 3 legged regulator IC's ( 12V, 9V, 5V etc.) .
Around shields also.
Try different inputs also. That may be a clue.
Electrolytics also a strong candidate. Most likely a surface mount.
A can of freeze mist can be a real friend on this one.

73 Zeno
LFOD !

[JohnCT]

Originally Posted by user181

I am aware of the issue with the MCZ3001DB chips and have spares (genuine) on hand, but have not replaced them yet. Could the screen issues above be related, or are they an altogether separate thing?


Thank you!

No, the MCZ chips are historically a binary go-no go failure mode. I've changed a couple of hundred of those and never saw them cause any performance issue.

You can try preheating the chassis with a hair dryer before the first start. If the picture starts and runs normally, probably a crappy electro.

John