[noname23]

G'Day


I have a Sony KV-32HS420 HDTV that started playing up - white was lost and only pure red/blue was visible and a little green. Affects all inputs, cable, antenna etc. However the onscreen menu works fine (all the colours are normal).


Any ideas? Here is a photo with my laptop connected to a forum. All the black should be white.


http: // futchfactor.com/upload/IMG_4561_450.jpg


(please remove the space after http

thanks in advance

f

 

[jdre]

I lost all the brightness information on my old Sony XBR, it was an open connection in the video signal path (delay line solder cracked). (It is from 1985, had an excuse!) I looked at the schematic for my 32HS510 and also the 34XBR960, similar enough to your set. Many possibilities in the B board. IC2801 on B or BY board. I would check for loose plugs to B board first. Also, really try all inputs you can (Component HDMI) first, list results.

 

[noname23]

heya, thanks for replying. i've checked all the inputs - HDMI through S-video on the front. all have the same issue. the strange thing is that the onscreen menu has no issues and displays fine.

 

[raouliii]



Quote:
Originally Posted by noname23 /forum/post/15460263


heya, thanks for replying. i've checked all the inputs - HDMI through S-video on the front. all have the same issue. the strange thing is that the onscreen menu has no issues and displays fine.

That's not very strange when you consider that the menu is likely generated in the MID which is VERY late in the video chain. I would consider that a positive since the crt and its drive circuits are likely not the culprit.


When you say you checked all the inputs, have you checked all of the actual inputs (video1, 2, 3, etc.) or each type of input (composite, component, etc)? Have you checked the monitor out to see if video is correct on the output? Have you tried unplugging the set for a few hours? Have you performed any service menu activities? Have you moved the set recently?


I am a little confused about your problem, so I'll ramble. Since white is a combination of all three colors, the loss of only green would result in a blue/red (magenta). Red and blue are obviously available but your statement and the jpg appears to indicate that there is a complete lack of video where white should be. What color should the red and blue portions of the jpg, be?

 

[noname23]

Hi, thanks for your reply R.

Quote:
Originally Posted by raouliii /forum/post/15461271


When you say you checked all the inputs, have you checked all of the actual inputs (video1, 2, 3, etc.) or each type of input (composite, component, etc)? Have you checked the monitor out to see if video is correct on the output? Have you tried unplugging the set for a few hours?

yes, tested all. ie, antenna in, cable in, RCA (yellow/white/red cable) in, HDMI 1,2,3 and S-Video/RCA on the front of the TV in. All show predominantly red/blue picture with faded green. Perhaps that is key - the red and blue are intense which the green is a dreary olive colour. Picture is very dark, almost black as though no white is coming through.


Green is visible in the JPG as a small dot , about 2 inches in, 2 inches down, upper left corner;


http: // futchfactor.com/upload/IMG_4561_450.jpg

Quote:
Originally Posted by raouliii /forum/post/15461271


Have you performed any service menu activities? Have you moved the set recently?

No to the first - not sure if I can enter Service mode since I have a universal remote (original remote broke). No to the second - the TV never moved (too heavy) and the problem started and got worse over a 4 week period until permanent.

Quote:
Originally Posted by raouliii /forum/post/15461271


I am a little confused about your problem, so I'll ramble. Since white is a combination of all three colors, the loss of only green would result in a blue/red (magenta). Red and blue are obviously available but your statement and the jpg appears to indicate that there is a complete lack of video where white should be. What color should the red and blue portions of the jpg, be?

In the JPG, the bright red represents a reddish-burgundy and the bright blue represents a normal mid-blue, similar to what you might see on the title bar of Windows XP.


If there is a test-image online you'd like me to use, I can hook my laptop up to the TV again and take a photo of it.


Cheers

F

 

[raouliii]



Quote:
Originally Posted by noname23 /forum/post/15466243


...yes, tested all. ie, antenna in, cable in, RCA (yellow/white/red cable) in, HDMI 1,2,3 and S-Video/RCA on the front of the TV in. All show predominantly red/blue picture with faded green. Perhaps that is key - the red and blue are intense which the green is a dreary olive colour. Picture is very dark, almost black as though no white is coming through........

What about Video 5 and 6, component video, both 480i and 1080i? Were different resolutions used with HDMI, 480i and 1080i? I ask because the video appears to be routed through the set differently depending on the resolution. What about the monitor out?

 

[jdre]

I'd est monitor out to another TV if possible, to test TV set non HD tuner and composite video path Video 1-4. The green is always dull compared with red and blue when no brightness information present (my experience with a few successful TV set repairs). 5,6 are Component, worth a try. You do have an internal problem there. B board area.

 

[noname23]

hello all,


thank you for the helpful replies. i have tested everything as advised and here are the results:


- ant, video 1-4, component 5-6, HDMI 7, s-video 2 all have the problem (all red/blue, no luminosity). inputs 5-7 all tested at 480,480p,720p,1080i signals.


- monitor out works. i ran cable TV into the bad TV, connected a good TV via monitor out, and the picture came through on the good TV.


i have pulled the back off and i will look for the circuits/dials/chips mentioned here.


one question - which one is the B board looking at it from the back?


thanks again

f

 

[jdre]

You will need the KV34HS420 service manual (includes 30,32,34,36HS420), available for one download here, see page 13 BY board: Sony 34HS420

 

[noname23]

hello jdre,


i've got the manual and have 'read' through it. there are lots of codes and abbreviations so i'm not sure what to trace and where. i've read 'B board' all over the web but nothing specific to this.


i've looked at some of the larger chips on the B board and the solder looks fine. nothing looks burnt out, melted, browned etc.


i tried upping the gain on the brightness setting (thing with the big red wire going in/out). stopped when i saw horizontal scan lines. made no difference.


i know my way around a soldering iron and a multi-meter, but have no other electronic devices/tools to measure frequency and so forth.


do you know the circuit i need to be tracing? or board/area to inspect? this is all very intriguing!


thanks

f

 

[daryl_al]

Hi,


I was wondering if you ever found the solution to this problem.


My Sony KP53HS30 is doing the same thing. I cannot get a pure white.

The color is reddish. Is there something I can do in the System Menu or does it have something to do with the B board?


Thank you very much!


d