Riddled TV Repair Forum

floridatv · Joined: 03 Jan 2009 Posts: 5 Location: Florida

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

thanks in advance
f

Google

ivtec · Joined: 19 Nov 2008 Posts: 13 Location: ma

Try to raise G2

floridatv · Joined: 03 Jan 2009 Posts: 5 Location: Florida

forgive my ignorance, what exactly is G2 and what does it adjust?

kuhurdler · Joined: 28 Dec 2006 Posts: 2879 Location: Overland Park, KS

open the TV and look for the flyback transformer with the big red wire coming out of it. It should have two knobs on it: screen and focus. Screen is the one that you want to adjust. just turn it to the right until it shows lines on the screen, and then rotate it slowly to the left until the lines go away.

Jesse Mack · Joined: 22 May 2008 Posts: 600 Location: The Last Frontier

This is some information that I have on my computer that Sony has purged from their system. I do not know if this is your problem but it has promise.

3. Intermittently picture gets dark.
Tapping sides and picture returns.
Found cold solder joints on CN3203/pins 49 and 50.

Hope this helps.

Jesse

Google

floridatv · Joined: 03 Jan 2009 Posts: 5 Location: Florida

great, thank you both for the replies. i'll hoist the TV up to my workbench and look at these 2 spots.

floridatv · Joined: 03 Jan 2009 Posts: 5 Location: Florida

hello all,

before taking the back off i wanted to test all the inputs at all resolutions and the output too. 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 now and i will look for the circuits/dials/chips mentioned above.

thanks again
f

floridatv · Joined: 03 Jan 2009 Posts: 5 Location: Florida

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.

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

thanks
f