Sony KV32V65 power-on problem - please help

tech0128 · Joined: 29 Jan 2007 Posts: 3

I have a power-on problem with a Sony KV32V65. When hot it powers up fine with 2 blinks but occassionally (when cold) it will do 11 blinks and then display an image. Recently it just blinks continually and has sound and tuner but no picture. The following deductions have been made.

1. No problem with bus since sound is always ok and channels can be switched just no picture
2. Poking, prodding and examination has not found any cold solder joints or foil problems
3. Flyback and picture tube and probably OK since G2 adjustment has not done anything

However after switching the set on and off many many times it finally powers up at 2 blinks and works without failure. I suspect either a leaky cap or some other component that finally gets enough current going thru it to function. I have a schematic. Can anybody give me any clues as to which part may be the suspected problem ? Is there any failed part that has seen consistent repairs on this particular set ? Thanks for any and all comments.

minnie · Joined: 18 Aug 2005 Posts: 2880 Location: Hell

Check R607 and see if it's open.

tech0128 · Joined: 29 Jan 2007 Posts: 3

R607 is good. The problem is that when the set is first turned on after being off for many hours it will blink 11 or 12 times and the picture will come on. Then after about 20 seconds the horizontal is lost and the picture shrinks up to the top of the screen. However if I turn the set off for about 10 seconds and then on again it does not blink and comes on instantly and will work find until the next time if is off for many hours. It seems to be that when the set is turned on and off a few times the problem goes away. Its like something is getting energized after a few cycles of on and off. Is there any specific electrolytic cap that may be going bad ?

Frank · Guest

Check and Esr all caps in the power sup,

TigerWood · Guest

Sure sounds like your CRT is weak. You need to rejuve your picture tube. Sencore CR7000 or equivalent is required for this procedure. If you don't, you are pretty much out of luck. Hope this helped you.

minnie · Joined: 18 Aug 2005 Posts: 2880 Location: Hell

Sound with no picture is a typical resolder the vertical ic. Common in all Sony's.

TigerWood · Guest

Oh, now I see that his picture was intermittently shrinking from top when cold. Yes, you either have cold solder on vertical output ic or faulty ic itself. One of those two should solve your problem.

tech0128 · Joined: 29 Jan 2007 Posts: 3

Where is the vertical output IC located ? Can you help me identify it as a small chip or a large chip or what it is close to ? Is it on the main board or one of the smaller boards connected to the CRT neck or do you have the IC number that I can reference on the schematic ? Is this a common problem with Sony tv's ? Thanks for your help.

gilloz · Joined: 03 Feb 2007 Posts: 33 Location: So. Cal High Desert

If your schematic does not have a pictorial and /or listiing of parts, of the motherboard layout, then follow the output line from the Vertical IC shown on your schematic and it should go to the Vertical Deflection coils after going through some discrete components in the line. Your schematic should have a part identifier called out and the motherboard should have it printed near the component. It will probably be a 24 pin IC, but then again they vary with many brands of TV's.