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Sony KV-24FV300 Vertical Foldover

watsonm05

Nov 13, 2010
2
Joined
Nov 13, 2010
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My 7 year old Sony KV-24FV300 has a section of vertical fold-over at the top of the screen. It started out as a couple of retrace lines but has gotten worse.

From reading other threads it looks like I need to replace the (or some of the) caps that are part of the vertical output IC.

Can anyone help with cap numbers / location? Unfortunately I don't have a manual and haven't been able to find a free copy in the internet.

I do have a couple of older o'scopes, DMMs & general electronics knowledge (used to teach introductory Electronics, I'm an EE but I work mostly in digital, software, microprocessors, not much analog).

Thanks,

Mark
 

watsonm05

Nov 13, 2010
2
Joined
Nov 13, 2010
Messages
2
Found Free schematics

Well after posting the original message I did some more searching and found great treasure trove of information.

Its: http://www.schematicsforfree.com

They have a bandwidth limit and request a $5 donation.

I downloaded copies of the Sony BA6 chassis training manual - WOW! - and the service manual for the family of products including mine.

From looking at the schematic (http://www.schematicsforfree.com/archive/file/Sony/Video/Sony Kv24Fv300.pdf, page 31 near labels 12, 13, & 14) it looks like the following caps might be the culprits:

C545 220uF electrolytic (between REF & BOOST of IC545, the VOUT chip),
C544 47uF electrolytic (between VCC+ & VCC- of IC545, the VOUT chip)

Any suggestions before I try to source these parts, tear into the TV & install them?

Thanks,

Mark
 

Resqueline

Jul 31, 2009
2,848
Joined
Jul 31, 2009
Messages
2,848
Go for it. In particular the boost cap sounds like a good suspect. Only on a Nokia have I found a small (100nF) plastic cap to go faulty in the deflection circuits.
I know these Sonys are not in particular service-friendly.. After you remove the back they're left balancing precariously, and it's not possible to measure on them like that..
One has to disconnect everything, replace suspects and then reassemble it before testing..
 
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