Sony KV-5100 Add pincushion circuit

[Devicemodder]

Hi all, i would love to add a pincushion circuit to my KV-5100. the traces are on the board, but the parts were never populated from the factory. Cant find anywhere in the service manual schematics for the components i need to add. what parts are needed?

The PCB has a place for a pot labelled RV505, but there is no RV505 in the service manual,

I have attached a pic of the area in question. (bottom left of pcb)

[Alex KL-1]

For some models/CRT type they opt for not using it since some CRT have less neet for fine correction but, is possible then to add ALL parts for pincushion control - make sure the diode, caps, resistors and transistor for controlling the pincusion are present.

[Alex KL-1]

Note: is good to check if this model have passive (RLC) circuit with a special inductor; this dispenses with the active correction.

[Devicemodder]

Originally Posted by Alex KL-1

Note: is good to check if this model have passive (RLC) circuit with a special inductor; this dispenses with the active correction.

This unit seems to have an inductor, but I have bad pincusion on the set. Oddly enough, the inductor doesn't show innthe service manual either.

[Devicemodder]

Originally Posted by Alex KL-1

For some models/CRT type they opt for not using it since some CRT have less neet for fine correction but, is possible then to add ALL parts for pincushion control - make sure the diode, caps, resistors and transistor for controlling the pincusion are present.

Thats the thing, I don't know what transistors, diodes, resistors, or caps I need to do the mod, as they aren't listed in the service manual. Hence my post here

[Alex KL-1]

If a schematic for a higher sized sister model exists, will be interesting. For TV's from early 2000's, you find schematic for 14~20" not having pin correction (E/W), but for higher sizes it have (the remaining of circuitry is identical exception for the flyback or PSU voltage). I dunno about this old model.

Or worst. If Sony dismissed the pin correction for all of it's models for this year, for example.

[Devicemodder]

Originally Posted by Alex KL-1

If a schematic for a higher sized sister model exists, will be interesting. For TV's from early 2000's, you find schematic for 14~20" not having pin correction (E/W), but for higher sizes it have (the remaining of circuitry is identical exception for the flyback or PSU voltage). I dunno about this old model.

Or worst. If Sony dismissed the pin correction for all of it's models for this year, for example.

found this on an old archive from this site:

drchucksgas
07-22-2011, 04:10 PM
Hi Guys, There is one other very significant difference between the two. The 5000
has an adjustable pin cushion circuit which due to the bean counters at Sony, was left out in the 5100 with simply a factory preset value in it's place. The reason I know this was that my 5100 which I purchased new in 1980 had a terrible pin cushioning problem and I battled with Sony to get it rectified. There was no simple "return the set and get another". These sets were newly discontinued at the time and finding the one that I have was a daunting task. Remember there was no internet and Ebay where you could simply do a search. I searched the old fashined way by visiting as many tv and appliance stores as I could and also letting my fingers do the walking through the Yellow pages. I finally found one but it had a shattered picture tube, so the seach continued until I found one place in New York City that had their last one. I ran down and grabbed it. So anyway, at first Sony said there was nothing they could do because there was no adjustment for pin cushioning. I made it clear that I found that answer unnaceptable and so after much deliberation and arguing, Sony in Long Island City, New York performed surgery on my set, installed a pin cushion circuit and adjusted it to get my picture straightened out. The other problem I had was that the battery back BP-51 that was supposed to last for about 3 hours only lasted about half that time at best. After a bit of pursuasion they also took care of that for me as well.

source: https://www.videokarma.org/archive/i.../t-251345.html (4th post from the bottom of the page)

[ARC Tech-109]

Looks very similar to the Sony BVM-5300 triple monitor deflection board, these were used in the early to mid 80's and notorious for deflection issues. I'd strongly recommend replacing ALL of the electrolytics before chasing a pincushion error, I have two of the triple monitors and they all have some degree of pin error that will not go away no matter how it's adjusted. The RV506 pot is 10K and cap is 1uf @50v in my 5300 and I believe it adds a parabolas to the vertical amp. When you recap replace C506 with an electrolytic not tantalum.

[Devicemodder]

Originally Posted by ARC Tech-109

Looks very similar to the Sony BVM-5300 triple monitor deflection board, these were used in the early to mid 80's and notorious for deflection issues. I'd strongly recommend replacing ALL of the electrolytics before chasing a pincushion error, I have two of the triple monitors and they all have some degree of pin error that will not go away no matter how it's adjusted. The RV506 pot is 10K and cap is 1uf @50v in my 5300 and I believe it adds a parabolas to the vertical amp. When you recap replace C506 with an electrolytic not tantalum.

Recapped the rest of the electrolytics the other day, picture looks brighter, but still having pincusion issues. i'll put the pot and cap in place. are there any other parts i need?

[Alex KL-1]

Probably miss some parts. When several parts are needed for a factory recall mod they will tend to respond like Sony did.

[Devicemodder]

Originally Posted by Alex KL-1

Probably miss some parts. When several parts are needed for a factory recall mod they will tend to respond like Sony did.

So... how do I go about finding what these parts are? They aren't listed in the service manual.

[Electronic M]

Originally Posted by Devicemodder

So... how do I go about finding what these parts are? They aren't listed in the service manual.

Find the Sam's or Sony service manual for the other model number mentioned above that uses the same board but has the pin cushion circuit populated and give it a read. It should have the info you seek.