Weird problem with Sony KV-20FV12

[Dude111]

Is there anyone in your area that could look @ that set for you buddy?

I feel terrible for you,dont want you to lose her.....

[Electronic M]

Originally Posted by Dude111

Is there anyone in your area that could look @ that set for you buddy?

I feel terrible for you,dont want you to lose her.....

Dude...It's just a 15 year old BPC!...I can go out any day of the week and get 10 working ones just like it for free....Hell when I see a BPC on the curb I don't even test it (if I even stop), but instead just rip out everything except the cabinet and CRT to use as parts for mid 70's and older sets that actually have some value.

[zeno]

No need to quit yet. Lets do some free stuff first.

Use a pattern no a changing source. Color bars etc.

Measure the 200 V source. To find it find 3 resistors that
go from the collectors of the 3 color outs. Typically they
are 18 K 2W +- where they join is the 200V.

Turn down the color, brite & contrast all the way.
Turn down the G-2 until you see NOTHING. The paint
will crack when you turn it hard.

Measure the collectors again. If the AKB is killing the
pix they will be 200V.

Trick for all Sonys with AKB for all listening.
Put in video mode no source.
Ground one end of a 15-18K resistor.
One at a time put the other end on each color out transistor
collector..
This makes a voltage divider that will turn that gun on heavy.
A good CRT will show just that color BRITE & usually with
retrace lines. A bad gun will give a dim & mucky pix.
Reds will look brown etc.

Trick 2 last resort.
since Sony CRT's wont rejuve find the low ohms resistor
in series with the filament & short it. Works on most
brands with low E. Risk is an open filament or H-K short but
whats to loose at that point ? We did quite a few & got a year
or two out of many sets.

73 Zeno

[old_coot88]

Thanks Zeno. But I'd already closed the thing up ready for the scrapper. I really have no interest or incentive to repair "new" stuff if the problem isn't obvious and quickly fixable.
Intransigent fuddyduddy-ism.

[kf4rca]

I rejuvenated the tube and it quit cycling.

[Dude111]

Originally Posted by Electronic M

Dude...It's just a 15 year old BPC

I hear ya buddy....

[old_coot88]

Just a little update regarding this critter. I had it all buttoned up ready for the scrapper, and then got to thinking what the heck, just use it like it is for a while. So I ran it with that horrible grey scale, near-zero emission, crappy crappy picture for several days. Danged if it didn't start "coming back to life" on its own over a period of several more days. I never touched the drives or G2 at all. Never adjusted anything. It came back to displaying a fully 'new set' picture just like it always had. And it's been holding that way ever since. Never seen 'nuthin' like it before. Don't know how long it will last, though.
Screen shot attached.

[Dude111]

Originally Posted by old_coot88

.....Don't know how long it will last, though.
Screen shot attached.

Excellent!!!

I hope she is happy now and will give you excellent quality for along time

[old_coot88]

Yeah, hope so too. When it was doin' the original 'cycling' act, there was no perceptible change in the heaters' normal healthy orange glow. A "Lazarus" CRT is real puzzler for sure.

[zeno]

Newer sets do some strange crap. I had a few of this vintage Sony
with a small ( H & V ) & messed up raster. Who would suspect a bad tuner ?
The data line to the tuner would short & none of the IC's such as
the jungle would get the preset data from the E-prom. So you had to
change the tuner / IF & it just cost too much. Odds are it was a
chip in the tuner shorted but probably a SMD & not available.
BTW to trouble shoot just unsolder the CLOCK, DATA & ENABLE
pins at the tuner. If it gives a full raster its the tuner.......

73 Zeno

Originally Posted by old_coot88

Yeah, hope so too. When it was doin' the original 'cycling' act, there was no perceptible change in the heaters' normal healthy orange glow. A "Lazarus" CRT is real puzzler for sure.

[dieseljeep]

Originally Posted by Electronic M

Dude...It's just a 15 year old BPC!...I can go out any day of the week and get 10 working ones just like it for free....Hell when I see a BPC on the curb I don't even test it (if I even stop), but instead just rip out everything except the cabinet and CRT to use as parts for mid 70's and older sets that actually have some value.

You might be seeing more "curbside setters" as Best Buy quit taking in TV's and computer monitors for recycling, free. They now going to charge $25.00, just like others do.