sony kv-36fs100 adjustment
 

I recently acquired a rather heavy Trinitron tv and although the picture is decent, it seems to have some issues. I'd like to see if anyone here has experience with these types of tv's and if this one can be adjusted to possibly improve the picture.

What I'm noticing is some color and/or possibly (I'm still learning about CRT's) some dynamic convergence issues. I've tried to read any information I can find about this subject and I have read through the service manual for this model. I'd really appreciate some advice so that I don't end up damaging the unit.

The most noticeable (to me) issue here is the top left corner. It seems to be a bit distorted and is slightly darker than the rest of the screen. Otherwise, it seems like there is a little bit of adjustment that could probably be made along the bottom but its not really that bad.

I've gone through the service menu but I didn't want to go nuts on settings before I have a better grasp of what I'm trying to do.

For the following I used a Wii via composite to display the patterns from 240p test suite, and an SNES via component for game shots.

https://ibb.co/3NCKBHM

https://ibb.co/NVswhL0

https://ibb.co/ZmJrT4R

https://ibb.co/2Fx9btG

https://ibb.co/zQnbsdq


Back of the tube during cleaning/inspection:

https://ibb.co/sgxF60w


Thanks in advance for any advice or information that can be offered, even if it's just saying that this unit is junk.

My back hurts just looking at that thing. Saying a 36" flat CRT weighs a ton is an understatement!

:yes:

It was quite a task getting it here from the person's home it was previously in. What's worse is I don't currently have any sort of stand or table that I'm certain will hold this 216 lb beast. Needless to say, it's living in my garage until I can build or acquire something sturdy enough to hold it.

First off the CRT looks very strong. Hard to tell but it looks like
the purity is off. On the CRT all those little squares glued on are correction
magnets. See if any fell off. There is a chance the shadow mask in
the CRT has broken loose also.
You need a source that can give you a pure red, blue or green screen.
If the screen is say green but the corner area is not its a purity problem.
Look into that & get back to us.
BTW almost all service adjustments are through a menu. You need a remote,
possibly OEM & instructions or you can mess things up bad. I see NO reason
to mess with them anyhows.

73 Zeno:smoke:
LFOD !

Another way to check if the purity trims are not quite right is to rotate the set and cold/hot cycle it to make sure the degaussing coil operates fully. In other words, if the set is facing north/south now, try operating it when facing east/west. If the upper left changes somewhat, it's another indication the purity trims are off a bit, especially if rotating it back brings it back to this same condition.

If the mask is loose, I'd think jostling the set by moving it would produce much worse results.

I was wondering why there were so many magnets glued to this thing... I remember other crt tv's I had in the past had way more permalloy strips but almost never a bunch of correction magnets like that.

I'll find a way to generate pure color to the screen and see what it looks like, especially in that top left corner.

Fortunately, I have the remote and it seems to still work fine. The service menu on this thing seems much more extensive than any other units I've owned before.

Thanks for the advice. :thmbsp: I'll update once I've done a bit more investigation/testing.

Thanks for the response. I'll definitely give this a try and see what results are produced. So does the unit normally energize the degauss coil at every startup?

Only after a cold startup, you would have to let it sit for about 20 minutes for it to activate the thermostat or for the degausing field again.

Usually this is described as a loud hum or buzz when 1st turning the TV on you can hear the field energize. When you turn it off and turn it back on all you get is a subtle click and another click and then the picture comes on this means that the field did not energize.

I'm also noticing that in the cross hatch pattern, the picture appears to be vertically bowed. This can be from the yoke being slipped down, not positioned correctly, or the VBOW setting in the service menu IIRC. Dont get confused with YBOW. That's for convergence.

It's amazing for all that weight that there isn't much of a chassis anymore. By the nineties all the pots they had on the older sets for adjustments were gone. All done with stored memory locations and changed via the remote control. This was the point I lost interest in doing service as I liked all the adjustments from pots that you had all those years. Is this part of the Sony FD era? I have a 32 inch Sony from '95 and it's the same as far as adjustments go. Wondering if PIP (picture in picture) would of still been a feature on this model.

I would need Crane to move 36" flat tube tv or a bad back

The original user manual I got with the tv says it is an FD unit and that PIP is a feature. A sticker/label on the back of the shell says November 2002 so maybe a number of things didn't really change much on these from the mid 90's to early 00's.

With two people that are in decent shape and of at least moderate physical size, the weight of the unit wasn't too bad. However, the logistics of moving it around and over obstacles was a different story.

I like to think about how incredible it would have been as a kid to have a tv like this to play games on. I mostly had cheapo RF-only 13" tv's that looking back were in a different universe than this one.

Update:

Since I'm still waiting on the 240p test suite cart and component cables for my Genesis to show up, I decided to hook up the Wii today and take a few more pics.

https://ibb.co/xLPC9bZ

https://ibb.co/gRG4zqp

https://ibb.co/bJ6mcqF

https://ibb.co/zZsV4Fv

https://ibb.co/Rbf6sxt

That test screen that's supposed to be solid white seems very off.

I went back through the service manual and did a little bit of experimentation with some of the settings in the service menu. I didn't commit any of the changes because none of them really seemed to help with that bow in the middle of the screen at the top.

I rotated the TV in place and ran a couple cold power cycles. After I first moved it, I turned it on to the tuner and in the static there were noticeable colors in the corners. After another power cycle, they were gone.

After a more thorough check of the back of the tube and around the chassis, I determined that there didn't seem to be any dislodged magnets.

I have some sheets of magnet material for making fridge magnets. I wonder if that would be sufficient to make some adjustments on this tv.

I still think your yoke position is off. Yoke slipped back and is tilted down. I'd try to press up on the bottom of the yoke and look for noticable changes.

I was finally able to get back on this and I believe you are right. I don't have a mirror that I can put in front of the tv but I did have someone watch the screen for me while I pushed up on the yoke. They reported that the bowing seemed to clear up quite well, especially around the top of the screen where it was especially bad.

Now I just need to figure out how I want to make this "adjustment" permanent. I noticed there are rubber wedges glued to the tube all around the yoke. Perhaps I can reposition some of these and adhere them in place. Not sure which adhesive would be appropriate for that though.

Maybe you don't need to reposition the weges but just push the yoke up against them?

I considered this but I'm not sure how it would stay in place if the unit needs to be moved. Would it fall back down and require adjustment every time? Admittedly, I'm not certain how the yoke is held in position from the rear so that could be why I'm struggling to figure out how this would work.

To clarify, when I was pushing up and slightly forward on the yoke from the bottom center, it had a decent amount of upward movement, but if I let go, it would fall all the way back down to its "original" position.

Loosen the lock down clamp from the rear of the yoke and push the whole thing forward to the bumper stops. There should be 3 wedges.. One on the top center and two on the bottom all spaced evenly. Once you do this, you will probably have to turn the yoke a tad to correct a tilted picture. But should fix your problem if the wedges haven't physically came unglued from the crt and moved.

Another way to do it would be to physically remove the top wedge and while pushing the yoke up from the bottom put the wedge deeper into the void there to sustain the yoke angle

This has fixed the bowing issue. I noticed that whatever adhesive was used previously to hold the wedges was not holding very well anymore. I will probably use some sort of RTV since I've noticed that seems to be what is used in other units I have gotten recently.

At this point, I'm trying to figure out if I can fix the issue in the corners. It is very noticeable that if any sort of text or high contrast images are displayed in the top and bottom left, the colors seem to be separated. According to the service manual, this can be adjusted with permalloy strips or probably whatever I can make that's similar enough.

Yes. This is what you want to do. Maybe go find a few small low power puck style magnets and attempt to position them on those areas on the back of the CRT to align the corner convergence. it's tough (and dangerous) so be careful. Try to hold the magnet with some insulated pliers and take note not to drop the magnet on the PCB or yoke windings. That would be bad. But if you can find an area that will align the corners, stick it there. Its tricky and if the magnet is too powerful, you will feel the energization of the CRT so use insulated pliers. I've done this before with mixed results.

The yokes were bonded to the tube at the factory on these no?

Also I recall when these came out there was a warning about not using a degauss coil on them.

Not a bonded yoke.
You can use the magnets from a refrigerator door gasket. Also
when you junk a set save some. Move & turn the magnet while
watching then glue or tape down. Try about a half inch piece to
start. This all assumes the purity is set right. Moving the yoke
back & forth along with neck magnet setting sets it.
BTW if you mess with the neck magnets mark them FIRST !

73 Zeno:smoke:
LFOD !