Sony Trinitron kv1925R flyback transformer failed
 

Here we have a Sony Trinitron TV model KV1925R that I recently got. The TV was found on a covered porch of an abandoned building. I always wanted a Sony Trinitron TV but have never was able to find one until today. It's very good chance the TV is not going to work the TV has been outside for a while, has been whet, and was covered in leaves. So before I do anything I will be taken the back off and cleaning junk out of the TV. Also be checking to make sure the seat can be safly powered on and tested. I will need luck on this one and will report on what happens. This may take me sometime for me to get around to this TV.

I'd disassemble it outdoors first. You don't want any bugs to get loose in your house if it has any. There might even be a wasp nest in there!
And be sure it is completely dry before you power it up!

It's good advice!
When looking inside, note to see if the chassis is rusted! Also, if that model has the horiz sweep that uses the SG613. Also those CRT's didn't have a long life!

let's start at the beginning I took the TV outside then removed the back off of it. The TV was fairly clean inside but I still did take a paint brush and dusted out the case. Then I inspected the insides of the set and nothing was found to be damaged. So I hooked up a VCR to the TV then I turned on the TV. I'm happy to report the TV works and the CRT is like new at 50% brightness and contrast I could watch the TV out side in the sun. Even if I turned the britness all the way down I could still see a image outside. So the CRT is in like new condition and tv has best picture I have ever seen on a CRT TV. I have found an original remote from eBay for this TV. I used the tv in my bedroom hooked up to VCR,DVD,PS1,Sega Genesis. Not bad for tv that was found outside on a porch. The TV setting in the picture are 50% brightness, 50% picture, 40% color, 50% sharpness.

Many people are tossing their analog sets because they've finally switched over. So they perfectly good working sets.
In some markets there was a remnant of analog still on the air as LPTV's. In the Atlanta market it was a Hispanic station, but now they too are gone (converted to digital).
I find an abandoned set in my area about every three weeks. Just 3 days ago I found this (attached) Sony 25 on the roadside. Unfortunately I don't have the space for it.
You should probably blow it out with compressed air. No telling what you'll find. I found a french fry and a bobbie pin in one. Another had a partially melted chocalate bar that had melted across the pins of the audio chip.
Congratulations on your roadside find!

I got a Sony KV-36FS120 just sitting around collecting dust.

If it don't have tubes in it, i don't care about it!

it's too big anyway! if this thing falls on you, it will KILL you! :scratch2:

Can't be too much worse than my KV-34XS955. That turkey is over 200 lbs and I was able to get it from the suburban to the living room without help besides the doorway which is too narrow to carry it screen pressed to tummy.
I definitely wouldn't want to drop it on my foot without steel toe shoes on...

Will that TV didn't last long. I'm going to have to fix it i was watching it and the TV turned off and wont come back on. The power relay still clicks when try to powerup the set but other then that totally dead. I have done some test and I found fuse F60
2 in the PSU to be open. I will try and find a schematic so i have better chance at fixing this TV.

You are lucky. This is not one of the Sonys from hell ! Actually they are
easy to fix.
Look behind the H output transistor. There was a disc cap ( IIRC 2200 @ 2kv)
that would short & burn. VERY common & also happened to
RCAs & Pannys.
If the HO itself shorted its usually cold joints at the H drive transformer.
Another common problem on most brands.
That will be some things to check.

73 Zeno:smoke:
LFOD !

I have done some work on it and I think I have found out what was causing the short. I used the schematic and inspected ever component that whent to ground. I found out that an electrolytic cap had shorted and once I removed the cap the short cleard. The cap had blown out the bottom and another cap was open so I'm going to replace the two caps and if the tv works I'm just going to recape it because the caps are elna brand and I don't trust them. As always the case I have to order caps no matter how many caps I have I never seem to have the ones I need. There may still be problems with the set but I will try the cap fix first and I will check the disk cap. Also check for bad solder joints. I will be glad to fix the Sony Trinitron because I'm using very cheap 13" Orion form 1998.

I have the same model and it still plays well except it has the "hour glass" symptom that I havent investigated yet. These are great sets!

Your set looks to be early mid eighties vintage. Some Sony’s by than we’re even manufactured in San Diego. The label on the back would say where. That jug from your picture looks pretty decent but looks like a few tracking and white balance adjustments would even improve it some more.

The CRT was made in the USA and the TV was made in 1985.

The picture looks a lot bluer on camera. still could use adjusting but I'm not going to worry about because it's very minor.

Unfortunately the flyback transformer has gone bad I turned on the set and it ran for couple of seconds then toons of smoke came out of the flyback transformer. I have found a replacement and will try and fix the TV.

From what I recollect Sony flybacks were pretty reliable but occasionally they would fail. The HV block that had red epoxy would crack and then arc to ground are what seemed to fail more often than a flyback. That set looks like it would be new enough to have HV shutdown circuitry on it.

This is what happened after I fixed a mistake in the power supply that I made. I plugged the set in and turned TV on the TV ran for a couple of seconds then the casting on side of the flyback cracked an smoke came pouring out of it I immediately unpuged the set. Once it stoped smoking I saw were the flyback blew brown gunck out. I did check bottom of the flyback and insulation has zreo cracks. I have replaced the flyback and set powered on and is kinda working I get a picture but it's very bright and the britness control has no effect nore dose contrast(picture control) on the picture. When the tube is warming up you can see the on screen display but once at full britness you can't. I believe the screen control needs to be adjusted but I'm not sure. I have never worked on Sony before nore have I ever replaced a flyback. I also messed up the tunner some how. I get no reception at all but I believe it was a mistake I made I think I have fixed it but I will no once I test the set.

G-2 usually abt 450 volts.If its high it gives your problem.
If G-2 control is on the FBT check for an unsoldered pin
under it.
If G-2 control on CRT socket check the high ohm resistors (over 1 meg )
on socket.

If G-2 OK check the 3 cathodes of CRT ( KR, KB & KG) Should be in range of abt 120-140 VDC. If very low thats the problem. Report back.

73 Zeno:smoke:
LFOD !

I turned on the tv after fixing the tuner and it is hooked up to a VCR so you get a blue screen. Ok here is the result the I get a blue picture from the VCR and the TV's screen display. The picture is washed out and the britness control has very little affect. I would check the G-2 voltage but I'm afraid I might blow up my meter I only have a multi meter and it's max is 600v. The G-2 can be 375-900v

The 200V line to CRT important. Its also the low end of the G-2.
Check first.

Got the TV working and now I'm going to joy one of my favorite tv shows which is Talespin. Thanks for all that help

The tv still works but do to my lack of equipment and knowledge. The tv is out of adjustment do to me not doing them very good the first time and I was ok whith the picture until I watched some other sets and noticed things being overly bright on this one. As you now I did work on this set and i did adjust the G-2 or screen control but did it on a VCR blue screen. Also the gray scale needs adjusted the raster is slightly blue tinted. The gray scale was out of adjustment when I found the set. I don't know how to do G-2 or gray scale adjustments. Before I being I need to track down a color bar generator/pattern generator and have been looking for one those small portable ones. I will work on the tv once I free up my workbench and I will do the adjustments the tv has super sharp picture and very virbrent color for msot people the picture would be more then watchable in its corrent state. I notice it being to brghit so I'm going to fix it and also the f type needs to have the nut put back on its a little hard to watch TV if the connector is in side the TV. Sorry for any grammar errors I didn't have time to prof read. I will fix any errors I find in this replay when I have time to do so.

For overall blue tint.
No signal, just snow. Warm set up 1/2 hr.
Turn DOWN color level control.
Turn down blue drive to make the pix B&W.
If the blue is already turned down turn UP the red & green
a little at a time to get a B&W pix.
Recheck G-2, there can be some interaction.
Due to age you may not make it perfect but have a good compromise.

73 Zeno:smoke: