Sony Trinitron KV-27S66 - Videokarma.org TV - Video

YamahaFreak · #1 07-01-2010, 03:30 AM

Okay, I've got a 27-inch Trinitron that I really want to get working again. I've posted about this set before (pre AK-VK split) and have had it quite awhile; it was a curb find. Last week, in anticipation of bringing home a 36-inch HD Trinitron for $40, I curbed three sets myself, including a 32-inch Trinitron, all dead. This 27-inch set was saved because it at least tries to start, unlike the larger Sony, which was completely dead (not the AC line fuse, I checked that, of course!) Unfortunately, the HD set was sold out from under me, and now, aside from my little KV-13FS100, this 27-incher is my only Trinitron set. I would dearly love to have it up and running again! Here are the details:

THE SET

Sony Trinitron Color TV, model number KV-27S66
Chassis number BA-4D
Manufactured October 1999

THE PROBLEM

TV will not turn on.

THE SYMPTOMS

When the power button is pressed, a single relay comes on and a faint clicking is heard for six seconds, about four clicks per second. Then the relay goes back off. The red indicator LED on the front of the set comes on and flashes.

PHOTOS

Front of the set: http://www.wolfness.com/up/files/Son...20KV-27S66.jpg
Rear panel label: http://www.wolfness.com/up/files/Tri...ck%20panel.jpg

Any ideas? I might be willing to spend more money than I usually do on a TV to fix this set, and hopefully I can perform the repairs myself.

Username1 · #2 07-01-2010, 06:02 AM

Some of these problems are found by slowly powering the set up with a variac. But getting a schematic and looking at the power supply design is most likely your first step. Relay kicking on and off is some voltage not right, too much current drain down stream, over voltage at the power supply, or possibly high voltage section is not starting, or voltage too high and it shuts the set off. Since it happens a few times a second, you have to do some thinking. Also check the internet for similar problems.

Username1 · #3 07-01-2010, 06:26 AM

Just in case you can't get a schematic, or want to get ideas before you get the schematic I always check the internet. http://videotech.lesterville.com/sony.htm
This place has a few items on sony flashing lights clicking etc. Just type in the model number you will get ideas on stuff to think about. I saw overcurrent stuff, Sony hold down circuites for the HV would also make the set turn on and off. Be sure to check out the section on the Self-Diagnostics incorporated into this tv.

Username1 · #4 07-01-2010, 06:39 AM

Here is a schematic for your tv: http://www.givemefile.net/smanuals/t...file/7962.html
go to this site, type in the letters into the box, then click on the link for the models listed. "Download SONY service manual KV-27S42, KV-27S46, KV-27S66, KV-29AL42, KV-29AL42C, KV-29AL66, KV-29AL66C, KV-29SL43, KV-29SL43C repair manual"
Its a 8+MB file. I downloaded and opened it, and its got all you need, nice file and should get you a good start! This schematic has your chassis number on it.

Username1 · #5 07-01-2010, 06:57 AM

I guess a few of us can download the schematic, and read the Self-Diagnostics of that other site and help you out with ideas on where to go. Good luck !

freakaftr8 · #6 07-01-2010, 10:30 AM

My first guess would be the horizontal output transistor. Count the blink code. it will keep flashing this code over and over. Repost and let us know what the error code is.

YamahaFreak · #7 07-01-2010, 04:43 PM

Thank you muchly, the both of you.

As for the error code, it seems to be flashing three times, but I'm stumped, because there doesn't appear to be a notification for three flashes--just two or four. I guess it'd be closer to four, which according to the first site provided, indicates vertical failure. From the site:

"Standby light blinks 4 times, pauses, and repeats--set turns off. Vertical failure (the horizontal could also cause this since the power for the vertical comes from the flyback)

I am REALLY hoping I don't have a bad flyback, as that tends to be the most expensive part, and the hardest to find. I'm now to the point where I'm pretty confident that I can replace a HOT by myself, as long as I can find an exact replacement

EDIT: I got an error code trying to download the schematic from the givemefile.net site. Hopefully it'll sort itself out soon

radiotvnut · #8 07-01-2010, 05:46 PM

I had a '99 27" Sony that would have sound (no HV) for a few seconds; then, shutdown and the standby light would blink several times. Turned out to be a bad flyback.

If your error code indicates vertical failure, it could be as simple as bad solder connections on the vertical IC. If not, the IC probably died due to bad capacitors in the vertical circuit. Also, if the IC shorted, it could have opened the low ohms fusible resistor that's in the B+ line to the vertical IC.

YamahaFreak · #9 07-01-2010, 06:19 PM

Okay, I went out to do some cosmetic cleaning on the set, and I tested it again to get the error code. It's definitely four flashes, vertical failure. Hopefully that website will start working, or I can get the schematic from elsewhere...

EDIT: Site is working now, I got the schema.

wa2ise · #10 07-01-2010, 09:47 PM

Electrolytic caps often fail in SS vertical circuits. So you may want to look at them. If you remove them, keep careful track of where the + lead and the - lead goes. You don't want to get a replacement in backwards. Do one at a time. That way you are less likely to forget where it went.

YamahaFreak · #11 07-23-2010, 06:18 PM

Working on this set again. Is there any way for me to tell which capacitors have gone bad? I REALLY don't want to remove and re-solder every cap until I find a bad one. >_< IC 541 is listed as a failure point in the diagnostic--is this the horizontal output transistor? Where can I find an identical replacement? What are my chances of having a working set if I replace ONLY the HOT?