Sony repair help...
 

I've got a friend who is the greatest guy ever, but he's broke and putting himself through college, and the only TV he has is broken. Yesterday I saw a newer Sony on the curb, and grabbed it.

Its a KV-24FV300 with a BA3 chassis. When you turn it on, you hear the degauss and then the HV starting, but then it shuts off and the light starts blinking, and settles into a 2 blink pattern. I searched all over the net, and found the service manual, and that the code means B+ over current. I looked around inside but I don't see anything burnt or out of place.

I can replace parts, but I have no idea where to start troubleshooting it. I'd really like to make this work, my friend would be really happy :banana: I have the service manual if anyone wants to look at it, but it's too big to attach so I'll email it if anyone wants to look at it.

Thanks Ted

I'll bet the flyback is bad. A friend had a '99 Sony that went from working perfect one night to doing what you said the next morning. A new flyback solved the problem. How old is yours? I think even the newer WEGA's tend to blow flybacks.

Manufactured in Feb. of 2003. Where would I be able to find find parts for this set? I was trying to look and see what prices would be like but I can't find anywhere that will sell to the public.

-Ted

You might try www.tritronicsinc.com or www.electronixonline.com . You'll need the part number off the flyback. I think Tritronics is set up so where you can enter a model number in and view the entire parts list for the set.

I looked at the set, and there are multiple different numbers on the flyback. I looked up the ones I could see without being a contortionist, and didn't get any results, so I looked up the model number on Tritronics website.

They show this as the correct part, as well as two other non-sony replacements made by ASTI and DIEMEN. Do you think that any of the other generic replacements will work ok, or should I stick with Sony? I'm leery to spend $82 on hopefully fixing the set w/o testing to prove that its bad, unless this is really that common...?

Thanks radiotvnut, your help is great, and thanks in advance to anyone else who chimes in to help me out.

-Ted

I've heard that the HR Diemen generics are decent. I replaced the flyback in the Sony I mentioned above with a cheap generic and it's still going as far as I know. But, some generics don't hold up. I used one of those ASTI brands in an RCA and the part blew up after two hours of use. I think I'd go with the HR Diemen brand and take my chances. While you've got it apart, check the horizontal output transistor with a multimeter and make sure it's not shorted. It's a big black transistor mounted on a heatsink close to the flyback.

Ok, I'd much rather go for the HR Diemen since its only $38 vs $82 for the Sony part. Their website says its the "Best transformer in the world"... not that I will believe that until I see it for myself. I'm gonna be busy for a bit so I probably wont get to ordering until next week, and I'd like to check the HOT before I do as well.

Is there a specific pattern of tests for the HOT or do I just try every way I can?

Thanks Ted

I've had good luck with HR, but I did fix a set that had a bad new HR flyback installed.

i do a lot of tv repair and we have been using only HR Diemen flybacks and i have not had a bad one yet. steve

Maybe give "Global Electronics" a call and see if they have the entire PC board for this thing. Sometimes they have a surplus of boards that they blow out really cheap, and this makes for a quick easy repair.

1-800-668-8776 (www.globalsemi.com)

B+ overcurrent can be caused by any number of things . I believe your Sony may use a HV multiplier and a focus rect. block instead of a flyback. The first thing you have to verify that the problem is not the B+ power supply itself. Next verify you have not got a shorted horizontal output transistor.Don't go wasting time throwing parts at the set in a shotgun fashion.Do some old fashion troubleshooting..:D
Sonys were notorious for cracks in the PC boards especially around the heavier components . Look closely for cracks in the horizontal section around the HOT heatsink.

I agree, shotgun parts replacement is never the best idea, but I have read in more than one place about flyback failures on this same model set. Still, you're right and I will poke around a bit and check the HOT and for cracks in the board. Hopefully I can get to that real soon, but all this other garbage called "working for money" gets in the way.

-Ted

So i finally got to working on the set again... I was trying to test the HOT but the in-circuit values make no sense and I can't unsolder it. I have a good Weller temp controlled iron and everything. I can get the "top layer" of solder but no matter how I heat it or hold the solder sucker it just wont go. Any hints?

-Ted

Get some desoldering braid. Radio Shack or any electronic supply store should have it. It will still be a slight pain; but, it will do better than the solder sucker. Radio Shack also sells a desoldering iron that sometimes does pretty good.

I agree, I've had the best luck with the braid.
Mark