Found a 36" Sanyo AVM 3659G Won't power up. - Page 2 - Videokarma.org TV - Video

MRX37 · #16 08-08-2008, 11:57 AM

2SD1880 sounds about right! I can make out "880" on the old one.

That'll help if I can find specs...

EDIT: The HOT from the Magnavox chassis apparently won't work. (BU2508DF), no damper diode.

I may try to scrape some cash together and visit a TV repair shop to see if I can obtain the right transistor.

MRX37 · #17 08-08-2008, 01:24 PM

Okay. I put in a Zenith 121-1141-01 HOT from a 19" TV. From what I've found, it crosses with an NTE2302, which after looking up the specs seems very close to what I need.

I put it in the TV and tried it, and the TV's alive again! However, I've only run it for about 30 seconds out of fear of shorting this HOT. The picture was VERY concave...

Can I run the TV like this, to see if this HOT will hold up?

andy · #18 08-08-2008, 02:09 PM

...

MRX37 · #19 08-08-2008, 02:22 PM

Okay, I ran the TV for 25 seconds and turned it off. The heatsink that the HOT is attached to was almost too hot to touch. I guess that means the 121-1141-01 is an inadequate replacement.

andy · #20 08-08-2008, 02:30 PM

...

MRX37 · #21 08-08-2008, 02:41 PM

Could you, or someone else compare the 2SD1880 that this TV needs, to a Zenith 121-1141-01 and see if the specs are indeed similar? If they are, I can rule that out and start looking for what's causing the HOT to overheat.

rcaman · #22 08-08-2008, 03:43 PM

i have been in the repair business for almost 30 years you are spinning your wheels putting anything but what was originaly in the set. dont waste your time with those other outputs put in a 2sd1880 and do the finger test on the heatsink. steve

MRX37 · #23 08-08-2008, 04:16 PM

Quote:

Originally Posted by rcaman

put in a 2sd1880 and do the finger test on the heatsink. steve

Feel like shipping one to me? I'm flat broke, otherwise I'd have ordered one by now.

radiotvnut · #24 08-08-2008, 04:56 PM

I also try to stay away from NTE/ECG transistors, especially in power supply and deflection circuits. Sometimes they work and sometimes they will blow up in your face. Many times, it's actually cheaper to go with the original part than an NTE sub. Like rcaman said, put an original back in there. Another word of caution: Many parts houses sell inferior transistors at a cheap price. Many of these will short instantly. I think places like Tritronics, Mouser, and B&D sell decent parts. I remember finding some STR53041 Zenith voltage regulators at a "good" price. It turned out that every one of them were bad!

You might want to order 2 or 3 HOT's. That will give you some "play room" in case you blow one while troubleshooting.

I'm sure whatever is bad in the pincushion circuit is causing the HOT to blow. If I had a schematic, I could probably tell you some things to check.

MRX37 · #25 08-08-2008, 05:37 PM

Okay... When I can, I'll order the correct HOT, and I'll try to get more then one. I'd prefer to order one with higher ratings to have some wiggle room, but I don't know what I'd order.

I'll just have to hope that the 2SD1880 isn't some value engineered POS designed to fail inside of 5 years...

MRX37 · #26 08-17-2008, 08:51 PM

Ohhhh... I was working on my Samsung TV (cleaning the remote sensor), and I looked at the HOT it has... it says "D1880" on it!

Gah it's tempting to sacrifice it... but I like that Samsung TV. I'd just go and buy a new HOT, but a certain douchebag who owes me money is making up excuses not to pay me.

I'll see what I can do about obtaining a new HOT first.

MRX37 · #27 08-20-2008, 02:00 PM

I staved off the temptation to cannabilize my Samsung TV, and ordered two Sanyo 2SD1880 HOT's

I've been checking the TV for other shorted transistors and can't find any so far. Any idea on where to look?

MRX37 · #28 08-23-2008, 07:00 PM

All right! Got some good news!

I ordered two 2SD1880 HOT's a few days ago, and they arrived today. I put one of them in, and the picture on the TV is no longer concave. I ran it for 25 seconds like before, and the heatsink barely got warm.

What should I do now? Run it for longer?

radiotvnut · #29 08-23-2008, 07:08 PM

I'd resolder the horizontal driver transformer (the little transformer that connects to the base of the HOT) and any other connections that look bad around the flyback. I'd also check the B+ and make sure it's not running high. It shouldn't be over 130-135 volts. Other than that, just play the set and see what happens.

MRX37 · #30 08-23-2008, 07:13 PM

Don't know how to, and unsure if my multimeter can handle checking the B+ voltage.

I'll check the transformer's solder connections, and I think I'm going to beef up the heatsink that the HOT is attached to, as it's rather inadequate in my opinion. I'll take one of my small computer heatsinks and attach it to the HOT's heatsink.