Panasonic Burned Up! - Videokarma.org TV - Video

jstout66 · #1 08-28-2015, 08:43 AM

Well.. I had a scare when I got home last night. Walked into the house and could smell a distinct burning electrical smell. I of course am bad and have about a zillion things plugged in that I don't use all the time. Went into the basement and figured out it was this late 80's early 90's industrial Panasonic TV/VHS combo. I figured it out because the display wasn't blinking. Any idea what could have happened? I'm wondering if I did a stupid thing and this has been turned on for god knows how long. If there is no video source the screen goes blank and there is no audio. Or... if it was some freak thing. Any idea's? (ha.. and go figure.. my attachment is numbered 666 on my camera)

zeno · #2 08-28-2015, 09:30 AM

I dont remember the innards but.....
most likely the flyback.
If its the same chassis as the consumer model
look for shorted hoz out, disc cap near it 220pf 2KV IIRC,
SRT & resistor in power supply, fuse.
Just gotta open it up. Dont forget chassis pixs.

73 Zeno

jstout66 · #3 08-28-2015, 09:35 AM

Will do Zeno. We had a severe thunderstorm roll thru yesterday, but it shouldn't have been on, and everything else in the house was fine. I hope I wasn't senile, and this thing has been on for months without me knowing it.....
Any ideas if it could have burned up without being turned on? (switching supply or something)

Findm-Keepm · #4 08-28-2015, 10:05 AM

If you took a surge from the lightning, the MOV across the power line could have eaten it - they too stink when they go.

The industrial stuff would all have MOVs - it became UL coded mandatory in the early 80s.

jstout66 · #5 08-28-2015, 10:50 AM

That's interesting to know.
It was an ODD day.. Went home for lunch and discovered the dog had broken down the baby gate (probably due to storm) she had also flung her dog bowl and dog bed down the stairs. I noticed a little blood on the door-frame (possibly when she broke out), and than I get home from work and smell that. It was not unlike the smell from a CTC-38 when the flyback went.
I'm trying to figure out what made the dog freak so bad. Would the set have let out a loud pop when it went?

Findm-Keepm · #6 08-28-2015, 11:10 AM

Most MOVs fail spectacularly - we had one across a 440V line in a test station that went when some idiot lifted the neutral in a junction box. The MOV let out a loud POP, then bluish smoke with the smell of burnt plastic. The MOV was originally the size of a Cigarette pack, but all that was left was tiny pieces attached to the connection terminals, and the metal base. The rest was deposited as soot and plastic around the power input area. Mess...

I had a power strip that got juiced in a storm, and it went out with a long whistle with the charring smell, little smoke. Startled me, for sure. Nothing was plugged in - I was using it earlier as a 24-inch extension cord for my drill to drill a hole in the ceiling near the center of the room.

If it was the fly, some go up in smoke, and some Sharp flys would whistle (RTRNF0038CEZZ - replaced a few of them!). Some big can Electrolytics fail even more spectacularly - had one in an old AN/USM-207 Freq Counter spray tar on the ceiling tiles in the lab (with 12 foot ceilings!!) - I'm sure glad no one was around when it spewed.

old_tv_nut · #7 08-28-2015, 01:44 PM

Your dog could have been reacting to the smell even without any noise, not so?
Sorry to hear about your trouble.

zeno · #8 08-28-2015, 02:36 PM

Ah lightning, used to pray for it

Then power transformers
went away

No longer a gravy job.
MOV & violently blown fuse with luck. Also look under the
PCB at the AC cord. Panny used printed spark gaps &
they really fry & need cleaning up. May also use a small STBY
transformer that opened. If not the SMPS is next.
Be VERY careful spending $$. Often the surge destroys the
set.
BTW does it have tuners & was anything else hooked to it ?

73 Zeno

jstout66 · #9 08-28-2015, 02:46 PM

No worries... I'm not throwing money at it, unless it's a simple fix. I bought it years ago because it was odd. It does have a tuner, but it's an odd.. not cable ready type. Or if it was, I could never figure it out......
I never thought the picture was that good on it either. It reminded me of a Porta-color. The dot pitch on the picture tube is WEIRD.
It's just odd that ALL my stuff was plugged in, and even other stuff on that surge panel, and everything else is fine.

walterbeers · #10 08-28-2015, 05:55 PM

Hey, how many times have I told you (and others) not to ever leave these older tube sets on, or even plugged in unless your there to "babysit" them. Please don't take that bad, though, it's happens to be best of us, even me. Could be many things, but most likely the flyback went. Although this set probably does have a MOV, most likely that isn't the problem. Lots of even older TVs have a capacitor across the line, for RF filtering, and I have seen one of them blow once while unattended. Went off like a fire cracker. Funny thing was that the TV was still playing just fine. If I remember right it was one of those ceramic encapsulated paper capacitors, and rolls of foil was all over the underside of the chassis. PS, it was a Sears (Warwick) made all tube type set. Many of the old radios back in the 30's and beyond didn't even put a fuse or anything in them. If something shorted, Bye, bye power transformer. Bring it over, I'll check it out.

radiotvnut · #11 08-28-2015, 08:07 PM

I can tell you that Panasonic flyback transformers often go out with a bang and smoke. They'll either crack and arc out the side of the transformer or they'll simply go BANG, smoke, and leave a big crack in the case, with windings hanging out of the crack.

Electronic M · #12 08-28-2015, 08:35 PM

Quote:

Originally Posted by walterbeers

Hey, how many times have I told you (and others) not to ever leave these older tube sets on, or even plugged in unless your there to "babysit" them. Please don't take that bad, though, it's happens to be best of us, even me. Could be many things, but most likely the flyback went. Although this set probably does have a MOV, most likely that isn't the problem. Lots of even older TVs have a capacitor across the line, for RF filtering, and I have seen one of them blow once while unattended. Went off like a fire cracker. Funny thing was that the TV was still playing just fine. If I remember right it was one of those ceramic encapsulated paper capacitors, and rolls of foil was all over the underside of the chassis. PS, it was a Sears (Warwick) made all tube type set. Many of the old radios back in the 30's and beyond didn't even put a fuse or anything in them. If something shorted, Bye, bye power transformer. Bring it over, I'll check it out.

Anything tube that don't have instant on, and has had it's line RF filter cap changed I trust more than anything you can buy new since the power switch actually disconnects everything from the line (versus SMPS that are always drawing power and feeding power through parts less reliable than a switch).

kf4rca · #13 08-29-2015, 08:14 AM

of a lightning strike nearby. I'd get up on the roof and check everything out. But to protect your home and everything in it, I recommend installing a whole house surge protector.
They're easy to install on the meter box and protect everything downstream. (Power company requires you to install them on your side of the meter.) They're about $40.

jstout66 · #14 08-29-2015, 08:42 AM

I'm going to run this over to Walter's today and we shall take a peek inside. I did find a flyback on eBay for 15.00 if that indeed is what the problem is, so will debate once it's opened up. Does anybody have a Sams they can scan? It's Model AG-560.

WISCOJIM · #15 08-29-2015, 09:16 AM

Doesn't appear as though there is a Sam's for that model.