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-   -   my crt exploded, 56 packard bell (http://www.videokarma.org/showthread.php?t=262354)

jbivy 08-11-2014 06:57 PM

Quote:

Originally Posted by holmesuser01 (Post 3112256)
Did you remove the tube while you were restoring? I never tightened up the CRT bands terribly tight. Just snug.

Glad you had no more damage than you did. An imploding CRT makes glass go everywhere.

The crt was removed when I replaced the caps and resistors. The cushion on the band was a rotted mess, so i replaced that with three strips of inner tube. I dont think i over tightened it. It was a bit loose and i had to do a tad more. The set worked fine for two years, (used every few months) till disaster struck.

Yep, probably came darn close to 97 in the house. Old brick house that an ice box in winter and a furnace in the summer. Im just going to say the expansion/contraction was to blame, somehow.

Or voodoo. Perhaps i ticked off a witch doctor.

Phil Nelson 08-11-2014 08:14 PM

What a frightening event. Lucky for you the safety glass was there.

I doubt that anyone could tell you for sure what caused it. Maybe a manufacturing defect, maybe the neck was rapped sometime in the past, creating a little stress fracture that finally let loose. Maybe a combination of little things that finally added up to one big thing.

It's a little surprising that there aren't more such incidents, considering how some of these old TVs get jumbled around in garages & basements & attics over the decades, exposed to hard knocks and temperature extremes.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Sandy G 08-11-2014 09:12 PM

Glass is funny stuff. One car dealer I knew, most of his "New Cars" were outside, said every now & then the glass would EXPLODE on a window of a new car. He said it would be where it got the slightest bit twisted, or somehow stressed. Said it would sound like a shotgun going off... Who knows ? I DOUBT it was anything YOU did.

Electronic M 08-11-2014 11:37 PM

Heat can cause strange random failures...Some years back I went on summer vacation and left the AC off. I came home to find my table model Silvertone color roundy sitting at a funny angle and fragments of a black material on the carpet. What happened was that the heat caused one of the plastic feet to shatter out from under the set. :eek:

Lesson learned I try to never leave my sets in un-airconditioned storage conditions.

Was that picture in the first post from after the implosion? If so it seems off to me. Despite the odd speckling (which I'd presume is glass shards from the implosion) the safety glass seems intact, and the CRT face behind it also looks undamaged (which would not explain how the speckling occurred). Also if a hole was not made in the safety glass or the outer layer not knocked loose how did the glass get from inside the cabinet to on the floor in front of the set?

jbivy 08-12-2014 02:52 AM

electronic_m

when you look from the back, the left side and bottom of the crt is shattered. The safety glass is all busted, but only slivers of that came off of it.

walterbeers 08-12-2014 07:08 AM

Hope your feet are OK. Well, now you know for sure what the safety glass is there for. Luckily it didn't implode when it was out of the set. In all the years that I have worked on TVs, I never had one do that. I've had necks crack on CRTs, and once I was working on a customers set in their home (probably close to 30 years ago) and accidentally hit the neck of the tube, and whoosh, had to buy them a new tube, but it didn't implode. When I was a teen, (I'm 63 now) we had an old TV, and to get rid of the tube, my Dad tossed and flung it hard in our back alley, and we had glass 3 houses away to clean up, and it was probably only a 17 inch. Sets back then, years ago like that weren't even in air conditioned houses, but the age of the glass, maybe the band being a little too tight, the rubber around the tube, and the temperature probably all contributed to it imploding. Too bad you weren't wearing shoes!

ronl 08-12-2014 08:36 AM

i have Never seen this happen in all the years (like 1970) of servicing crt tv!
as a kid,i played/stumbled/fixed 50s tvs found cheap at "sally ann".
if i could not fix the $2 50s tv, me and my friends would "blow up the crts" with rocks.(i know-i was a kid at the time).
what amased me at the time was how tough the crts were!
it usally took serveral rocks thrown at the back of the crt to get them to blow!
i even accidently dropped one 21 inch 50s era b&w crt a few feet to concrette and it didnt blow-those crts were tough!
surprised to see this crt blow!
RonL

Username1 08-12-2014 08:52 AM

It's good to hear that you are ok. I would tack it up to removing and reinstalling the tube.
At some point the tube was under some stress that may have begun a small fractue.
It may have been done 50 years ago, any relieved as you put it back, but damage done.
Then temperature cycles over winter and summer finally finished the job. I would imagine
this was a unique example, and not likely to be a trend with older equipment.

Try and be very observant when putting in a replacement, possibly use some contact
cement, or silicon glue to hold the tube against the strapping, and rely less on tightening
the strapping.....

Good luck on the replacement.....

Oh, and I guess above all, be sure you get a proper replacement safety glass.....

.

kramden66 08-12-2014 10:32 AM

the big bang ..... i wonder if any of us are facing this possible scenario , also the metal glass crts , could they go boom in time i wonder.

holmesuser01 08-12-2014 11:03 AM

I've replaced hundreds of CRT's, both B/W, and color, and have never had an implosion. I've never put straps on more than just snug.

jbivy 08-12-2014 02:53 PM

Well the beast is back in my shop/garage. Ready for whenever i get a new crt and can get the glass cut for it.

Oh well, it can sit next to my unrestored 57 zenith tv until i get the time and money to tinker with it.

Im going back to school in september, so this project may be put on the back burner for a while now. But dont worry, ill get to it.

holmesuser01 08-12-2014 03:32 PM

Quote:

Originally Posted by jbivy (Post 3112320)
Well the beast is back in my shop/garage. Ready for whenever i get a new crt and can get the glass cut for it.

Oh well, it can sit next to my unrestored 57 zenith tv until i get the time and money to tinker with it.

Im going back to school in september, so this project may be put on the back burner for a while now. But dont worry, ill get to it.

I hope a CRT comes your way.

Tubejunke 08-12-2014 04:44 PM

I think it pretty much boils down to what Username1 said, and said rather well. In addition I would add that it all could have began with the trip to where you got it and from there to your home. A 24" is a pretty big tube and a set gets turned in all sorts of awkward positions and such when people try to move them. Then there is road/car vibration which is really bad on glass.

All of these things all the way up to tightening that band a couple of years ago could have led to that fateful day. Maybe a flaw at the factory 60 years ago behind all these things and all these years and then the ride and vibration and the tightening of the band. Oh, and the temperature changes or better yet one too many episodes of The Rifleman. Or maybe none of this is true and it was shot by a random drive by shooter and since there is no air conditioning there only remains a spent projectile that got vacuumed up and nobody knows the difference. Seems there was mention of a gunshot, or the sound of one.

OK, wow! I get more like Arlo Guthrie the older I get! Being a little silly, but why not have a little fun. It's a pretty far out story.....

N2IXK 08-12-2014 07:06 PM

But did they get the requisite 8-by-10 color glossy photographs with the circles and arrows and paragraph on the back of each one...?:D

I cannot tell a lie, Officer Obie. I imploded that tube by hitting it with a shovel, a rake, and other implements of de-struction.

Boobtubeman 08-12-2014 07:23 PM

Mouse fart...... DEFINITELY a mouse fart.... An inside job at that..... :D

SR


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