my crt exploded, 56 packard bell
 

So its 97 degrees and im attempting to nap on the couch, I hear a boom which to me sounded like a .38 being fired off. I stumble around and cant quite pin point where that sound came from. Then i notice my feet were bleeding..

I look at the floor and realize id passed my 56 packard bell tv and that the safety glass was shattered but mostly in one piece. After my wife cleaned and bandaged my feet, we swept and pulled the tv out of its nook and realized the dang crt exploded and thats what shattered the safety glass. Now this tv hasnt been used in six months, not after it was restored and used for a black and white movie marathon.

It was unplugged, why the heck did the crt implode on me? Was it because it was a real hot day or? Perhaps theres gremlins in my home.

Any idea why an unplugged tvs picture tube would just pop like this?



http://i61.tinypic.com/28jee4n.jpg

Wow.

What size CRT?

Only wild speculation here to start:
Could the CRT have been badly scratched at some time?
Is it posible something was tightened with a sharp pressure point (like a mounting point that had a deteriorated soft pad of some kind) that eventually got too tight due to temperature?

Let me get this straight... are you saying that the safety glass shattered *first* then *after* you cleaned that up the CRT imploded?

jr

old_tv_nut

I believe this was a 24" crt, ill dig out the photofacts tonight and find exactly what size and type thistube was. Best case scenario, it was used in a few tv's, so theres a chance i can find another out there.. The strap that held the crt in place had a deteriorated rubber pad. I "cured" that with using a few strips of inner tube glued to that band, so it would cushion the crt.

I saw no scratches on the tube itself during the restoration and didnt think i over tightened anything, though heck, maybe i did.

jr_tech no, the crt had exploded and took out the safety glass all at once. Sorry if i didnt make that clear.

Frankly im just severely ticked off that this happened and unsure if im too blame or its just a natural accident.

Do you have central air conditioning? ... perhaps very cold air blowing on the front of the TV in a warm room?

jr

Ive a few fans blowing, but no air conditioning, the fan wasnt even in the direct path of the tv. All i can guess is that the near 100 degree heat somehow did it.

Open window, and neighbor kid with bb gun?http://www.audiokarma.org/forums/ima...es/pistols.gif

I've had CRT's let go for seemingly no reason before, but none explosively. Mainly cracked neck glass, but it's always due to stress in the glass that hasn't been annealed out. All it takes is the right combination of temperature gradients, and BOOM! My main guess is that sometimes if you watch the set for short periods, the glass near the hot cathode gets hot while the rest of the tube is relatively cool. No idea what caused your tube to let go, but I bet you needed new drawers...lol

Wow, glad you're okay. What an experience!

Yeah, glad you are OK, besides your sore feet. Scary to think that I've got loose CRT's and chassis scattered around our basement, and we're down there amongst them often. I have this weakness for watching a set out of the cabinet, so I can see all the tubes glowing.

That must have been one HELL of a fart... :D

Thats a scary senario...

SR

There are massive amounts of pressure on a 24" tube, maybe some small defect finally let go after nearly 60 years. The only other point of stress I could imagine would be the band, it wouldn't be hard to over tighten I think but it seems odd that it would be okay this long then let go. Perhaps the heat expanded the CRT and increased the pressure.

At least the safety glass seems to have done it's job for the most part, seems to have contained most of the glass?

Well the Photofacts is.. somewhere. I checked the label on whats left of the crt, it says this is a 24aep4. From looking online it seems that a few tv's used this. Some motorolas, sylvanias and packard bells.

So I suppose I have a chance at finding another one, probably from a donor set. Though ill need a sheet of safety glass cut for it as well.


Im glad to hear that its rare for these old crt's to "grenade" like this, since this did scare the pants off me. I didnt need to change my drawers, but it wasnt the nicest way to wake from a nap. lol

Yes Im glad you were OK........... I hope it wasnt 97º inside!! (That might cause something)


Im so sorry buddy!

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.

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

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.

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?

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.

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!

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

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.....

.

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.

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.

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.

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.....

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.

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

SR

Mbwahahahahahahaha.. Gotta love some "Alice" !

I am glad to hear that you had only minor injuries. All this time, I always thought of safety glass on the front of a TV set as a "yeah right, do you really think the picture tube would just blow up?" overkill thing. Obviously, it is not.

The Early Television Museum has a couple of 24-inch CRTs available, 24ATP4 and 24AUP4; maybe you can find out if either one would work in your set. Send them a message to [email protected] or call 614-771-0510 if you find out one of those two could work.

And here I have hauled around loose pix. tubes of various sizes in my vehicles for decades...no problems... (except for one time when a hand
cart fell over onto a tube in the CC van I had, about 11 years ago...when i worked for them..but it was considered junk anyway..it just killed the neck...no "blast".)

Of course...all it takes is ONE time..

Decades ago, a couple of friends showed up at my house, driving a Suburban-type vehicle with the entire area behind the front seats filled with loose CRTs, and not just in a single layer either. I was nervous just standing next to that vehicle with its door open.

That happened to our 1987 Dodge. I was wondering why the backlight looked so cloudy until I got close to it. Very windy day. Didn't hear a pop of any kind though.
I second this.

I MAY have a 24AYP4 tube in an old halolight set I have...IIRC it DID check pretty good on my CR-70, but the SET is in rough shape itself.

Lol!

IIRC I hear that mice can't fart or burp. A friend of mine says natural mouse poisoning is simply to leave a shallow dish of soda out that they can easily drink from...The gas they get from it will kill them since they can't get rid of the pressure from it.

I have a Packard Bell 24STi-something with a good safety glass and 24DP4 CRT which I'll be parting out. The 24DP4 is 2 inches longer than your 24AEP4 but does use a 90 degree deflection angle, so might be a possible sub if you're not able to find the other tube.

Dang, that's interesting.

So as much as mice like cheese, they can't cut it. Too bad.

Okay..... Would you believe a mouse with a hammer impersonating a gremlin??? :scratch2:

SR