My crosley had the flyback catch on fire and destroy the entire set. Could something else have caused this fire, or is this solely a flyback issue? I did run this set about 200 hours and I figured it was free of flaws. I am asking so I can make sure this does not happen again. It has been a long standing dream of mine to have a tube tv. My crosley was it, now on my bench is a very old General electric set and I do not want another fire.Experts, please help!Thank you.

Put the set in a well ventillated place and wait a few days. It may just be a bad fly. How bad was the damage? If you could post pics, that would help. That Crosley may not be a total loss. Flyback fires were not uncommon. Based on your post, I think all you may need to do is replace the fly and clean the set up. I'm sure one of us can tell you for sure either way.

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My crosley had the flyback catch on fire and destroy the entire set. Could something else have caused this fire, or is this solely a flyback issue? I did run this set about 200 hours and I figured it was free of flaws. I am asking so I can make sure this does not happen again. It has been a long standing dream of mine to have a tube tv. My crosley was it, now on my bench is a very old General electric set and I do not want another fire.Experts, please help!Thank you.

Yep ,One other reason for enclosing them in a steel can,besides arc potential.

Flybacks can get hot enough to burn if the HOT cathode current is running above recommended rating.

Were you watching the set at the time? I can't imagine a flyback transformer suddenly catching flame without getting hot enough to stink to high heaven just before that. And to say nothing about other symptoms...

It's kinda funny to me that they would use WAX and PAPER in a component that has the potential to arc and catch fire. They should have went with something less combustable and never allowed flybacks made with wax and paper.

Who knows how many fires might have been started by one of those flybacks...

It's kinda funny to me that they would use WAX and PAPER in a component that has the potential to arc and catch fire.

Actually, both of those materials are excellent insulators. And, remember, sixty years ago, modern synthetic epoxy resins did not exist.

Flybacks can catch fire, this is true. But, aside from making a lot of nasty smelling smoke, they shouldn't cause much else to catch fire. The chassis is made from metal. And I seriously doubt that a burning flyback would be able to make a large enough (or hot enough) flame to be able to catch the inside of the cabinet on fire.

A larger problem with the old wax and paper components (flybacks, capacitors), isn't so much that they could theoretically catch fire, but that they have a tendancy to be affected my moisture. The wax/paper combination is OK at sealing out moisture, but not as good as, say, plastic. The moisture gets into the component, corrodes/breaks down the dielectric properties of the materials, and the component fails.

Wax also melts fairly easily. So, if the flyback gets too hot (caused perhaps by a HO section drawing too much current), the insulating wax melts away, then a partial short forms - then you get an arc, and burning.

-Ian

It's kinda funny to me that they would use WAX and PAPER in a component that has the potential to arc and catch fire. They should have went with something less combustable and never allowed flybacks made with wax and paper.

Who knows how many fires might have been started by one of those flybacks...

I've seen many of them arc, and not catch fire. Fire can occur if the flyback becomes boiling hot.

But with everything properly adjusted a typical flyback shouldn't get hot enough to melt the wax--never mind vaporise, which is what would have to happen in order for it to take flame.

And with all shielding in place the chances of flame spreading elsewhere are slim.

Actually, both of those materials are excellent insulators. And, remember, sixty years ago, modern synthetic epoxy resins did not exist.



I am well aware of that.

However: metal existed, glass existed, ceramic existed, etc. Maybe even bakelite could have been used.

If there is shielding to prevent a burning flyback from destroying the TV, that's fine I guess, but the poster of this topic indicated that his TV was destroyed.

I am well aware of that.

However: metal existed, glass existed, ceramic existed, etc. Maybe even bakelite could have been used.

If there is shielding to prevent a burning flyback from destroying the TV, that's fine I guess, but the poster of this topic indicated that his TV was destroyed.

The reason why flyback transformers were all gooped up with wax was as much an acoustic consideration as much as a high voltage insulator. Without the wax to deaden everything and keep the windings from moving around the coil would've sung at that infamous high pitch of the horizontal sweep until every dog in the neighborhood would go berzerk. As it was they'd sing loudly enough.

For a flyback to burst into flame there must have been something very wrong with the sweep circuitry in that set.

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The flyback was a nos replacement. I did notice that the wax was split. I had the set on and was watching it. I remember now that I did have to adjust the (magnet thing) On the pic tube neck to fill up the screen which after all this time running it seemed odd. I did a couple of things and went back to watch the tv 10 minutes later and it was on fire. The fire followed wiring and took out the Horizon. line.,width, freq, and another coil. It may be possible to buy all these coils and another flyback but I will have a very expensive set with a small book price. That is why I called it destroyed, maybe out of frustration, Doug

I've told myself to make it a habit to never leave a tube set unattended. BUT I know I get quite overconfidant and will leave it on when I use the rest room, or get a bit to eat. This story will make me think twice about leaving them on unattended for even a short time.

Glad you caught the set before it did something real serious, as in your residence going up in flames. I wish you the best of luck. Try Moyers Electronics to get another flyback, controls and coils. http://www.moyerelectronics.com/

As for the price. If you plan to keep the TV then it is worth it to buy parts for it. It makes you happy using it.

Best regards,
Matt Davala

My crosley had the flyback catch on fire and destroy the entire set. Could something else have caused this fire, or is this solely a flyback issue? I did run this set about 200 hours and I figured it was free of flaws. I am asking so I can make sure this does not happen again. It has been a long standing dream of mine to have a tube tv. My crosley was it, now on my bench is a very old General electric set and I do not want another fire.Experts, please help!Thank you.


Hay man I am sorry your set caught fire. This sort of thing can scare the crap outta ya. When you fix the GE set, Connect a ma meter to the cathode of the horz output tube and keep an eye on it for a few weeks. Also turn down the line voltage to 115vac. A 1950's black and white set should work fine at that line voltage and put less stress on the power transformer and the flyback.
Ed

Maybe a bucking transformer maybe in order to drop the ac line a bit. It's simple and cheap. I've often thought about placing a small computer type fan to cool the HV cage. Most have the horz output,damper, and hv rectifer inside. Can get kind'a warm in there.
Terry

Would an outfit like Moyer still have a Crosley fly? Wow, they musta bought a lot of NOS?

The wax coating is peeling off of the flyback on my Zenith bugeye. The fly doesn't get very hot, so I'm thinking that this may have occurred when the set was being played in the antique mall, for hours on end, without being recapped. Should I coat the fly in silicone or some other insulator?

The wax coating is peeling off of the flyback on my Zenith bugeye. The fly doesn't get very hot, so I'm thinking that this may have occurred when the set was being played in the antique mall, for hours on end, without being recapped. Should I coat the fly in silicone or some other insulator?

I use silicone rubber that you can find at radio shack. Discharge the crt just to be safe and clean the dust and dirt off the flyback before you apply it. Silicone rubber has a nasty smell when you first put it on but after it cures it will go away.
Ed

I use silicone rubber that you can find at radio shack. Discharge the crt just to be safe and clean the dust and dirt off the flyback before you apply it. Silicone rubber has a nasty smell when you first put it on but after it cures it will go away.
Ed

Good tip! :thmbsp: I've used rubber cement on one or two in the dim dark past, and have also used "corona dope" but the hazard with either is that it needs several days of curing time before the set can be operated. Otherwise the flyback will burst into flames.

If the smell of the silicon rubber is offensive one might try the sealant made for repairing leaky fish tanks. Such can be had at a pet supply store in the aquarium department. It is far less malodorous.

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Sorry to hear about this... It isn't rare at all. In fact, house fires from malfunctioning TV sets were quite common in the 50s & 60s. I'm glad it stopped with the TV, and from what you say, I bet it's fixable. As long as it didn't get the cabinet involved I guess.

I've had a total-loss house fire, so I'm extra-careful with anything like this. I never leave the room for more than a minute or so, when I'm watching an old set. Or a newer set for that matter. On another note, it isn't just old TVs that shouldn't be left on & unattended... I know two people who had late-model cars in their garages, which burst into flames and burned the garages down due to being started for warm-up in the morning and left for a few minutes while the owners went back in the house to get last-minute things. (one a newer '80s Cadillac at the time), and the other an '02 or '03 Jaguar (glorified Ford Crown Victoria). Neither of those car-caused fires seemed to surprise the fire dept or insurance companies.

Charles

One of the biggest fires our county has ever seen took place back in the 80s. The main shop of a major trucking company burned, eventually traced to a short in a truck that was parked inside overnight.

Your best bet for recoating flyback tranny's would be sensor safe RTV silicone you can get at many auto parts stores,It does not use any acid that can possibly attack the insulation on the copper windings.Before you recoat the fly you should make sure you run the set for a few hours to get any moisture out of the fly so you arent simply sealing in moisture which could cause corrosion problems down the road.Also as for the fire issue maybe you could post a pic of the damage???You may want to inspect the yoke,for damage also as if the horizontal coils shorted then they can cause the fly to smoke.Also older flys were constructed with paper in between each layer of windings for the puropse of insulation and sealed with wax to keep moisture out.Unfortunately when the laquer insultion on the copper wire breaks down due to age or overheating becuase of poor ventilation or other external malfuntions arcing occurs causing heat and smoke and yes sometimes fire if the windings dont open.As a technician that works on modern sets flyback fires are rare but still have happened and in one instance in an older rca proj. set a fly actually detonated very violently and I also have seen where the epoxy breaks down and the fly arcs the the output transistor which is usually located close to the fly in modern sets which usually melts the case.