Rare find! A Magnavox Brittany tv!

[Yamamaya42]

I have a 120mm ac fan that I will put in place of the HV cover, it should fit rather well, it will be heard, but blow a good amount of filtered air on the flyback.
This is for sure one of those "What were they thinking?!?" moments for Magnavox, as they knew there was a stress,heat problem and their fis was to mount it on the copper plate.

[Electronic M]

I use fans too on some sets (rare and high use models mostly) if a set uses a power transformer and it doesn't run hot I'll usually use a 12VDC fan and rectify the heaters for 6.3VDC (or if I think I need really strong wind I'll use a double circuit. 6.3V tends to quiet cheap fans and still move enough air to be useful.

Ymmv.

[dtvmcdonald]

I recommend a 4 inch muffin fan, a 240 volt AC model,
run on 117 VAC. Plenty of air for a TV, no noise.

[kf4rca]

And I'd use a ball bearing fan rather than a sleeve fan.

[Yamamaya42]

Originally Posted by kf4rca

And I'd use a ball bearing fan rather than a sleeve fan.

I have one of these, and they are unstoppable
https://www.newegg.com/p/1YF-003V-00...1BDJyY0Bp4jbaH !

[MuzzcoVW]

Originally Posted by Yamamaya42

I have one of these, and they are unstoppable
https://www.newegg.com/p/1YF-003V-00...1BDJyY0Bp4jbaH !

Bookmarked! That looks like a really nice unit. I plan to pick one up to try in one of my Predictas

[Yamamaya42]

Disaster..

the Flyback went up in smoke today. DEAD

I have no choice now but to try the RAM FBT
http://suzaku.live-evil.org/ramfbt.jpg

making this work in the place of this.
http://suzaku.live-evil.org/hvo-5.jpg
As there is no correct replacements.

I can find no real reason for why it burned other than it may have been damaged when it was dropped.
http://suzaku.live-evil.org/maggy-bad.jpg re-using old pic again

looking for missed bad parts again i am not finding any smoking guns, r185/185 are a bit off not bu much they are 20% parts one tests 112 the other 115, i left them in, those can't be the cause, cathode resistors are perfect.
tubes never showed any signs of stress.

I have no idea why point 1-2 burned up 2-3 is fine 4-5-6 is perfect, just 1-2-3 is toasted.
perhaps it did not like being run on 2 tubes?
any ideas?
When i do try this other FBT, i will most likely ignore the pin 4 on it and use pin 7 as if it was #4 , bypass the voltage doubler circuit, as it already puts out 13kv w/o it.

[Yamamaya42]

paperwork
http://suzaku.live-evil.org/0603252258.jpg

[Yamamaya42]

been going over it again and again, can't really see a reason why it fried... the ,25 cap on the cathode of the HOT was replaced before i got it with an orange drop, the 100 ohm is perfect in spec, makes little sense.

[Alex KL-1]

Good or bad, perhaps the flyback failed by it's own.... I watched it several times with various TV's.

[Yamamaya42]

So now I'm stuck with trying a flyback transformer that's alien to the set, ram x032 and sort of a match, OR, trying something really crazy and Frankenstein like...

[Chris K]

Originally Posted by Yamamaya42

So now I'm stuck with trying a flyback transformer that's alien to the set, ram x032 and sort of a match, OR, trying something really crazy and Frankenstein like...

Did you check the list of spares harvested on the ETF website? I actually found an RCA VOT there that was the same part number as the one that failed on me.

[Yamamaya42]

Before I try the RAM-X32 in there, i am going over things again, not finding much.
http://suzaku.live-evil.org/0604252130.jpg

As i said the grid resistors which were 20% were just in spec, r184/185 getting new, cathode resistors tested perfect,, gonna replace all 4 with 1%. the cap on the cathode .25 they almost never go bad, right? gonna replace it anyway and the other one there like it, r199 looks like crap but tests at 9.6k well within 20% for a 10k, but it get replaced too.
Again, no smoking gun for why the FBT blew.

[Yamamaya42]

Mouser is about to ship the parts, as always shipping is almost half the cost, THIS TIME I will rig it only with one horizontal output configuration, the 6BG6 is a 20w tube, more than enough for the 52 degrees of the 16LP4, perhaps the dual mode was too much for the Merit HVO-5, and it had a fit and melted down or something, not sure what the total power in dual mode would be, 30-35w?
The OEM flyback did seem to built a bit more robust, so who knows, when it was working with the HVO-5 it seemed to work really well, till it caught fire!!

However, the the X032 seems very flexable, says will work with one 6BG6, and 13kv out with one 1B3GT.

[Chris K]

OMG I'm so sorry to hear that! Power transformers, yokes, flybacks and tuners are my top dreads for failures. Best of luck with the replacement.