MK3 w K7197 Flyback getting hot; melting

if R101 goes out of spec it creates havoc for the B+. you should be able to measure it in circuit and find 6.8k ohm. if it doesn't reach this number like immediately, chances are R101 is bad. it doesn't matter how well it tests out of circuit, it's intended to operate in a circuit. I've discussed this with Buffett at length and I'm guessing he's never seen it or something. :p

R89 is another suspect, I think that's a ceramic. lastly, you can entertain changing out C38.

I've got a million K7000s at work doing this, I just can't fix them right now.

I did a few K7000s at Arcadecup with the same problem and replacing those parts fixed it.

i rarely see R101 bad.
i have only replaced it in the past once or twice.

now i do see the pads and trace on it bad all the time.
once i get that all fixed up, the resister read what it is supposed to.

must be a state thing or something.

Peace
Buffett
 
I found R89 and C38 on the map, but can't find R101. I found it on a Control Board, diagram, but this chassis does not have a remote control board.

Where is R101?
 
Buffett, is that from the k7000 manual? It looks more detailed than what's in my manual.
 
we saw those resistors under a FLIR gun.

they get hot. why do you think the solder pads in that cluster of resistors die so frequently?
 
What do you know.. a replacement flyback.. is the tube and yoke original?
As for transistors being good or bad and do not replace them if they are working I totally agree. Cant hurt to apply fresh compound and a heat transfer pad if the original looks aged.
On the argumentative side you will not know if a transistor is truly damaged until you crack it open and view under a microscope to see if static / excessive current craters are microscopically imprinted on the silicone. ESD / current damage.
 
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Yup, we did. Probably the reason why zenith went with a 5watt version vs 3 and why wells put a 5w in the very last runs of k7000's

we saw those resistors under a FLIR gun.

they get hot. why do you think the solder pads in that cluster of resistors die so frequently?
 
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