matsushita vert collapse

corky

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i have a matsuposhita in a millipede that is currently experiencing vertical collapse. i already did a cap kit and reflowed all ics and any questionable solder joints, but still no luck. whats the next step from here?
 
change out the vertical output transistors. they are the small black box with three legs transistors mounted to the metal frame in the middle. if that doesn't work I have a good working chassis for 75.00 shipped or you can ship me your's too.
 
best of luck, but sadly heres my advice:

kill-it-with-fire.jpg
 
change out the vertical output transistors. they are the small black box with three legs transistors mounted to the metal frame in the middle. if that doesn't work I have a good working chassis for 75.00 shipped or you can ship me your's too.

changed both vertical output transistors today, still no change. any other suggesetions?
 
pulled and checked both vert pots; theyre working fine. reflowed EVERYTHING in the vert circuit. hooked it up, still the same effin problem. any other suggestions for a quick fix before i bust out the schematic and start checking individual components?
 
shameless bump

(almost positive) its not cold solder joints, the vertical output transistors, the vertical pots, or the capacitors. im assuming its probably a bad component in the vertical circuit somewhere. is there anywhere else on the board that could cause vertical collapse? should i check certain components on the board before others? im also guessing this is not a tube issue? any help/advice is greatly appreciated. im quickly reaching the limits of my technical prowess and its a little overwhelming. thanks
 
ok, i was able to plug the chassis into another tube and it fires up with full picture. this leads me to believe that my problem is not with the chassis, but with the tube/yoke. how do i go about testing the yoke to see if its bad?
 
Yoke

Use an ohm meter on each of the 2 yoke windings. compare it to the working one. You will find the verticle windings are probably open.


ok, i was able to plug the chassis into another tube and it fires up with full picture. this leads me to believe that my problem is not with the chassis, but with the tube/yoke. how do i go about testing the yoke to see if its bad?
 
I hate to be an ambulance chaser here, but... If you've got a good TM-202 chassis, I'm in the market.
 
ok, i was able to plug the chassis into another tube and it fires up with full picture. this leads me to believe that my problem is not with the chassis, but with the tube/yoke. how do i go about testing the yoke to see if its bad?

well, i didnt even need to test the yoke. i pulled the monitor to do a tube swap, and gave it another once over just to make sure i didnt miss anything. sure enough, a little rodent friend that was living in the machine at some point chewed through one of the yoke wires. soldered that bad boy back together and it fired right up (and it looks beautiful).

gotta love spending a month troubleshooting the chassis when it was a 30 second fix on the yoke...

picard-facepalm.jpg
 
LMAO! Sorry dude..but I've been there...amazing how sometimes you can take a few days off go back and see something you wonder how you missed all those other times...:D
 
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