Sanyo 20EZ HV shutdown...

RetroHacker

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OK, I'm really puzzled by this one. Working on a Sanyo, it was in horrible shape when I got it - bad flyback, HOT, filthy, etc. I fully recapped it, replaced the flyback with one of Chad's replacements, replaced the HOT, new fuse, new 180ohm 20W resistor, etc. Finally got it to power up and display a white screen, trying to adjust the B+ I was having problems that I had attributed to the really flakey old pot.

Well, I just replaced the pot, and I'm still having problems. Basically, the monitor stays on with a B+ of 95v or so. But as I adjust the B+, the highest I can get it to go is around 98.5 volts - at which point the monitor shuts down and the voltage shoots up to 134v. The pot is good, I can measure it's resistance smoothly through it's travel.

And yes, I am powering this through a Nintendo 100v isolation transformer (albeit on my bench, but still, it's a real Nintendo isolation transformer).

-Ian
 
Sorry to hijack this thread but, I am having a similar problem with my Sanyo EZV. New HOT, Flyback, and a Delux cap kit. It B+ at 134V and adjusting pot doesn't move the B+ voltage at all. I just replaced IC 601, it didn't fix my issue. What sould I look for next?
 
+1 on a similar problem except my B+ is too low (88v) and adjusting the pot does nothing. I've been watching this thread to see what recommendations people come up with. I haven't replaced the pot or IC601 yet. Is that the logical progression?

- Mike
 
Well, I just ordered the part from Bob Roberts, but if it doesn't fix it, I'm not sure what to do next... Never had a Sanyo kick my butt like this one has.

-Ian
 
Yeah mine was at 88v, then after about 15sec it shot up to 134v, and that is where it has remained, I replaced the filter cap, in addition to IC601, and the B+ pot. Still nothing!! I have high voltage and I get the static charge crackle on the front of the tube, but I have no neck glow. Does yours have neck glow?
 
My monitor works and looks really good. It just has a wave that goes across it and the horizontal image is only 3/4 of the screen Adjusting the horizontal width coil does nothing. The B+ stays at 88v no matter how long it is on. I am hoping that when I get the B+ adjusted right it will resolve the width and wave issues. Fingers crossed and here's to hoping that Radio Shack has a 5k pot.

- Mike
 
Hmmm, sounds like a different issue than what I'm dealing with.
Have you tried putting an ohm meter across the B+ pot and adjusting it with the monitor off? If your pot is good you should be able to watch the resistance vary from near 0 up to 5K? If Junk Shack doesn't have them, Bob Roberts carries that pot for a buck. Add in his 7$ shipping and its an 8$ pot! Ouch!
 
Sorry to hijack this thread but, I am having a similar problem with my Sanyo EZV. New HOT, Flyback, and a Delux cap kit. It B+ at 134V and adjusting pot doesn't move the B+ voltage at all. I just replaced IC 601, it didn't fix my issue. What sould I look for next?

+1 on a similar problem except my B+ is too low (88v) and adjusting the pot does nothing. I've been watching this thread to see what recommendations people come up with. I haven't replaced the pot or IC601 yet. Is that the logical progression?

- Mike

Could be a bad Q901 current limiter transistor too.
 
+1 on a similar problem except my B+ is too low (88v) and adjusting the pot does nothing. I've been watching this thread to see what recommendations people come up with. I haven't replaced the pot or IC601 yet. Is that the logical progression?

- Mike

A bad filter cap can drag down the B+.

Edward
 
Well, I just ordered the part from Bob Roberts, but if it doesn't fix it, I'm not sure what to do next... Never had a Sanyo kick my butt like this one has.

-Ian

grr so you are the one who got his last one and thus making me wait another week for his new shipment :)

I hope it works out for both of us. same boat as you boys
 
My monitor works and looks really good. It just has a wave that goes across it and the horizontal image is only 3/4 of the screen Adjusting the horizontal width coil does nothing. The B+ stays at 88v no matter how long it is on. I am hoping that when I get the B+ adjusted right it will resolve the width and wave issues. Fingers crossed and here's to hoping that Radio Shack has a 5k pot.

- Mike

This one sounds like a bad filter cap.
 
Hey Dokert, can't speak for the other guys, but mine also has a brand new Q901 25D1090 Ccurrent limiter too?!? Any other reasons for a constant 134v on the B+???
 
Dokert,
Unplugged L901, B+ was at 90v, was able to adjust it up to about 105V, then voltage shot up rapidly to 134v, remained there, B+ pot no longer adjusted the voltage. Also no neck glow.....Thoughts?
 
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