sanyo 20EZV- getting closer, but only 89 volts at Q901

pinnut

Active member
Joined
Aug 3, 2010
Messages
1,084
Reaction score
20
Location
New York
sanyo 20EZV- getting closer, but only 89 volts at Q901

had a dead 20ezv. recapped, no help. no neck glow, b+ stuck at 91 . i replaced the flyback and B+adj pot. now have neck glow, and a very dim raster image, but B+ stuck at 91.5 thru out the range of the B+ pot . anode voltage is steady at 20K . i do have an ic601, but didnt install it yet, wanted to get opinions first.

thanks
 
Last edited:
IC601 didnt help. i only have 88v at the Q901. should have checked that first. im running the iso transformer at 110v thru a variac. what could cause the low voltage at q901?

thanks
 
with the HOT disconnected, i get 130v DC at the 300ma DC fuse. i get 129 at the heavy red wire to the hot. adjusting B+ pot( new) doesnt change the above.
 
Did you replace the small electrolytic capacitors (especially in this case in the B+ section) ?

I ran into one where I used an older cap kit that did not have a few of the smaller caps... and it turned out a 1uF electrolytic in the B+ section caused me a couple of hours of grief.
 
i replaced all the caps, looked at the board with a fine tooth comb, reflowed tons of joints. no matter what i do, i cant get B+ over 89 V. i have 128 at the minifuse, and 127 at the collector of the q901 current limiter. emitter and base are both 88 V . Q901 is new, as is the ic601 regulator. im starting to think i wont get out from under this.
 
can i remove the HOT and bench test it to try to find the issue? does it need a load , like a 100watt bulb? if so, where would i load it from?

thanks
 
i wish. b pot is new, i think i mentioned that in my first post. this thing really is a bear
 
Back
Top Bottom