Update Hitachi blowing HOTS
 

Jun 27, 11:13 am
Hitachi model #50EX10B - Yes, I posted months ago about this same set.
Sorry, but I still need help. Keeps blowing horizontal outputs. Flyback

primary checked good. Seems like it blows right when the high voltage
is starting to come up. B+ voltage dead on accurate. I have checked
several caps for leakage and ESR, just about every diode, and can't
find a faulty component. Have removed the CRT boards in case of bad
tube, but don't get high voltage. Maybe protective shutdown with no
load? Anyhow, it blows them when everything is connected. Should I be
looking on the primary side circuit of the flyback, or could this be a
faulty load on one of the secondary's circuits? I am close to bringing
it to a shop and paying for repair or info on what's wrong. Last call
on this one. Thanks group.

Well, I finally found the problem. It turned out that it was a bad CRT
(green). Think the neck had a slight crack in it. Since replacing the
last HOT, I did hear some flashing/buzzing at power up, but wasn't
behind the set, and the HOT blew. Also have replaced the switching
regulator, B+ fuses, etc. I own a 50" Hitachi similiar to above, so I
swapped flybacks and HOTS to see if this was bad. I heard the flashing
and shut the set down. I got behind it this time, powered back up, and
this time saw the flashing in the neck of the green CRT. Pulled the
board and anode, powered set back up and presto....high voltage and the
other tubes fired up. I am going to replace the tube. Thanks alot to
all that have submitted advice on this thing. I sure have gained some
repair experience.