Watched that & communicated with him. It was a broken U-bolt on the FBT.
Holds the ferrite core halves together. Without it the resonant freq goes off
& you would see garbage on the drain of the SG. Normal wave form would be one big clean spike. Normal transistors in Hoz out can also instant destruct &
sometimes cause a chain reaction BUT most the time there are easy ways to
fix them. The real bad ones were the 17" sets with the controls along the bottom. At the time they were the BEST you could get. The first runs had TWO SG-613's one for hoz out & one in the power supply. A nightmare.
So to Shangos set. Cost was the big thing In the day SG-613 = $25,
OEM damper $8, OEM 2SC867 $12. Add a C-note for labor. A few weeks
later the customer hears a click & everything is blown again. You
have to eat the SG613 as Sony WILL NOT warranty them ( along with
video heads, some clocks & other things).
Nuff fer now, always a pleasure Alan.
LFOD !
Quote:
Originally Posted by AlanInSitges
A while back Shango had one of these that kept eating all of the semiconductors in the HO section. After lots of back and forth he tracked it down to a broken - what do you call it, wire? bracket? clamp? - through the flyback core. I can't remember the whole reason this caused it to happen; it was a really complicated circuit.
|