KV-1222RS Trinitron Vertical

[Findm-Keepm]

Originally Posted by Zenith26kc20

No vertical is usually the vertical IC and some capacitors connected to it. The caps cause the IC to run hot and fail. A sure sign caps are bad, once the IC is replaced is a foldover at the top of the screen.
I remember that I had to add to the heat sink to keep the IC alive. Apparently towards the end of that IC's popularity, seconds were being sold. I had the same trouble with Zenith power supply IC's when the sets with all the shorted CRTs came along. The seconds always ran HOT!

With those Sonys, the chip is rarely bad - it's usually 1) the 22uf/50V cap off the yoke return - it's open, and ESR will be >10 ohms or so 2) Solder connections at the chip itself 3) Bad 24V or 28V source feeding the chip 4) the 10uF boost-up cap, also in the vertical area.

With lightning strike sets, the chip will usually short, taking out the 24 or 28V source - replacing the chip fixes that, but you wouldn't have a picture with the chip shorted. Two different versions - the UPC1378 and the UPC1488 - you have the earlier, and the caps are usually the culprit.

OP, have you checked the solder on the chip, and the presence of the 24-28V source feeding the chip?

[targeteye]

Originally Posted by Findm-Keepm

With those Sonys, the chip is rarely bad - it's usually 1) the 22uf/50V cap off the yoke return - it's open, and ESR will be >10 ohms or so 2) Solder connections at the chip itself 3) Bad 24V or 28V source feeding the chip 4) the 10uF boost-up cap, also in the vertical area.

With lightning strike sets, the chip will usually short, taking out the 24 or 28V source - replacing the chip fixes that, but you wouldn't have a picture with the chip shorted. Two different versions - the UPC1378 and the UPC1488 - you have the earlier, and the caps are usually the culprit.

OP, have you checked the solder on the chip, and the presence of the 24-28V source feeding the chip?

Ok so i finally had time to try and do something with this TV. After getting the dust out of it ... the I checked and the IC is not getting any voltage to it. Should be 24V on pin 6 but it reads zero. TP96 also reads zero. I'm trying to wrap my head around this schematic and figure out how the 24Volts is generated but not having much success.

Here is a link to the schematic, Its to big to upload here.

https://drive.google.com/file/d/1bTd...ew?usp=sharing

Steve