[kc8adu]

shhhhh.dont give away everything!
those sets keep me busy!
along with thompson crap

Originally posted by rca2000
If you have, or are going to purchase a sony tv,27"to 36", made from around 1990- now, there is something you should be aware of-- and this MUST be addresed, to prevent a BIG repair bill.

I have worked on many of these, and they are a good set, with a GREAT crt. but, they have one serious weakness.

In the modern Sony tv's, the power supply is a switch-mode type,WITHOUT CURRENT LIMITING. This means, that if there is a short on the main b+ line, the 135 volt source, THAT THE SHORT WILL DESTROY SEVERAL PARTS IN THE POWER SUPPLY, LEADING TO A REPAIR, ON THE AVERAGE OF $200.00, OR MORE.

What the problem ,and weakness in these sets is stems from a habit of developing bad connections on the horizontal driver transformer. At first, this causes intermittent high voltage, and raster, but if allowed to continue, AT ALL, it WILL stress the horizontal output, and kill it. Then, because of the lack of current limiting shutdown features in the power supply, the short WILL BLOW THE TWO SWITCHING TRANSISTORS IN THE SUPPLY, AND A RESISTOR FEEDING THEM, OR ,IN THE NEWER SETS, THE HYBRID IC SWITCHING REGULATOR, CAUSING THE NEED FOR THE REPLACEMENT OF ALL OF THESE ITEMS.

The cure, is to open the set, and solder ALL of the connections on the driver transformer( the small transformer, that feeds the base of the horiz. output), and the connections between the base and the secondary of the driver transformer. DO NOT , REPEAT, NOT USE GENERIC REPLACEMENT PARTS, FOR THE POWER SUPPLY TRANSISTORS, OR THE HORIZ. OUT. THEY WILL NOT LAST!! I know this, from much personal experience!!