Originally Posted by bomelia
I have yet to open the back of the set, and I have no idea which bourd is the D Board. Help? Schematics? Or does it have a big fat D emblazoned on it!?
Also, was it easier to remove the board before working on it?
Actually, it does have a big fat D on it
But it may be hard to see, its in the middle of the board, I believe. The D-board has a three or four inch black and gray component (flyback transformer) on it with a stiff/thick red wire that runs up to the tube anode and a couple of wires running to the tube neck boards. Looking from the rear, the D-board is on the left. IC8002 and IC6501 (both MCZ3001) are located between the flyback and the two largest capacitors (metal cylinders) on the board.
According to the service manual, there is a service position, wherein the bottom section, D-board + the rest, can be rotated up so that the bottom of the boards are accessable. This is done by lifting levers on the right and left of the chassis bracket. Your other option is to remove the board, however the connections on the flyback are very tricky and can be broken if not detached correctly.
Your EE friend must have given you a few tips already, but I'll add some. Make note of the orientation of the ICs and make sure the sockets and new ICs are oriented the same. Most ICs and sockets have some type of dot, indentation or mark that denotes the pin 1 end of the chip. According to the schematic, pin 1 is oriented to the closest edge of the board, or left side of the board when looking from the rear of the set for both MCZ3001 chips.
Be careful to not damage the traces on the board. Desoldering braid works very well in clearing solder from the holes. I agree with RobertF that installing sockets is a good idea.