Recent content by loweran

Nothing too out of the ordinary. Most of the board are on the bottom and easily accessed. Note that my PS board had a 47uf 50v cap at C14 and not the 220uf 10v that the schematics and parts lists all have. I think that is common. Otherwise the available parts lists are spot on. There is one list...

All done. Ain't she beautiful!

Dragon has been tickled and it is on the meter now getting dialed in.

OK, I think I solved it. It was Q13. I realized after looking at the schematic that these pairs are joined at the B+-. I reused some of the micas and that may have been my mistake. Next up is to put it back together and tickle the dragon.

Update: Pulled Q14 and Q16 again. Pulled the sockets from the heat sink. There is still continuity of the red lead with the heat sink. There is also continuity at pin 29 on the board. Not sure where to look from here.

Update: I removed the screws to Q14 and Q16, pulled the socket from the transistor leaving it in place on the heat sink and they are now isolated from the heat sink, however the red lead on the socket is not. Edit: looking at the board diagram, that red lead connects the collectors and is on...

They looked dry so I went ahead and pulled them, cleaned, re-greased, and re-installed them. However I am now getting continuity on Q13 - Q16. Are these supposed to be grounded to the chassis? I may pull them inspect and re-install to see what the story is. Here are the after pics:

I will give it a look. The stuff on the PS transistors was still good. I might pull one and see what I have.

Here is another question I probably already know the answer to. Is it always necessary to pull, clean and re-grease the output transistors? The grease on the transistors on the power supply board seemed fine. I suppose I should do them for peace of mind. I have some receivers I have done, and...

On the last board, the amp board. For Q9, 10 I realized I only have one KSC2073. For Q11, 12, Mouser is out of stock on the KSA940s. Could I replace these with 863-MJE15032G and 863-MJE15033G? Edit: looks like I was mistaken, they do have them in stock.

There were a boat load of those blue drop caps

EQ Board:

Flat amp and tone boar

Power supply and Protection Boards:

Cleaned the switches and phone1 sounds normal. However, there is still AUX bleedthrough.