Phase Linear 4000 Series two.

VSAT88 said:
I sure ain't complaining, glad there is no compound to clean off. Here are a few naked pics. I did not have a large banana so an old tops rolling machine had to do.

View attachment 66475View attachment 66476View attachment 66477View attachment 66478
Click to expand...
What a Deal! looks like a Q-comp. have you bussed out the backplane for shorted out transistors yet?

This is a different way that I do it. For testing and working on it.
I never take the bottom cover off and I don't flip the PL on its fins
I than I flip the display over laying it on top of the fins w a mat or mouse pad under it and than later I flip the control board to the bottom w the cover not removed onto another mat (You have to watch for the transistor from bending from the weight of the board) I also have a Lazy Susan Rotating Turntable under the PL than I can spin it around and to hook up load resistors, Generator and scope and I also can spin it to work on the back of it.
 
I kinda half ass looked it over with a meter and yes, a few OPT must be bad. Of course on the same side someone did a "repair job" and did not match all of the OPT. This may be the reason I have Sil-pads on all the OPT. Seems to me if they we going to go to all that trouble they would have used all new on at least that one channel.

20220610_182033.jpg
 
VSAT88 said:
I kinda half ass looked it over with a meter and yes, a few OPT must be bad. Of course on the same side someone did a "repair job" and did not match all of the OPT. This may be the reason I have Sil-pads on all the OPT. Seems to me if they we going to go to all that trouble they would have used all new on at least that one channel.

View attachment 66493
Click to expand...
I would from the manual "finding shorted transistor test" to see if their are any bad banks , The RCA hardly ever fail. they all might be good?
I don't like to take all of them out all at the same time. I find that it makes to easier to put them in and out when they are lined up.
 
Thank you Don. I have not read that complete manual yet. It was kind of hard for me to believe that anyone had been in it really. I could not understand why two OPT were different from all the rest and it came that way factory. Also could not understand why someone would have changed two and put Sil pads under all the rest. Now I know what one actually happened. It came from the factory that way.
 
I done got old enough that don't learn something new every day but I still learn something new every so often. I like knowing this one.
 
Date codes on those big caps too...in fact there is a manufaturers number in the code if the builder isn't printed on them...used to have a list around here someplace....
 
Yep, part of not the. I would assume too much current draw when the OPT shit the bed ? I don't recall seeing a emitter resistor do that before.
 
You must log in or register to reply here.
Back
Top