Try reconnecting the wires to see if you still have both positive and negative 33v.
If so, try reinstalling in one of the modules to see if it will produce audio.
If so, try reinstalling in one of the modules to see if it will produce audio.
At this point, I don't think it matters. I believe that the bridge rectifiers are made for 50/60Hz.
You could compare the heating of the two bridge rectifiers by reconnecting them with wires so that you can get access to the body of the rectifiers to see if they are overheating with a light load (lamp across the positive AND negative output, no ground).
You can do that either before or after checking for audio.
Using the MUR rectifiers will be, in my opinion, a better option but will also be more costly because you have to source screws, shoulder washers, insulators...
Does the other amp also have open space adjacent to the PS transistors?
You could compare the heating of the two bridge rectifiers by reconnecting them with wires so that you can get access to the body of the rectifiers to see if they are overheating with a light load (lamp across the positive AND negative output, no ground).
You can do that either before or after checking for audio.
Using the MUR rectifiers will be, in my opinion, a better option but will also be more costly because you have to source screws, shoulder washers, insulators...
Does the other amp also have open space adjacent to the PS transistors?
Ok, I will leave the little diodes in for now. tested and neg side still has voltage at 32v neg. Pos side has 1.5v pos and drops out and comes back
light still connected to orange arrowland on one side and other side to pos rail, it does not light up. I also tried this on the neg side and it did not light up there either.
output from transformer has no waveform. input, no waveform. checked both PS transistors and no waveform there either. Settings not changed on CRT scope
also, to respond to your other question, the other amp has all four spots occupied for the PS transistors.
I think you turned more than one page.
You can't have 33v without the collector waveform. Then the secondary. What happened there.
You can't have 33v without the collector waveform. Then the secondary. What happened there.
ok, not sure here. Seems the CRT scope may be having issues. but I double checked it with the fluke 97. So, with the CRT scope and the fluke 97 the crt scope didnt really read anything. the fluke showed a really noisy signal with no solid square wave.
I checked this multiple times including verifying the amp had power to it. After concluding that whatever I had done created this anomaly, I desoldered the pos and neg rail wires from teh audio board. I then verified I had pos and neg voltage. Both were present, BUT no sinewave.
So, here is what I know by triple checking my tests.
if pos rail is connected to audio board, no sinewave and no pos rail voltage.
disconnect pos rail from audio board with amp still on, no sinewave, no pos rail voltage.
remove amp power, depress button for 2 channel vs bridge mode (cycling relay to drain caps) and I get both sides of rail voltage back and both sinewaves.
very strange.
I checked this multiple times including verifying the amp had power to it. After concluding that whatever I had done created this anomaly, I desoldered the pos and neg rail wires from teh audio board. I then verified I had pos and neg voltage. Both were present, BUT no sinewave.
So, here is what I know by triple checking my tests.
if pos rail is connected to audio board, no sinewave and no pos rail voltage.
disconnect pos rail from audio board with amp still on, no sinewave, no pos rail voltage.
remove amp power, depress button for 2 channel vs bridge mode (cycling relay to drain caps) and I get both sides of rail voltage back and both sinewaves.
very strange.
You MUST have a square wave on the collectors of the PS transistors and MUST be able to confirm this at all times. Until you can do this EVERY time, we're wasting our time.
Yup, totally agree. No sense in wasting time. I did some other tests with the CRT scope and have concluded it is having issues. The Fluke 97 though seems to be reporting facts consistently.
So as it is right now, Im getting a solid square wave on both collectors of the PS transistors and both pos and neg rail voltage with those wires, respectively, desoldered from the audio board.
So as it is right now, Im getting a solid square wave on both collectors of the PS transistors and both pos and neg rail voltage with those wires, respectively, desoldered from the audio board.
The CRT scope is a single channel, so cant do that. Probe is new. Swapped probe from CRT scope to Fluke and it works fine, so I guess from here out we only have the Fluke to do with.
From here on, you have to confirm that you have all of the following whenever the amp is on.
24v square wave on collectors of PS transistors
±33v square wave on secondary windings that feed the AC terminals of the rectifiers
±33v DC on the capacitors and the wires feeding the audio board
If you have near 0v on one of the rectifier diodes/caps, you must confirm that you still have all of the above.
If one of the caps has essentially 0v but you have all of the above, insert the lamp in place of the wire that's losing voltage to see if there is current flowing through it. It will likely light up slightly, if nothing else, you should read voltage across it (how much?).
24v square wave on collectors of PS transistors
±33v square wave on secondary windings that feed the AC terminals of the rectifiers
±33v DC on the capacitors and the wires feeding the audio board
If you have near 0v on one of the rectifier diodes/caps, you must confirm that you still have all of the above.
If one of the caps has essentially 0v but you have all of the above, insert the lamp in place of the wire that's losing voltage to see if there is current flowing through it. It will likely light up slightly, if nothing else, you should read voltage across it (how much?).