Perry yes you are right 9540 sorry . The fets are 100% but across the resistor of the 9540s gate they mesure 3.56 volts. On one output driver board I have two transistors that are shorted (1023) cross pin 1-3 0 volts ? Other board same transistors have .650 volts on them .
If you have ±63v rails, the transistors should be 640s and 9640s. Check the originals to see what they were.
You can't use a 9540 in place of a 9640 if the rail-rail voltage is greater than 100v. You have at least 126v.
Perry I have 2 640s and 3 9640s from the amp originals fets that were ok , in the amp right now for testing.
Yes I am sorry on the LM361 aka B52 outputs 9 and 11 have ±1.2v . typing between installs haha .
There are two sets of outputs. On the center legs of the output transistors, do you have 0v on one side and -63v on the other side of the amp?
Perry when I do this do I need for the output fets to be in both sides ? Cause right now I only have them on one side 2 640s and 3 9640s for testing , the other side is empty .
Ok Perry heres what I got of all the out put fets
* other side of resistor -37.4 it jumped to -36.4 on the gate for alil bit and back to -16.42 and it stays there turn off power turn power on still at -16.42
left side 9640
1. -16.42*
2.-37.6
3.-37.6
640
1. 37.5
2. -37.6
3. 37.7
right side
9640
1. 37.7
2. -37.6
3. 37.7
640
1. -37.6
2. -37.6
3. -37.6
Also I think I burned out the NJM 13600 all the ic on the output side have +/- 2 volts . On your repair disk is there a page with the NJM 13600 inputs outputs ? Thank you Perry .
* other side of resistor -37.4 it jumped to -36.4 on the gate for alil bit and back to -16.42 and it stays there turn off power turn power on still at -16.42
left side 9640
1. -16.42*
2.-37.6
3.-37.6
640
1. 37.5
2. -37.6
3. 37.7
right side
9640
1. 37.7
2. -37.6
3. 37.7
640
1. -37.6
2. -37.6
3. -37.6
Also I think I burned out the NJM 13600 all the ic on the output side have +/- 2 volts . On your repair disk is there a page with the NJM 13600 inputs outputs ? Thank you Perry .
I don't think I have any voltages for that IC. What do you mean you have ±2v on the output side?
Do you see signal on the top row of pins or on the bottom row of pins?
Do you get the same DC voltage on ALL of the 9640s on the left side? Check the pads if there are empty 9640 locations.
Do you see signal on the top row of pins or on the bottom row of pins?
Do you get the same DC voltage on ALL of the 9640s on the left side? Check the pads if there are empty 9640 locations.
On the voltage regulators for the output ic's ±2v. All the ic's have this voltage and R52 and the other resistor get hot again, cause I think I burned 13600 need to check it out. I smelled smoke and on the sides of this ic it has alil bit of powder from the ic .
No signal on any pins . but then again low voltage ±2v.
Yes on the left side it has same voltage , left side has no fets . right side has fet in place .
No signal on any pins . but then again low voltage ±2v.
Yes on the left side it has same voltage , left side has no fets . right side has fet in place .
Remove the 13600 if you think you damaged it. Does the voltage go back to what you'd expect on the regulators?
On the side of the amp with the 9640s that have -16v on the gates, do ALL of the gate pads/legs of the 9640s have -16v or do some have -37v?
What is the total number of 640s and 9640s on one side of the amp?
On the side of the amp with the 9640s that have -16v on the gates, do ALL of the gate pads/legs of the 9640s have -16v or do some have -37v?
What is the total number of 640s and 9640s on one side of the amp?
Will do tonight .
Yes the left side gates of the 9640s have -16.42 this side has no fets in place.
(3) 640's and (4) 9640's on per side.
Yes the left side gates of the 9640s have -16.42 this side has no fets in place.
(3) 640's and (4) 9640's on per side.
I think you have bad drivers or an open resistor (low value, 1-4.7 ohms) on the driver board. If you pull all of the outputs from the side with -16v on the gates, what do you have on the outputs on the other side of the amp?
You are right the gates resistor should be 70ohms and they sit at 30ohms but I need to unsolder one side and mesure first . On the left side there are no outputs fets , only on the right side 2 640s and 3 9640s installed.
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