Q29 power supply section regulator that is soldered to the board.........
There are only 2 legs on it......the in and out leg.........why is the middle leg missing? Isnt the middle leg the adjustable part of the regulator or the voltage reference?
Shouldnt the middle leg be on this regulator?
There are only 2 legs on it......the in and out leg.........why is the middle leg missing? Isnt the middle leg the adjustable part of the regulator or the voltage reference?
Shouldnt the middle leg be on this regulator?
I am going to post readings of regulators including negative...........
Q14 LM337
pin1: -15.21
pin2: -26.99
pin3: -15.49
Q28 LM337
pin1: -4.69
pin2: -20.00
pin3: -5.96
Q13 LM317
pin1: 14.92
pin2: 16.22
pin3: 26.82
Q27 LM317
pin1: 4.83
pin2: 6.09
pin3: 16.85
Q5 LM317
pin1: 9.69
pin2: 10.95
pin3: 17.00
Q29 LM317
Pin1: 9.15
pin2: cut off and not used
pin3: 17.52
Q28 LM337 and Q27 LM317 are much lower than the rest any thoughts on that?
Q14 LM337
pin1: -15.21
pin2: -26.99
pin3: -15.49
Q28 LM337
pin1: -4.69
pin2: -20.00
pin3: -5.96
Q13 LM317
pin1: 14.92
pin2: 16.22
pin3: 26.82
Q27 LM317
pin1: 4.83
pin2: 6.09
pin3: 16.85
Q5 LM317
pin1: 9.69
pin2: 10.95
pin3: 17.00
Q29 LM317
Pin1: 9.15
pin2: cut off and not used
pin3: 17.52
Q28 LM337 and Q27 LM317 are much lower than the rest any thoughts on that?
Perry read the results of my last post before this one.
I tested the regulators on a working T3001 and got the exact same readings as the unit being repaired. I dont think the regulators are an issue.
I checked the outputs on the scope on the working 3000 and the drains for 8 outputs have a square waveform and the other 8 the gates have a square waveform.
When testing the bad 3000 I can kinda of see the waveform but its pulsing very fast and hard to read.
Something is causing the output side of the board to pulse all of the signals all over the board, I think something from the power supply is perhaps sending a faulty signal to the output board and causing havoc but I am not for sure.
I tested the regulators on a working T3001 and got the exact same readings as the unit being repaired. I dont think the regulators are an issue.
I checked the outputs on the scope on the working 3000 and the drains for 8 outputs have a square waveform and the other 8 the gates have a square waveform.
When testing the bad 3000 I can kinda of see the waveform but its pulsing very fast and hard to read.
Something is causing the output side of the board to pulse all of the signals all over the board, I think something from the power supply is perhaps sending a faulty signal to the output board and causing havoc but I am not for sure.
No it reads 0.000 ohms so I have to assume its ok.
What about the LM339 the U1 not the U5. It reads as follows......
Pin 1: 4.10
pin 2: 4.10
Pin 3: 16.0-17.0 fluctuating
pin 4: 4.35
pin 5: 4.98
pin 6: 4.98
pin 7: 8.20
pin 8: 4.33
pin 9: 2.750
pin10: 0.161
pin11: 1.630
pin12: 0.001
pin13: 5.0-7.0 bouncing all over the place
pin14: 0.075
pins 4-7 are inputs as well as pins 8-11.
3 being vcc and 12 being ground.
pins 4 and 5 feed pin 2 (1out)
pins 6 and 7 feed pin 1 (2out)
pins 10 and 11 feed pin 13 (4out)
Pins 8 and 9 feed pin 14 (3out)
Pin 14 has no output and I was wondering if the output from 14 supplied the 6 volts for the on delay?
I have been looking at the schematic closely and trying to determine if the right pins have the right voltage. I am not sure what some of the abbreviations mean though. As far as like P.S, S.D, and SD
For some reason when I test pin 11 for voltage the amp goes into protect and then the thermal light flashes on and off and the protect light is on but flickering.
I dont know if its relavent but thought it was kinda strange. What do you think?
What about the LM339 the U1 not the U5. It reads as follows......
Pin 1: 4.10
pin 2: 4.10
Pin 3: 16.0-17.0 fluctuating
pin 4: 4.35
pin 5: 4.98
pin 6: 4.98
pin 7: 8.20
pin 8: 4.33
pin 9: 2.750
pin10: 0.161
pin11: 1.630
pin12: 0.001
pin13: 5.0-7.0 bouncing all over the place
pin14: 0.075
pins 4-7 are inputs as well as pins 8-11.
3 being vcc and 12 being ground.
pins 4 and 5 feed pin 2 (1out)
pins 6 and 7 feed pin 1 (2out)
pins 10 and 11 feed pin 13 (4out)
Pins 8 and 9 feed pin 14 (3out)
Pin 14 has no output and I was wondering if the output from 14 supplied the 6 volts for the on delay?
I have been looking at the schematic closely and trying to determine if the right pins have the right voltage. I am not sure what some of the abbreviations mean though. As far as like P.S, S.D, and SD
For some reason when I test pin 11 for voltage the amp goes into protect and then the thermal light flashes on and off and the protect light is on but flickering.
I dont know if its relavent but thought it was kinda strange. What do you think?
Yes it did have +6v on the good amp.
I somehow got my pins mixed up on the amp we are testing. Probably late and very tired.
U304
pin1: -4.66
pin2: 0.072
pin3: -4.38
pin4: -5.96
pin5: 2.173
pin6: 0.275
pin7: 5.49
pin8: 6.09
U306
pin1: -4.37
pin2: -1.636
pin3: -1.678
pin4: -5.96
pin5: 0.001
pin6: -0.008
pin7: 4.37
pin8: 6.09
So I am getting the positive 6v on the pin 8 on both op-amps
I changed U304, U306, and U307 and the amp still is doing the exact same thing.
I somehow got my pins mixed up on the amp we are testing. Probably late and very tired.
U304
pin1: -4.66
pin2: 0.072
pin3: -4.38
pin4: -5.96
pin5: 2.173
pin6: 0.275
pin7: 5.49
pin8: 6.09
U306
pin1: -4.37
pin2: -1.636
pin3: -1.678
pin4: -5.96
pin5: 0.001
pin6: -0.008
pin7: 4.37
pin8: 6.09
So I am getting the positive 6v on the pin 8 on both op-amps
I changed U304, U306, and U307 and the amp still is doing the exact same thing.
I had a similar issue with one of these amps. I somehow get the feeling people try to over-drive the input on these with bass boost, eq boost, full gain, and easy clipping. Something tells me the TL072 opamps cant take that much abuse, possibly due to regulated voltage levels or lack of protection on the opAmp inputs.
I even found one time that DC offset wasnt an issue, but the sound passing through was. If you throw a sine wave through the RCAs, you should be able to see the same wave of different amplitude on your scope; that is depending on the crossove and switch settings. In any case, if you have a sine wave on any of the opamp input pairs or outputs, then all 3 audio pins on that side of the opAmp should likely read something of the inputed sine wave. Again, I've found at least one case where a stuborn opamp had sound on input pins but nothing on output - not even DC, and the opamp was bad.
I even found one time that DC offset wasnt an issue, but the sound passing through was. If you throw a sine wave through the RCAs, you should be able to see the same wave of different amplitude on your scope; that is depending on the crossove and switch settings. In any case, if you have a sine wave on any of the opamp input pairs or outputs, then all 3 audio pins on that side of the opAmp should likely read something of the inputed sine wave. Again, I've found at least one case where a stuborn opamp had sound on input pins but nothing on output - not even DC, and the opamp was bad.
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These amps have problems with DC offset in the op-amps because there are so many in series and any amplification boosts the offset from the previous stages.
The op-amp will only have signal on all 3 pins of one channel if the non-inverting input has signal driven into it. If the non-inverting input is grounded (and therefore has no signal) and the input is fed into the inverting input, there will only be signal on the output of the op-amp unless the op-amp is driven into clipping. Then you may see signal on the inverting input but it will likely be very distorted.
The op-amp will only have signal on all 3 pins of one channel if the non-inverting input has signal driven into it. If the non-inverting input is grounded (and therefore has no signal) and the input is fed into the inverting input, there will only be signal on the output of the op-amp unless the op-amp is driven into clipping. Then you may see signal on the inverting input but it will likely be very distorted.
I have one of these amps T-30001bd which currently blew on me. I opened it up and from what little I believe 8 mosfets look like they opened up. The amp powers on just fine. just no sound. I talked to Rockford and that Quoted me $454 for repair. Is there anyone here that could repair this amp for me cheaper then that?
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