If you cut that transistor out of the circuit, do any others read as shorted?
If it appears that another 4 are shorted, find the one with the lowest resistance from the gate to the collector and cut it out.
When working on these amps (any of the older BD amps), you must discharge the rail caps before doing any testing. The caps can remain charged at 100+V for a days. You need to discharge them through a resistor. If you don't have a resistor, you can use an ordinary incandescent light bulb that's used with mains voltage.
When you are testing with the caps charged, it's possible to short the high voltage to another component without knowing it.
If it appears that another 4 are shorted, find the one with the lowest resistance from the gate to the collector and cut it out.
When working on these amps (any of the older BD amps), you must discharge the rail caps before doing any testing. The caps can remain charged at 100+V for a days. You need to discharge them through a resistor. If you don't have a resistor, you can use an ordinary incandescent light bulb that's used with mains voltage.
When you are testing with the caps charged, it's possible to short the high voltage to another component without knowing it.
Yes, I may have been that,
Q105 is out of circuit, I have checked and have short, in the three-pin,
I will replace the four IRF3415, if I have these in my closet.
I do not know ... is whether to also replace, the IRF6215 (Q110, 111.112 and Q25)
I get very strange values ...
again, thank you, Perry
Q105 is out of circuit, I have checked and have short, in the three-pin,
I will replace the four IRF3415, if I have these in my closet.
I do not know ... is whether to also replace, the IRF6215 (Q110, 111.112 and Q25)
I get very strange values ...
again, thank you, Perry
Generally, when one FET explodes, at least one of the other polarity in the same group fail.
Do you read a short across the drain and source of any of the 6215s?
Are you tinning the backs of them before you install them?
Do you read a short across the drain and source of any of the 6215s?
Are you tinning the backs of them before you install them?
If the backs of the fet, provided the salary before testing,
I do not read through the short 6215 .... I do not know if you take them out, and check out, what do you think?
I do not read through the short 6215 .... I do not know if you take them out, and check out, what do you think?
If you read an open circuit between the gate legs and the other legs, they may have survived. Be aware, though, if one is injured, when the amp is powered up it could destroy the FETs again.
I don't understand 'salary'.
I don't understand 'salary'.
The 6215 according to my measurements, I think we have survived.
The Q105 burned, then connect the speaker (without connecting the speaker, the amplifier was stable)
salary,,,,? forgiveness is the translator. (salary = soldier)
I wanted to say was:
whenever I connect the amplifier to prove, all fet, soldiers strip MEHSA
Today it's late, tomorrow, will connect the amplifier again, to see that this ....
The Q105 burned, then connect the speaker (without connecting the speaker, the amplifier was stable)
salary,,,,? forgiveness is the translator. (salary = soldier)
I wanted to say was:
whenever I connect the amplifier to prove, all fet, soldiers strip MEHSA
Today it's late, tomorrow, will connect the amplifier again, to see that this ....
I changed the four IRF3415, and (Perry was right)
When connected, LED protection two seconds on and off, and ..... five seconds, I saw some smoke, from R107, I disconnected the battery, I downloaded the 121v, and I checked Q111 (IRF6215), and had a short between pin 1 and pin 2. (This short, I was not before connecting the amplifier, comes after)
What makes me think that this transistor was leaky, and the plug should have finished burning.
I have to order more transistors , I'll wait another two weeks .....
When connected, LED protection two seconds on and off, and ..... five seconds, I saw some smoke, from R107, I disconnected the battery, I downloaded the 121v, and I checked Q111 (IRF6215), and had a short between pin 1 and pin 2. (This short, I was not before connecting the amplifier, comes after)
What makes me think that this transistor was leaky, and the plug should have finished burning.
I have to order more transistors , I'll wait another two weeks .....
I keep thinking, and I made some measurements in U10 and U6.
with the probe of the multimeter on pin 1
U6
pin2: 369
pin3: 918
pin5: 1.26 K
U10
pin2: 369
pin3: 1.36 K
pin5: 1.60 K
Are these values correct?
with the probe of the multimeter on pin 1
U6
pin2: 369
pin3: 918
pin5: 1.26 K
U10
pin2: 369
pin3: 1.36 K
pin5: 1.60 K
Are these values correct?
Nothing there indicates that they're shorted but in-circuit testing isn't definitive and even if they check OK with a multimeter, they may not perform as they should for high-speed switching. This is why it's important to have a scope for class D amps.
Search for the thread where a potentiometer was used to force the outputs to switch on a rockford BD amp. That's one way to check the drive circuit. It doesn't determine high frequency performance but it tells you if all of the components are functioning at a basic level.
Search for the thread where a potentiometer was used to force the outputs to switch on a rockford BD amp. That's one way to check the drive circuit. It doesn't determine high frequency performance but it tells you if all of the components are functioning at a basic level.
http://www.diyaudio.com/forums/car-audio/186242-rockford-fosgate-bd15001.html
Here is the link to save you some time from searching. Hope it helps, if you need any help just ask.
Here is the link to save you some time from searching. Hope it helps, if you need any help just ask.
Thanks Perry, I will look at the link. (thanks also Seankane)
Anyway, I'm still looking for a scope ... I wish I had one ...
When I know more of the amplifier, I'll say
Anyway, I'm still looking for a scope ... I wish I had one ...
When I know more of the amplifier, I'll say
Just one question ...
This adjustable potentiometer test ¿I can do without the eight soldiers to mosfet circuit board?
(I mean, eight transistors that failed in the beginning of the repair)
If so, I can start testing with the multimeter probes directly on the PCB?
This adjustable potentiometer test ¿I can do without the eight soldiers to mosfet circuit board?
(I mean, eight transistors that failed in the beginning of the repair)
If so, I can start testing with the multimeter probes directly on the PCB?
You should be able to test it without 8 FETs but you won't be able to see if the drains are switching for the missing FETs.
I have new measures, (as I send the new parts, not bored ...)
All these measures, I have done without: Q109, Q104, Q105, Q106, Q8, Q110, Q111, Q112, Q25, all of these out of the motherboard.
U11
Pin 1: 0
Pin 2: 0
Pin 3: 0
Pin 4: -9.92
Pin 5: 0
Pin 6: 0
Pin 7: 0
Pin 8: 9.78
U4
Pin 1: 0.04
Pin 2: 0.35
Pin 3: 0.35
Pin 4: -9.92
Pin 6: 0.66
Pin 7: 0.66
Pin 8: 9.78
I think these are fine.
U17
Pin 1: 0
pin 2: 0
Pin 3: 0
pin 4: -9.91
pin 5: 0
pin 6: -0.98
pin 7: 9.78
pin 8: 0
U5
Pin 1: 0
Pin 2: -0.94
Pin 3: 0
pin 4: -9.91
pin 5: 0
pin 6: 1.36
pin 7: 9.78
pin 8: 0
as pin 6 of U5, should not be negative?
U10
Pin 1: -9.66
pin 2: -9.70
Pin 3: 9.78
pin 4: -9.70
pin 5: -9.71
U6
Pin 1: -8.25
pin 2: -9.95
Pin 3: 9.78
pin 4: -9.95
pin 5: 1.43
the latter measure, pin 5, should not be greater? What well be negative?
All these measures, I have done without: Q109, Q104, Q105, Q106, Q8, Q110, Q111, Q112, Q25, all of these out of the motherboard.
U11
Pin 1: 0
Pin 2: 0
Pin 3: 0
Pin 4: -9.92
Pin 5: 0
Pin 6: 0
Pin 7: 0
Pin 8: 9.78
U4
Pin 1: 0.04
Pin 2: 0.35
Pin 3: 0.35
Pin 4: -9.92
Pin 6: 0.66
Pin 7: 0.66
Pin 8: 9.78
I think these are fine.
U17
Pin 1: 0
pin 2: 0
Pin 3: 0
pin 4: -9.91
pin 5: 0
pin 6: -0.98
pin 7: 9.78
pin 8: 0
U5
Pin 1: 0
Pin 2: -0.94
Pin 3: 0
pin 4: -9.91
pin 5: 0
pin 6: 1.36
pin 7: 9.78
pin 8: 0
as pin 6 of U5, should not be negative?
U10
Pin 1: -9.66
pin 2: -9.70
Pin 3: 9.78
pin 4: -9.70
pin 5: -9.71
U6
Pin 1: -8.25
pin 2: -9.95
Pin 3: 9.78
pin 4: -9.95
pin 5: 1.43
the latter measure, pin 5, should not be greater? What well be negative?
I have also:
U15
Pin 1: 0
pin 2: 0.96
Pin 3: 0.40
pin 4: 0
pin 5: -9.92
pin 6: 0
pin 7: 0.05
pin 8: 9.78
U9
Pin 1: 0
pin 2: -4.48
Pin 3: -3.80
pin 4: 0
pin 5: -9.73
pin 6: 0
pin 7: -9.50
pin 8: 9.70
conclusion: U6 and U15 ¿defective?
Now, do not know what may have happened ...
I think I've taken a step backwards in this repair ...
I replaced:
U17, U6, U15, U5 and U14 (the latter I've put a socket)
When connecting the amplifier, there is high voltage (23v only)
Voltage U14
Pin 1: 4.9
pin 2: 0
Pin 3: 4.1
pin 4: 4.6
pin 5: 4.9
pin 6: 0
pin 7: 0
pin 8: 4.3
pin 9: 3.6
pin 10: 4.2
pin 11: 0
pin 12: 3.8
Pin 13: 0
Pin 14: 11.5
pin 15: 0
Pin 16: 0
Pin 17: 11.5
pin 18: 4.9
What do you think?
I think I've taken a step backwards in this repair ...
I replaced:
U17, U6, U15, U5 and U14 (the latter I've put a socket)
When connecting the amplifier, there is high voltage (23v only)
Voltage U14
Pin 1: 4.9
pin 2: 0
Pin 3: 4.1
pin 4: 4.6
pin 5: 4.9
pin 6: 0
pin 7: 0
pin 8: 4.3
pin 9: 3.6
pin 10: 4.2
pin 11: 0
pin 12: 3.8
Pin 13: 0
Pin 14: 11.5
pin 15: 0
Pin 16: 0
Pin 17: 11.5
pin 18: 4.9
What do you think?
Replace R34 (near U14) with a 1k ohm resistor. If you don't have a 1k resistor, I think the amp will work without it (for testing only).
Well, I'm here again
R34 replaced by a 1K
When connected, there is high voltage (126V) connected to the output speaker, the amplifier is stable, but to connect the input, there appears no sound, the output voltage of 0V is ...... Why?
R34 replaced by a 1K
When connected, there is high voltage (126V) connected to the output speaker, the amplifier is stable, but to connect the input, there appears no sound, the output voltage of 0V is ...... Why?
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