I tested the signal using a 9 volt battery,
they look OK excepts that there is 1 of the
4 signal that have 5.5 volts while the others
have 4.3.
they look OK excepts that there is 1 of the
4 signal that have 5.5 volts while the others
have 4.3.
When the battery was connected to the board, did they all read the same voltage if you measured the voltage on the battery?
I don't know if the 5v reading was taken before the 4v readings. Something could have drained the battery or something could be pulling it down. Either way, you need to perform whatever tests that you can to determine why the drive signals are different. You want to make absolutely sure that the drive circuit is OK before installing the output transistors.
My mistake! I replaced the four 2.2 ohms one watt resistors in front of the
Drive Board, but only 3 were open, as a result I ended up with 2 resistors
In parallel. So now everything is OK, can I test this amp with only one
transistor Per shoulder, Also the audio output transistor were replaced with
Irfp4004 is that the original audio output transistor for this amp?
Drive Board, but only 3 were open, as a result I ended up with 2 resistors
In parallel. So now everything is OK, can I test this amp with only one
transistor Per shoulder, Also the audio output transistor were replaced with
Irfp4004 is that the original audio output transistor for this amp?
Hi guys:
I'm ready to install the audio output mosfets to this amp, Can I install 1 MOSFET per bank?
Just to play it save
I'm ready to install the audio output mosfets to this amp, Can I install 1 MOSFET per bank?
Just to play it save
There isn't really any safe way to install FETs. With 1 per bank, it's likely to blow the FET if there is a problem. This will likely destroy the driver IC. If you install all of the FETs, the protection circuit will have a better chance of protecting the FETs but there's still a chance that 1 or more will fail if there is a problem.
It may be possible to modify the protection circuit to better protect the output transistors but I haven't tried it on these amps so I cannot give you any definitive information on modifying it.
If the drive signal looked OK and the amp doesn't have any shorted inductors, it should power up without any problems.
It may be possible to modify the protection circuit to better protect the output transistors but I haven't tried it on these amps so I cannot give you any definitive information on modifying it.
If the drive signal looked OK and the amp doesn't have any shorted inductors, it should power up without any problems.
Thanks again to all of you, especially Bobby for the help!
I finally got the mosfets installed and everything is working very nice.
I will be making a donation.
I finally got the mosfets installed and everything is working very nice.
I will be making a donation.
I'm trying to built an test fixture for this kind of boards, (audio driver board) but I need an schematic to do it.
does anybody have any schematic of an amp that uses this boar? I'm willing to pay for it.
Thanks in advance.
does anybody have any schematic of an amp that uses this boar? I'm willing to pay for it.
Thanks in advance.
I've had more experience since post #68 above. You can remove the rectifiers and test the amp with the outputs and driver board in place.
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