I don’t have any 47 ohm resistors on hand .
The amp is using IRFP064N with A1275,C3228 drivers . Would 22 ohm Gaye resistors work or should I wait and stick with the 47 ohm
The amp is using IRFP064N with A1275,C3228 drivers . Would 22 ohm Gaye resistors work or should I wait and stick with the 47 ohm
How do I check both muting transistors ?
The D1303 and the one on the driverboard ?
Amp had no output
The D1303 and the one on the driverboard ?
Amp had no output
Ok the muting transistors are fine .
I started looking at the audio driver board .
I found Q4,R21,D2 bad so far .
Wondering what would cause these parts to go bad ?
The owner stated the amp worked when he pulled it out of the vehicle he just saw a flash that’s why he brought it to me .
There is no way this amp worked when he brought it to me with these parts on the audio driver board being bad .
And since those parts are bad anything else I should check ?
This is the driver board that uses 4 of the IR21844S’s
I started looking at the audio driver board .
I found Q4,R21,D2 bad so far .
Wondering what would cause these parts to go bad ?
The owner stated the amp worked when he pulled it out of the vehicle he just saw a flash that’s why he brought it to me .
There is no way this amp worked when he brought it to me with these parts on the audio driver board being bad .
And since those parts are bad anything else I should check ?
This is the driver board that uses 4 of the IR21844S’s
That part of the drive circuit doesn't drive anything that can pass enough current to cause them to fail. As far as I can see, they only drive the input to the comparator on the PS driver board and C18 on that board.
Besides the driver ic’s being defective is there anything else on the audio driver board that could cause the outputs to blow ?
I replaced those parts i mentioned in a previous post soldered the board back in the amp and upon power up 2 of the outputs blew
I replaced those parts i mentioned in a previous post soldered the board back in the amp and upon power up 2 of the outputs blew
Shorted inductor, out of tolerance gate resistors, possibly defective components on the high-side supply for the drive IC...
I swapped driver boards and replaced the outputs .
Amp still had no output
I get no rail to rail oscillation on the outputs .
Any ideas on what to check
Amp still had no output
I get no rail to rail oscillation on the outputs .
Any ideas on what to check
Something is preventing the voltage from rising. It could be either on the main (muting transistor) or on the driver board.
I pulled the muting transistor and powered the amp up I know not a wise thing to do .
Amp has output .
Now I have to see if I have a D1303 off a junk board
Amp has output .
Now I have to see if I have a D1303 off a junk board
Either the one I pulled out of the junk board is bad or something else In that circuit is bad .
Could something else in the muting circuit be bad or more then likely the muting transistor is bad ?
Could something else in the muting circuit be bad or more then likely the muting transistor is bad ?
Was the original muting transistor defective?
There could be problems farther back in the circuit.
There could be problems farther back in the circuit.
I tried 3 different transistors to rule out that the muting transistor is defective .
With the muting transistor out the amp has output .
I know the audio driver board is good .
So where do I go from here what do I check
With the muting transistor out the amp has output .
I know the audio driver board is good .
So where do I go from here what do I check
I'd suggest connecting a jumper between the collector and emitter of Q10 to protect the outputs.
What's the DC voltage measured across the base and emitter of the muting transistor?
Measuring with and without the transistor in the circuit may be helpful.
What's the DC voltage measured across the base and emitter of the muting transistor?
Measuring with and without the transistor in the circuit may be helpful.
I blew the outputs again same bank so I’m gonna rebuild the driver board replace the outputs again .
There is also stuff that is defective on the main board by the muting transistor I found 1 of the diodes to be leaky .
Is the MMBTA42 on the audio driver board a sot-23 package ? Or a sot-23-3 package
There is also stuff that is defective on the main board by the muting transistor I found 1 of the diodes to be leaky .
Is the MMBTA42 on the audio driver board a sot-23 package ? Or a sot-23-3 package
Jump Q10. That will disable the output stage.
Those packages are the same. The -3 means 3 terminals. The SOT package can have up to 6 terminals.
Those packages are the same. The -3 means 3 terminals. The SOT package can have up to 6 terminals.