I'm Repairing my Audiobahn a18001DT sub amp and I have many questions and hope to get help.
This is what I have found so far 6 of the 16 IRFZ44N Power Mosfets Fried and the inductor the goes on the speaker output leads.
This is what I want to replace:
The Mosfet controller chip (KA3525A)
The 8 Mosfet Drivers ( (4)KSC2316.(4)KSA916)
The Voltage Regulators (MC7818CT)(L7915ACT)
The 16 IRFZ44N mosfets
And im going to rewind the inductor
Any input on what else I should be looking for or if I need anything else or am I buying parts I dont need?
This is what I have found so far 6 of the 16 IRFZ44N Power Mosfets Fried and the inductor the goes on the speaker output leads.
This is what I want to replace:
The Mosfet controller chip (KA3525A)
The 8 Mosfet Drivers ( (4)KSC2316.(4)KSA916)
The Voltage Regulators (MC7818CT)(L7915ACT)
The 16 IRFZ44N mosfets
And im going to rewind the inductor
Any input on what else I should be looking for or if I need anything else or am I buying parts I dont need?
If you haven't done so yet, pull the power supply FETs.
Power up the amp and measure the DC voltage on the gate pads of the power supply FET locations. All should read near 1/2B+. If so, the driver transistors and the 3525 are likely OK.
The FETs are in 4 groups. If you have 4, 8, 12 or 16 that read too high or too low, one or more of the driver transistors is likely defective. If only one or two read too low, you likely have defective gate resistors.
Measure the resistance across EACH gate resistor. If they're out of tolerance (±5%), replace them.
The green and yellow inductor is for the power supply rails.
The two larger diameter inductors are for the audio. Often these short. If there are any signs of a light colored dust where the last winding goes over the top of the coil, it's likely that the insulation is failing or has failed and this will need to be repaired before the amp is put back into service.
The voltage regulators are likely OK. I've never had to replace one in this type of amp.
Power up the amp and measure the DC voltage on the gate pads of the power supply FET locations. All should read near 1/2B+. If so, the driver transistors and the 3525 are likely OK.
The FETs are in 4 groups. If you have 4, 8, 12 or 16 that read too high or too low, one or more of the driver transistors is likely defective. If only one or two read too low, you likely have defective gate resistors.
Measure the resistance across EACH gate resistor. If they're out of tolerance (±5%), replace them.
The green and yellow inductor is for the power supply rails.
The two larger diameter inductors are for the audio. Often these short. If there are any signs of a light colored dust where the last winding goes over the top of the coil, it's likely that the insulation is failing or has failed and this will need to be repaired before the amp is put back into service.
The voltage regulators are likely OK. I've never had to replace one in this type of amp.
all of the gates are at half and the Green/Copper inductor had 5 wires burned in half all in different spots
Don't forget to check EACH of the gate resistors for the FETs. If one is out of tolerance, the new FETs will be destroyed.
Checking the 'voltage' on each gate pad isn't going to tell you if the gate resistors are OK. A resistor that's 400 ohms will give essentially the same voltage reading as a 100 ohm resistor but the defective 400 ohm resistor (it should be 100 ohms) may cause the FETs to fail.
When you power up the amp (after replacing the FETs), do so through a 10 amp fuse. If the fuse blows when remote voltage is applied, there is a problem. Do NOT use a larger fuse.
Have the transistors tightly clamped to the heatsink BEFORE applying power (after the new power supply FETs are installed).
Checking the 'voltage' on each gate pad isn't going to tell you if the gate resistors are OK. A resistor that's 400 ohms will give essentially the same voltage reading as a 100 ohm resistor but the defective 400 ohm resistor (it should be 100 ohms) may cause the FETs to fail.
When you power up the amp (after replacing the FETs), do so through a 10 amp fuse. If the fuse blows when remote voltage is applied, there is a problem. Do NOT use a larger fuse.
Have the transistors tightly clamped to the heatsink BEFORE applying power (after the new power supply FETs are installed).
There are 100 ohm resistors at each gate they are all ok. Sorry I didnt mention that they were all 99.x ohms. What else should I look for?
Those are not used like the FETs in the power supply. The voltages you were looking for at the FET locations don't apply to anything other than power supply FETs.
The regulators will have no voltage on them until the FETs are replaced and the amp is powered up. They are completely isolated from the failed component. There is virtually no chance that they are defective.
Were the burned winding on the inductor burned between layers or on the outer layer (shorted to the bottom cover)?
The regulators will have no voltage on them until the FETs are replaced and the amp is powered up. They are completely isolated from the failed component. There is virtually no chance that they are defective.
Were the burned winding on the inductor burned between layers or on the outer layer (shorted to the bottom cover)?
It was burnt on both coils and by burnt wires melted in half it was on both the windings of wires on it and they were mostly right before they bent over the top and bottom.
what in the bloody hell happened to your audiobahn amp! i had 3 amps so far , an a8002t , it blew up and it turned out it was only the switching power suply controler that fried , i had an a2x400hq rack mount amp that also blew up because of me , i forgot tpo tighten the speaker wires so they shorted together , and it turned out it was only 2 out puts 2sa1217 ithink? and 1 irfz44n in the input ....
if everything you said is true , your board probably sustained heavy damage! , im sorry to tell you that but , change the whole amp ?
if everything you said is true , your board probably sustained heavy damage! , im sorry to tell you that but , change the whole amp ?
I have a good one (A18001DQ) I saw this one and thought it was worth fixing but has been showing other wise
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.Few months later still no issues its been in my car every day, playing everyday. Im pleased at being 17 years old and be able to do this kind of work. I also have another Audiobahn amp I want to fix (works fine just is on all the time remote deosnt matter). Thanks again for anyone who has helped/ helps me out!
The most likely culprit is Q303 (2sd600) shorted or leaking (electrically) but Q301 or Q302 could also cause that problem.
You should also remove the remote wire from the remote terminal to see if 12 volts is present on the terminal of the amplifier (it shouldn't have any voltage on it).
You should also remove the remote wire from the remote terminal to see if 12 volts is present on the terminal of the amplifier (it shouldn't have any voltage on it).
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