My mtx7801 amp was running and voltage dropped below 10v
Amp stopped working. No power lights, no protection circut light, took amp apart and hooked up power and led 401 service light is blinking, no obvious part failure on board, where do i start testing.
I believe amp was repaired in past, cannot upload puc files are too big. Guessing its a fet attached to heatsink. Will link thread with pic that matches mine, explenation of whats going on?
Amp stopped working. No power lights, no protection circut light, took amp apart and hooked up power and led 401 service light is blinking, no obvious part failure on board, where do i start testing.
I believe amp was repaired in past, cannot upload puc files are too big. Guessing its a fet attached to heatsink. Will link thread with pic that matches mine, explenation of whats going on?
Don't link. Reduce the file sizes and post photos through forum.
Only post photos of YOUR amplifiers.
Have you ever repaired an amplifier?
What test equipment do you have?
Only post photos of YOUR amplifiers.
Have you ever repaired an amplifier?
What test equipment do you have?
I have only fixed amplifiers due to poor connections via resoldering, cleaning corrosion, desoldering and reapplying thermal paste...
I have minimal experience with deducing problems due to voltage/ohm readings but am ready to learn.
I have makeshift 12v dc power supply, and a cheap multimeter for test equipment
I have minimal experience with deducing problems due to voltage/ohm readings but am ready to learn.
I have makeshift 12v dc power supply, and a cheap multimeter for test equipment
Attachments
Do NOT apply power without having all heatsink mounted components clamped tightly to the heatsink.
The resolution of that photo is far too low to see anything. What is it supposed to show?
The LED you mentioned only means that voltage is present.
This site can accept much larger images. Sample attached.
The resolution of that photo is far too low to see anything. What is it supposed to show?
The LED you mentioned only means that voltage is present.
This site can accept much larger images. Sample attached.
Attachments
Just leave it for now.
Check all of the heatsink-mounted components between legs of the individual components in the following order. Which ones read 0 ohms and between which legs? Check with no power applied.
Leg 1-2
1-3
2-3
Check all of the heatsink-mounted components between legs of the individual components in the following order. Which ones read 0 ohms and between which legs? Check with no power applied.
Leg 1-2
1-3
2-3
Fet103 leg 1-3 0 ohm
Fet107 leg 1-3 0 ohm
Fet105 leg 1-3 0 ohm
Fet111 leg 1-3 0 ohm
Fet109 leg1-3 0 ohm
Unable to test without removing capacitor
Rec 106
Rec107
Fet191
Fet402
Fet412
Fet410 no ohm reading
Fet406 no ohm reading
Unable to test without removing capacitor
Fet409
Fet413
Fet405
Fet403
Fet 401
Fet192
Rec100
Rec102
Fet112 leg 1-3 0 ohm
Fet110 leg 1-3 0 ohm
Fet106 leg 1-3 0 ohm
Fet108 leg 1-3 0 ohm
Fet105 leg 1-3 0 ohm
Fet107 leg 1-3 0 ohm
Fet105 leg 1-3 0 ohm
Fet111 leg 1-3 0 ohm
Fet109 leg1-3 0 ohm
Unable to test without removing capacitor
Rec 106
Rec107
Fet191
Fet402
Fet412
Fet410 no ohm reading
Fet406 no ohm reading
Unable to test without removing capacitor
Fet409
Fet413
Fet405
Fet403
Fet 401
Fet192
Rec100
Rec102
Fet112 leg 1-3 0 ohm
Fet110 leg 1-3 0 ohm
Fet106 leg 1-3 0 ohm
Fet108 leg 1-3 0 ohm
Fet105 leg 1-3 0 ohm
My leads on my multimeter are not long enough, and the caps are pretty big right on top of the fets
Revised list tested all components attached to heat sink
Fet103 leg 1-3 0 ohm
Fet107 leg 1-3 0 ohm
Fet105 leg 1-3 0 ohm
Fet111 leg 1-3 0 ohm
Fet109 leg1-3 0 ohm
Rec 106
Rec107
Fet191
Fet404
Fet402
Fet412
Fet410
Fet406
Fet409
Fet413
Fet411
Fet405
Fet403
Fet 401
Fet192
Rec100
Rec102
Fet112 leg 1-3 0 ohm
Fet110 leg 1-3 0 ohm
Fet106 leg 1-3 0 ohm
Fet108 leg 1-3 0 ohm
Fet105 leg 1-3 0 ohm
Fet103 leg 1-3 0 ohm
Fet107 leg 1-3 0 ohm
Fet105 leg 1-3 0 ohm
Fet111 leg 1-3 0 ohm
Fet109 leg1-3 0 ohm
Rec 106
Rec107
Fet191
Fet404
Fet402
Fet412
Fet410
Fet406
Fet409
Fet413
Fet411
Fet405
Fet403
Fet 401
Fet192
Rec100
Rec102
Fet112 leg 1-3 0 ohm
Fet110 leg 1-3 0 ohm
Fet106 leg 1-3 0 ohm
Fet108 leg 1-3 0 ohm
Fet105 leg 1-3 0 ohm
Was the amp doing the same thing in the vehicle?
Are you 100% sure that your power supply can deliver the necessary inrush current to get the amp up and running?
Are you 100% sure that your power supply can deliver the necessary inrush current to get the amp up and running?
I had the big 3 upgrade in the vehichle with an additional battery, but no aftermarket alternator.
There was a stock voltmeter in the vehicle and i struck a hard note while idiling, and the voltage dropped drastically. The amp shut off. This was about 6 months ago and i just got around to trying to figure out whats going on.
The power supply im using is a basic 12v wall adapter.
There was a stock voltmeter in the vehicle and i struck a hard note while idiling, and the voltage dropped drastically. The amp shut off. This was about 6 months ago and i just got around to trying to figure out whats going on.
The power supply im using is a basic 12v wall adapter.
While the cover is off, see if the output filter inductors have any broken terminals.
You need to try it in the vehicle again. You could have excessive resistance at some point.
I'd insert a 20 amp ATC/ATO fuse in series with the amp's B+ terminal in case the amp has a problem.
Try powering it up. If it doesn't power up, start checking the voltage across the amp's B+ and ground terminals.
If it's too low, check voltage at the battery. If there is little to no voltage drop there, check the voltage at every point where there is a connection in the B+ power line between the amp and battery to see if you can find the bad connection.
You need to try it in the vehicle again. You could have excessive resistance at some point.
I'd insert a 20 amp ATC/ATO fuse in series with the amp's B+ terminal in case the amp has a problem.
Try powering it up. If it doesn't power up, start checking the voltage across the amp's B+ and ground terminals.
If it's too low, check voltage at the battery. If there is little to no voltage drop there, check the voltage at every point where there is a connection in the B+ power line between the amp and battery to see if you can find the bad connection.
I checked voltage while i had it powered off my wall adapter it was 12.4v at the terminals
I no longer have the vehicle, it was a work vehicle and the transmission went so i got a new vehicle, with has smaller space, im running a smaller amp in there, its in the shop right now, when i get it back ill finish installing the new wiring and test in the vehicle like you said.
When i have it powered up no lights will come on except the service light, even with the 12.4v
I no longer have the vehicle, it was a work vehicle and the transmission went so i got a new vehicle, with has smaller space, im running a smaller amp in there, its in the shop right now, when i get it back ill finish installing the new wiring and test in the vehicle like you said.
When i have it powered up no lights will come on except the service light, even with the 12.4v