# 12v Power Supply Repair Question



## laughatthemall (Aug 3, 2015)

What would the next logical step to check be, for a power supply (N-ch enhancement MOSFETs SMP60N06) that has a gate drive signal when remote is applied (0v - 3.8v - 0v, 50% duty cycle, ~20khz, from TL494), 13.3v DC (constant) on the drain with or without remote, source grounded but does not pull any current or produce any output? I compared against a known good amp (older Orion) and the gate signal seems accurate, but with remote applied the drain should pulse 0v-26.6v (not happening). What else do I need, what might I be missing, to make a power supply function? I'm sure it's probably something basic, but I'm not understanding it. Thanks for any input/help you can provide!


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## GEM592 (Jun 19, 2015)

laughatthemall said:


> What would the next logical step to check be, for a power supply (N-ch enhancement MOSFETs SMP60N06) that has a gate drive signal when remote is applied (0v - 3.8v - 0v, 50% duty cycle, ~20khz, from TL494), 13.3v DC (constant) on the drain with or without remote, source grounded but does not pull any current or produce any output? I compared against a known good amp (older Orion) and the gate signal seems accurate, but with remote applied the drain should pulse 0v-26.6v (not happening). What else do I need, what might I be missing, to make a power supply function? I'm sure it's probably something basic, but I'm not understanding it. Thanks for any input/help you can provide!


Did you try posting this on diyaudio.com? Lots of posters there would probably be able to help.


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## laughatthemall (Aug 3, 2015)

I figured since it was a mobile (12v) amplifier, here might be the logical place to post it.


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## GEM592 (Jun 19, 2015)

laughatthemall said:


> I figured since it was a mobile (12v) amplifier, here might be the logical place to post it.


The Car Audio forum on diyaudio is going to be better for help with repairs. Look for Perry Babin, among others.


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## Justin Zazzi (May 28, 2012)

diyaudio is certainly going to be more help!

I was thrilled with the help I received troubleshooting an amplifier of my own over there.


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## jeffp (Jan 18, 2015)

Check the FET's they may be bad, but you will need to determine what caused the failure in the first place. its hard to give troubleshooting advice with no picture or with the info you have supplied. The FETS you have mentioned are readily available and are common for a PSU switcher. How old is the amp, and it may be best to start with a recap of the unit.


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