This is my first foray into class D amplifier repair, and so far I am stumped.
I purchased this amp on ebay for a very good price, but unfortunately it arrived damaged. Instead of sending it back, the seller just issued a full refund and told me to keep it. I was told that the amplifier worked, but it was pulled from an install, so who knows.
This is a 4 channel (4 in/4 out) amp that will not turn on.. or off. (Power LED is lit and the switching power xfmer hums away regardless of position) The power switch is not inline with the 120v line voltage entering the unit, and is instead controlled (presumably) by a combination of relays and IC's or some discreet array. Schematics are not available for this amp, so it's really hard (for me) to know.
The mosfets and voltage regulators test good. Fuses are fine. The relays also test good, however, one of the relays that is responsible for supplying 120v line voltage to the amplifier PCBs is not receiving the 24VDC at the coil necessary to engage the line voltage. This is only a symptom, though, and not the cause. I tried supplying 120v directly to the amp boards and no luck.
Unfortunately, there isn't a single component on any of the PCBs that appear to be "fried". Everything looks fine. I'm attaching a couple of photos of the board. Sorry for the atrocious quality; my camera is also dying! My hope is that someone can identify the topology and offer a jumping-off point.
I purchased this amp on ebay for a very good price, but unfortunately it arrived damaged. Instead of sending it back, the seller just issued a full refund and told me to keep it. I was told that the amplifier worked, but it was pulled from an install, so who knows.
This is a 4 channel (4 in/4 out) amp that will not turn on.. or off. (Power LED is lit and the switching power xfmer hums away regardless of position) The power switch is not inline with the 120v line voltage entering the unit, and is instead controlled (presumably) by a combination of relays and IC's or some discreet array. Schematics are not available for this amp, so it's really hard (for me) to know.
The mosfets and voltage regulators test good. Fuses are fine. The relays also test good, however, one of the relays that is responsible for supplying 120v line voltage to the amplifier PCBs is not receiving the 24VDC at the coil necessary to engage the line voltage. This is only a symptom, though, and not the cause. I tried supplying 120v directly to the amp boards and no luck.
Unfortunately, there isn't a single component on any of the PCBs that appear to be "fried". Everything looks fine. I'm attaching a couple of photos of the board. Sorry for the atrocious quality; my camera is also dying! My hope is that someone can identify the topology and offer a jumping-off point.
