What happens if you short the shield to the RCA center conductor on the board? Is it still noisy?
I just ran across another problem. Rectifiers BR1 and BR2. BR1 voltage on center leg referenced to ground is 117.6vdc. BR2 voltage on center leg referenced to ground is -61.1vdc.
With the ground on the same point, what's the DC voltage on the secondary ground?
What's the DC voltage across the speaker terminals?
What's the DC voltage across the speaker terminals?
DC voltage at (-)speaker terminal referenced to battery ground is .006vdc. DC voltage across speaker terminals is -3.63vdc.
Are you sure that the voltages on the rectifiers is correct?
Are the rectifiers doublers or are they normal center-tapped rectifiers?
With nothing connected to the amp, what's the resistance between the negative speaker terminal and the primary ground?
Are the rectifiers doublers or are they normal center-tapped rectifiers?
With nothing connected to the amp, what's the resistance between the negative speaker terminal and the primary ground?
I was just double checking the rectifier voltages. BR1 reads 63.3vdc when the remote is applied, then jumps to as high as 120vdc when the relay clicks on. BR2 reads -63.3vdc when the remote is applied, then drops slightly to -61.1vdc.
The rectifiers are center tapped. FMG-G33R and FMG-G33S.
Resistance between battery ground terminal and (-)speaker terminal is 978ohms.
The rectifiers are center tapped. FMG-G33R and FMG-G33S.
Resistance between battery ground terminal and (-)speaker terminal is 978ohms.
Yes, but I also discovered that it only does that with a speaker connected. Without a speaker connected BR1 reads 63.1 and BR2 reads -63.1. I get the same readings across the caps.
That sounds like there is a drive problem (likely on the driver board) for the high-side FETs.
The positive rail caps may be damaged if the amp didn't draw excessive current at 120v.
The positive rail caps may be damaged if the amp didn't draw excessive current at 120v.
I had the current limited to 4.5A and only kept the remote on long enough to get the readings. Would the next step be to pull the output fets?
Using the differential probe, do you have a good drive signal on the high-side FETs gate to source?
