First post new member 
. I have had this amp stashed away for years I can't remember exactly what happened when i quit using it. I believe I had accidentally shorted B+ to speaker outputs or RCA maybe, I'm just not certain. I'm a DIY type of guy and am always up for learning so browsing the web I came upon this great forum. I've been lurking and soaking up as much information as I can in the last week or so from the different threads and similar amps to mine. I'm a bit overwhelmed with it so I would like if someone could please point me in a direction to start.
Amp blows fuse as soon as REM is connected. In the house I'm using a PC power supply to provide 12.5V.
There's no visible signs of any overheated or burnt parts. I found a few blown output FETS from each channel and the source resistors from the blown Fets were out of tolerance, I've clipped the legs from all outputs on both channels.
i've tested the pins using REM and Amp GND, no B+
494C
1: 45.9mv
2: 4.61v
3: 51.5mv
4: 1.9mv
5: 1.46v
6: 3.26v all PS FETS gate legs read 4.72v
7: .8mv
8: 11.79v
9: 4.66v
10: 4.66v
11: 11.79v
12: 11.74v
13: 4.87v
14: 4.87v
15: 4.87v
16: .9mv
LM339
1: .294mv
2: .494mv
3: 11.79v
4: .183mv
5: 2.37v
6: 4.87v
7: 5.32v
8: 3.92v
9: 4.87v
10: 4.87v
11: 7.4v
12: .8mv
13: 4.94v
14: 4.94v
with B+ and GND all PS Fets read 12.5 on drain legs. I don't know if this information is relevant but assuming it could help.
I'd really appreciate it if somebody could point me in the right direction from here, Thanks.
. I have had this amp stashed away for years I can't remember exactly what happened when i quit using it. I believe I had accidentally shorted B+ to speaker outputs or RCA maybe, I'm just not certain. I'm a DIY type of guy and am always up for learning so browsing the web I came upon this great forum. I've been lurking and soaking up as much information as I can in the last week or so from the different threads and similar amps to mine. I'm a bit overwhelmed with it so I would like if someone could please point me in a direction to start.Amp blows fuse as soon as REM is connected. In the house I'm using a PC power supply to provide 12.5V.
There's no visible signs of any overheated or burnt parts. I found a few blown output FETS from each channel and the source resistors from the blown Fets were out of tolerance, I've clipped the legs from all outputs on both channels.
i've tested the pins using REM and Amp GND, no B+
494C
1: 45.9mv
2: 4.61v
3: 51.5mv
4: 1.9mv
5: 1.46v
6: 3.26v all PS FETS gate legs read 4.72v
7: .8mv
8: 11.79v
9: 4.66v
10: 4.66v
11: 11.79v
12: 11.74v
13: 4.87v
14: 4.87v
15: 4.87v
16: .9mv
LM339
1: .294mv
2: .494mv
3: 11.79v
4: .183mv
5: 2.37v
6: 4.87v
7: 5.32v
8: 3.92v
9: 4.87v
10: 4.87v
11: 7.4v
12: .8mv
13: 4.94v
14: 4.94v
with B+ and GND all PS Fets read 12.5 on drain legs. I don't know if this information is relevant but assuming it could help.
I'd really appreciate it if somebody could point me in the right direction from here, Thanks.
First check all Power stage mosfet transistors D-S & G-D-S if they 0 ohm? you need to replace them, and check also all 10 ohm gate resistors.
if all the Power mosfet transistors are OK remove 1 leg of each 0.1 ohm resistor (10 resistors) and see now if the fuse is blow. if not? the problem is at the Power Stage area. if the fuse keep blow the problem came from the Power supply unit it can be many things like bad LM317/337 or rectifier diodes or Power supply mosfet gate resistors or... the power suplly mosfet/mosfet drivers
if all the Power mosfet transistors are OK remove 1 leg of each 0.1 ohm resistor (10 resistors) and see now if the fuse is blow. if not? the problem is at the Power Stage area. if the fuse keep blow the problem came from the Power supply unit it can be many things like bad LM317/337 or rectifier diodes or Power supply mosfet gate resistors or... the power suplly mosfet/mosfet drivers
When I said amp blows fuse, that was back when I was using it and I believe it was a 60A external by the vehicle battery. Now it would kick off my PC power supply when i connect REM after i have B+ and GND already connected. After your question I took it out to a 12v car battery and had 60A fuse inline B+, GND, and when i connected REM I got heavy spark but fuse didn't blow. My power light isn't on and i think i might have seen it on then off fast like a fuse would blow. I grabbed my DMM and had 8.7 on PS gates and 12.35 on drains, source .003
regulators had +48 and -48 on one of the legs. Does that sound fine? i checked the power light pads and there was 48 volts going to it.
regulators had +48 and -48 on one of the legs. Does that sound fine? i checked the power light pads and there was 48 volts going to it.
When testing, it's rare to need anything more than a 15-20 amp ATO/ATC type fuse. Using a smaller fuse offers more protection to the components in the amp if something is wrong with it.
It sounds like the power supply is operating. The op-amps should have approximately ±16v on the power supply pins.
It sounds like the power supply is operating. The op-amps should have approximately ±16v on the power supply pins.
It's possible that the LED is defective (rare but it happens).
The turn-on terminal has bad solder connections.
Expect a lot of bad SMD components in the audio section. The following is what Rockford recommends (assuming yours is the same amp).
Search this forum for 800a2 and Q11. It will help prevent blowing outputs if you miss something.
The turn-on terminal has bad solder connections.
Expect a lot of bad SMD components in the audio section. The following is what Rockford recommends (assuming yours is the same amp).
Search this forum for 800a2 and Q11. It will help prevent blowing outputs if you miss something.
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