Rockford Fosgate 1500-1bd (2007)

[rhempz01]

I'm. Working on a Rockford Fosgate 1500-1bd at the moment. I just removed all the shorted components and removed the rectifiers and sodered in a regulator for testing purposes. Drive signals to the ps fets looks good, and I placed a few in the board for testing purposes. While I wait for the irfb3415's. I need some help with the output section. Viewing the drive signals. Should I remove all the output?

 

[rhempz01]

1500-1bd board

 

[Perry Babin]

Have you checked the output from all of the SMD regulators?

 

[rhempz01]

No I have not perry. I will do that.

 

[rhempz01]

What should I have on them? Should all output transistors be removed? With four in the board and 2 power supply mosfets none are getting hot. I have:
Q2012 leg 1: 11.83vdc leg 2: 20.69vdc leg 3: 11.21vdc
Q2010 leg 1: 11.83vdc leg 2: 20.69vdc leg 3. 11.20vdc
Q2001 leg 1: 6.25vdc. Leg 2: 20.68vdc leg 3 6.24vdc
Q2000 leg 1: -6.23vdc leg 2 -27.23vdc leg 3 -6.23vdc

 

[Perry Babin]

There is a graphic with the voltages. Navigate to the following page of the tutorial, item 24 on that page.
repair_tutorial/miscellaneousstuff/rockford/repairnotesrockford.htm

 

[rhempz01]

Ok thank you.

 

[rhempz01]

So yes perry my voltages are spot on with the graphic.

 

[rhempz01]

Ok so everything is good. Is the irfo3415 the OEM output transistor for this amplifier? Looking at max wattage that's 1600watts total? Wouldn't say irfp260 be a better replacement transistor? I already used the irfp3415, was just curious.

 

[Perry Babin]

The wattage rating is the dissipation that the transistor and package can withstand. In a switching circuit, there is very little power dissipation in the transistor.

The 3415 was used in some of the amps. I think I've seen the IRFP260N as well.

 

[rhempz01]

So all looked good with just the regulator in the amp when I attempted to power up the amp with the rectifiers installed the amp cycles from a stable 1.4amps to 4amps the power led flashes and back to normal....? Seems like the

 

[rhempz01]

Drive before resistor, 60r4 in all 6?

 

[Perry Babin]

How much current is your 12v supply rated for?

 

[rhempz01]

10amps

 

[Perry Babin]

Have you used that supply for amps like this before and they powered up normally?

 

[rhempz01]

Yes it is drawing 1.38amps at 12.7vdc then clicks and jumps to 5.43amps for 1 second. Like something is shorting when powered up or drive is lost for a second, maybe into protection and out. I'm not sure but it sounds like the ps mosfets are mphhs sound, power led flickers and back to normal this continues, nothing heats up. No outputs nor ps fets. Would the driver chip cause that?

 

[rhempz01]

When I tested the voltage regulator with amplifier in full power mode q2010 the amp stop cycling but the power supply was still slightly having the same syptoms. Going from the 1.38amps to 2.78. had black on ground and red on leg one of q2010. Are they bad or not grounded?

 

[rhempz01]

MJD45H11 I cant tmake out the part number on all of the transistors mounted to the board and could not find any information on them via the guide? Is this the corect part number for all four?

 

[Perry Babin]

That's only for one (Q2000) of the 4. The others are MJD44H11s

 

[rhempz01]

The voltage even drops at the center legs or the pad from 25v-19.6vdc when it happens?