Rockford Fosgate 1500-1bd (2007)

[Perry Babin]

19v is still enough for all of those regulators to do their job.

If all waveforms were good before reinstalling the rectifiers, you could have a defective inductor. It's rare but I don't see anything else that could be causing excessive current draw.

 

[rhempz01]

Two of my outputs are heating up perry if I let it run enough they were 100°f. I had good drive signals.

 

[Perry Babin]

What are the circuit board designations for the two heating up?

 

[rhempz01]

Q2014-2011

 

[rhempz01]

Pulled and tested the transistors and they are good. And amplifier Powers up normally now.

 

[Perry Babin]

Are those still heating up?

What do you mean by 'normally now'?

 

[rhempz01]

Yes, they are removed from the board. Looking for the problem on the output board.

 

[Perry Babin]

I think this may be a common issue. I spoke to someone else who had this problem and I also had this problem. The amps I've worked on worked as they should, survived the burn-in testing and haven't had any problems after being reinstalled up by the owners.

 

[rhempz01]

What I meant perry is it only is working normal without the two transistors that we're heating up so there is an issue with those two mosfets. With the other transistors still in At leg 1 I have -89.6vdc and leg2 0vdc leg 3 -91.4vdc. so there must be a problem on the output driver boards somewhere. Would I need to remove all the output transistors and check for drive again on those two locations?

 

[Perry Babin]

It cannot possibly work normally without those transistors in the circuit.

Why do you see those voltages as being wrong?

 

[rhempz01]

Ok so if I go around the output transistors now on diode setting red on 1 and black on 3.
Q2009-2007 .667vdc
Q2008-2006 open
Q2015-q2013 .006vdc
Q2014-q2011 open

 

[rhempz01]

What I meant by normally is the chirping and flashing of current draw stopped. It's as if a drive is intermediately shorting..

 

[Perry Babin]

0.006v looks like a dead short. Defective drivers on main board?

 

[rhempz01]

Would it be any chips perry or is that unlikely. And I found one that is reading a short 1Q is that the same as a 1am..?

 

[Perry Babin]

No.Look at the top of the semiconductor datasheets page. There are a couple of sites for SMD codes. The second one generally has the datasheets as well. I don't know for certain how sensitive the circuit is to subs and don't have any known good subs.

 

[rhempz01]

I am perry. The issue is it's been repaired and has several different types of transitors. I would like to know what was originally used on the board. I beleive that mmbt3904-mmbt3906 will work. Just unsure.

 

[Perry Babin]

What's the circuit board designation for the transistor in question?

 

[rhempz01]

Q20, q1, Q8 there are quite a few I'm unsure of perry. Is there a photo of the board in the guide or a schematic of this driver board?

 

[Perry Babin]

What board are these on? Rockford part number on board, if there is one.