rockford fosgate BD1500 stopped working

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left side output FETs reads
-4.6V with the protect LED on and off

right side output FETs reads
-4.6V when protect LED is on
when the protect LED goes of it quickly spikes to +9v then goes to about 4.5V then 1.5V and stays there

waiting on your input for now not to make any wrong moves!
 
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blowing fuses ? if i use a 10A fuse of course since its pulling about 10A at startup,
its just enough to make it tick!! that is why i used a 15A fuse and monitored how much it was pulling with the DMM... this morning with the battery fully charged
its pulling 9A all of the time that the AMPmeter is inline with B+ and the protect LED never goes off when the DMM is inline.. but it does go OFF when the AMPmeter is not present

with a 15A fuse it doesnt blow but its still pulling 9A at idle
with the battery fully charged and the charger still on the battery i have 13.8V between B+ and GND terminal of the amp and when the remote is connected it drops to 8.3V yet again.. even with the battery fully charged

the power supply FETs are getting mildly warm thats about it ... not that much!!
I would say that they are probably not supposed to get that hot at IDLE, but that they are well enough under reasonable operating range if the amp would be working...
I just dont know if they are supposed to get a bit warm even at idle.

I dont know if it is producing audio since i know there is something wrong i did not try to look at that because when i measure voltages at the output FETs gates.. the readings SUCK real bad... and the black probe was on the negative terminal of the AMP for all of the measurements i am telling you

the left side output FETs reads about -5.3V on them and stays there even when the protect LED goes off
and the right side output FETs reads -4.6V when the protect LED is ON and the reading goes a bit random when it goes out... some times i read +2 ish and stays in the 1.5V range.. some other time it spikes at 8V then immediately goes to +2V and moves around at 1.5V 2V
then i try to confirm the voltages for you... and recheck the output fet so i check one and boom +10V when remoting the amp instead of around +5V and the protect LED wasnt going out... and i recheked 2 or 3 times and the readings were more normal around +5v with the PROTECT LED on... but it never came off those 3 times...

there is definitely something weird going on...
I think there is something wrong with the voltage regulation dont you think ?
if i read from +4.5 +5.5 even sometimes +10V on the output FETs with the LED ON and sometimes -8V -5V -2V -1V with the LED OFF??
 
The battery is either too small or defective. The amp is designed to go into protect mode at about 8.5v. You need to get a better 12v power source before you can do any more troubleshooting.

When measuring the DC voltage on the outputs, you have to place the red probe on the gate and the black probe on the source.
 
not looking to contest you here but i have tried 2 fully working batteries and 1 snapon booster pack (wich is a battery with huge CCA ratings) and they all do EXACTLY the same thing... 12.5V-13.2V without remote and 8V-8.5V with the remote connected....
something in the amp must be pulling hard ...
 
allright i think i found the 8.5V problem
as i said tried with 2 different batteries and a booster pack and now with 2 diferent DMM with all the same results
but i tought..
I had a retractable test leads thing (12-16awg) with 3 cables and crocrodile ends on them.. i was using this for testing purposes since it made my life easier.. however i was thinking with all that length of wire etc maybe its acting as a kind of resistor fasling the results... so i hooked up the amp b+ and gnd terminal directly to the battery with the big wires.. and used the crocrodile only for the remote ... and now even a 20A fuse blows.. so i think the amp is pulling MAD power and this is why the battery voltage was reading that low...
what do you want me to do ... now that we know the amp pulls at least 20A .. disconect the bid red/black HV twisted wires and then what ?
 
now dissoldering...
the caps are not charge... since yesterday everytime i try to discharge the caps as a safety measure... nothing happens as if they were not charge... something in the circuit must not be going to them... or maybe the amp as a safety measure doesnt charge them... I will let you know the results with the big twisted wires disconnected...
only the pair that goes to the output stage like seankane said.. LMK if i should remove the other one also...
 
I have remove the right side long twisted pairs.. from the bottom of the amp (power supply side) wich are labeled +HV and -HV on the board, they are the ones that goes near the output FETs
the left side twisted pairs are still connected...

i have one DMM in ampmeter mode and one in voltmode ... when i connect the remote the ampmeter reads 19A so i unhooked the remote imediately and i didnt even check the volt reading but from the corner of the eye its not dropping (wich was probably caused by my long small crocrodile wires) so the voltage problem and batterypower source problem is fixed..
anyways
amp is pulling 19A right now
 
sorry for the last 2 days poor diagnostics... with the crocrodile wires making some false readings... if you had known it was pulling 20A from the begining i am shure you would have known where to guide me quicker...
I will know for the last time... no small long wires... (duh.. or course)
 
updates for you guys
while i was waiting for Perry to answer.. i decided to remove the LEFT side twisted wires.. guess what.. now i power the amp.. pulls 2.2amps .. protect LED goes off after 1.5 seconds as it was a week ago when the power supply side was working fine...
there is something wrong with the left side twisted pair
 
the left twisted pair connects to the 3 caps on the left and on all of the output FETs drain side HV+ and HV- that passes through the FB1-FB16 (what are those by the way ? some kind of fuses ??)
I finally figured out that BOTH twisted wire pairs are connected together on the PCB so i needed to remove both of them...
 
when looking closer at the PCB to see where HV+ and HV- leads... i noticed the 2 C41 connections are blacked out as if they had shorted together... but i never discharged them there.. i always used the same spot on the left side ... so if they are blacked out.. and i didnt touched them.. they probably shorted together somewhere WITHOUT any resistor or headlight attached .. could this arm the cap or something around it... making both HV+ and HV- shorted together ??
 
when i measure at the caps i get around 8k and rising/falling when i set the DMM to 20K
and around 50K and rising/falling when i set the DMM to 200K
the difference is probably caused by where i set the DMM to ... what do you think ?
anyways none of the caps reads real low as shorted...
 
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