Hi Perry
Sorry to bother you again
But im having problems with this amp again....
Ive installed it into the car recently. Its been sitting since i fixed it last as the car was off the road.
Basically Ive installed it into the car and it worked for about 2 days and blew the fuse in the power cable. Because im running two amps i then had to change the power cable to a bigger amp rating so it could handle the increase in power draw. But now the power indicator is flashing red and then the amp started getting hot. The other lights (protection and music) were green and the music one was blinking so i guess that means theres no internal problem according to the error codes in the manual. But i still dont know why its not working.
Please could you help
Sorry to bump an old thread.
thanks in advance
Sorry to bother you again
But im having problems with this amp again....
Ive installed it into the car recently. Its been sitting since i fixed it last as the car was off the road.
Basically Ive installed it into the car and it worked for about 2 days and blew the fuse in the power cable. Because im running two amps i then had to change the power cable to a bigger amp rating so it could handle the increase in power draw. But now the power indicator is flashing red and then the amp started getting hot. The other lights (protection and music) were green and the music one was blinking so i guess that means theres no internal problem according to the error codes in the manual. But i still dont know why its not working.
Please could you help
Sorry to bump an old thread.
thanks in advance
I haven't checked them yet. I'll pull it out of the car and open it up and report back
Is there any reason why it would do this as it worked fine for two days besides being powered by a smaller cable at the time?
Is there any reason why it would do this as it worked fine for two days besides being powered by a smaller cable at the time?
Okay I checked the output transistors and between transistor Q505 to Q508 were showing 0 ohms on the meter between legs 2 and 3. I then measured between legs 1 -2 again to see if any showed lower than the rest and Q506 did show a lower resistance. So took that one out and powered up the amp but without any rca's connected etc and the amp powered up fine. Power and music lights were green but the protection light was blinking red, is that because there was no rca's connected right?
Should i replace all the fets in that section or can i get away with just replacing the one? Its the IRF540N transistor.
thank you
Should i replace all the fets in that section or can i get away with just replacing the one? Its the IRF540N transistor.
thank you
At the very least, you should replace all of the IRF540s in that channel.
These are the error codes:
http://www.bcae1.com/temp/1507errorcodes01.gif
These are the error codes:
http://www.bcae1.com/temp/1507errorcodes01.gif
okay ill order some and get those fitted
Should i check anything else before i order the fets?
The error codes show that the protection light blinking red means RCA ground floated. I had the amp powered from a 12v car battery on my work bench so did not have any RCA's connected. I remember you saying in a past post that not having the RCA cable connected shows this error aswell?
Should i check anything else before i order the fets?
The error codes show that the protection light blinking red means RCA ground floated. I had the amp powered from a 12v car battery on my work bench so did not have any RCA's connected. I remember you saying in a past post that not having the RCA cable connected shows this error aswell?
If it produces clean audio with the shorted IRF540 out of the circuit, the only problems that I can think to look for is a gate resistor that's out of tolerance.
In some amps (Rockford, mainly), the IRF540N isn't a good choice. The IRF540N is the OEM part in the 1507 so it's what's I'd normally recommend but if they fail again, I'd suggest using either the IRF540A or the IRF540 (no 'N' suffix).
In some amps (Rockford, mainly), the IRF540N isn't a good choice. The IRF540N is the OEM part in the 1507 so it's what's I'd normally recommend but if they fail again, I'd suggest using either the IRF540A or the IRF540 (no 'N' suffix).
okay ill wire it up into the car without the shorted IRF540N connected and check if it works properly. Should i use a 15amp fuse in the Battery positive? Its just that my current 4 awg power cable has a AFS type fuse and to use a 15 amp fuse ill have to use a thinner power cable as it has the correct fuse holder for the 15amp fuse but then i wont be able to turn the volume up too much to test it.
How can i check the gate resistor and where abouts on the board is it?
thank you
How can i check the gate resistor and where abouts on the board is it?
thank you
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The transistors must be clamped tightly to the heatsink so if you're going to play it (at a low level or into a light load, only), you may have to place the shorted transistor under the clamp so it will hold down the remaining, good transistor.
The gate resistors are the 33 ohm resistors connected to the gate leg of each of the output transistors.
The gate resistors are the 33 ohm resistors connected to the gate leg of each of the output transistors.
Ive checked resistors R515, R513, R511, R509 and they show 33 ohms on the lowest setting on the meter. Are these the right ones to check?
Q506 is driven by R511. That's the one most likely to have failed when Q506 shorted. It appears to be OK.
okay i replaced all the IRF540N's in the channel that was showing one faulty.
I then wired it up using a 10 amp fuse as i did not have any 15 amp fuses. The amp powered up fine with all lights showing green. I kept the volume at 2 on the headunit as anything higher was making the power light flash red sometimes. It ran like this for about 15 minutes. I could feel the amp going warm on the output side but not hot like last time. I was trying to check if the sub was moving at all and I dont think it was so i adjusted the gain and the LP filter a little as they were on the lowest setting but then the amp just started getting hotter on the output side and then the power light started flashing red like last time.
Checked the transistors i just replaced and now Q507 was showing to be blown. So ive taken it out and now im back to square one again!
Could there be something else causing this problem?
thanks
I then wired it up using a 10 amp fuse as i did not have any 15 amp fuses. The amp powered up fine with all lights showing green. I kept the volume at 2 on the headunit as anything higher was making the power light flash red sometimes. It ran like this for about 15 minutes. I could feel the amp going warm on the output side but not hot like last time. I was trying to check if the sub was moving at all and I dont think it was so i adjusted the gain and the LP filter a little as they were on the lowest setting but then the amp just started getting hotter on the output side and then the power light started flashing red like last time.
Checked the transistors i just replaced and now Q507 was showing to be blown. So ive taken it out and now im back to square one again!
Could there be something else causing this problem?
thanks
forgot to add.
The 10 amp fuse did not blow instead it just melted the plastic around it but the fuse did not blow.
The 10 amp fuse did not blow instead it just melted the plastic around it but the fuse did not blow.
It sounds like the bias may be set too high. What area of the heatsink began to heat up first (under which transistors)?
The heatsink was warm around both output channels sides and then when it started getting hot it was mainly Q508-Q505 transistor area. Thats where now Q507 has blown.
What is the bias? I remember you telling me to set VR601 and VR602 to show 49.5v which i did and they havent been adjusted since the last time i fixed it and it was working.
What is the bias? I remember you telling me to set VR601 and VR602 to show 49.5v which i did and they havent been adjusted since the last time i fixed it and it was working.
With one meter probe on test point 1 and the other meter probe on test point 2, what is the DC voltage?
You need to be as precise as possible. No input signal and no speakers connected.
You need to be as precise as possible. No input signal and no speakers connected.
okay ive just checked that and it was not showing anything. The meter stayed on zero. I also tried with another meter and that showed the same. I also checked test point 3 and test point 4 and that was the same.
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