JL Audio 500/1 Rev. 10

[hifonics hugh]

Q600-Q607 were all burnt . R600-R607 were all within tolerance with the exception of 605 being burnt.

Q600-Q607 Are IRFZ44N's. Is there a suitable substitue? After I put new ones in what should be my next step; other that replacing R605?

[Perry Babin]

The originals work perfectly fine. I've used Z46s in a lot of them and those seem to work without problems.

You'll need to check the output transistors to see if they're shorted.

When you reinstall it, make sure that you use the proper fuse. JL Recommends a 50 amp.

[hifonics hugh]

Perry once I cut all the z44n's away I measured .69V across the middle legs so I think the transistors are fine. It wont hurt to replace them though. The surface mount resistors(r605) maily where can I get them?

Thanks
Hugh

[Perry Babin]

With the black probe on ground and the red probe on the gate legs of the FETs, do you read ~5v DC about 15 seconds after the amp is powered up?

[hifonics hugh]

yes all are approx 5 volts with the exception of q605 and im sure that coz there is no r 605 green led lights up too. Looks good so far.

[Perry Babin]

If it doesn't have any shorted output transistors, all you may need to do is replace the out of tolerance resistor and the power supply FETs.