kicker zx1500.1 output inductor?

[shane300zx]

Just repaired a zx1500.1 the irf3205's were blown and one 820uf 160v cap poped. Ordered new 3205's and pulled the bad cap for some testing and have 2.55 amps idle current but the problem is i hear a slight ringing in the output and the large output inductor is getting quite warm. Im kinda limited on my testing tools but do have a dvm. I played the amp at low power on 2 15"'s @4 ohm load and it got quite warm. on the terminals of the removed cap i measured 106vac.

Ant help guys half the battle is won it powers up and plays!

[shane300zx]

Tested the power supply gate resistors they come up all as 98.6 ohms. Im getting what sounds like an tube type am radio sound when i hold the test speaker close to my ear. Under power with a 6ohm load i get 100.6vac output.

[mike49504]

Did you replace the power supply drivers?? (drivers for the 3205's)

In theese amps its normal for the output filter inductor to get warm..

[Perry Babin]

Did the power supply side of the amp heat up quicker than the output transistors side of the amp when you ran it on the 15s?

If the noise wasn't clearly audible through the 15s, I wouldn't be concerned about it. If this amp doesn't have the oscillators synchronized between the power supply and audio sections, the noise may be normal.

[shane300zx]

Mike im not too sure about the power supply drivers or even where to locate them at. The heat sinks never get warm but like i said i dont have the last power supply cap in so i have not been beating on the amp. The only thing that gets warm is the large output inductor even at idle with no load hoked up to it. On a side note in you look at this link http://www.bcae1.com/temp/zx1500components.swf the fets to the left of the outputs i touched the case with the amp out of the case and got a nice shock!

[Perry Babin]

Those aren't FETs. They're rectifiers. You may not have any real problems with the amp. If the heatsink doesnt get warm, the power supply FETs are likely being driven properly.

Is the board discolored around the inductor?

Can you still hold you hand on the inductor after the amp has idled for about 15 minutes.

[shane300zx]

Ill have to test it i should be getting a cap tomorrow and puting it in. There is no discoloration around the inductor. Ill report back tomorow with results and should i have speakers hooked up to the amp without signal for idle testing?

[Perry Babin]

Speakers won't (shouldn't) make a difference. Only connect power/ground/remote.

[shane300zx]

So called around to local repair shops no luck on the cap. But fired it back up and after 15 mins of idle time i could only rest my fingers on the inductor about 5 seconds before it was too hot. Idle current remained at 2.33 amps. Had it at idle for around 45 mins and it was hot enough to not even think about touching it.

[Perry Babin]

I don't know what the idle current should be but since it didn't increase and none of the FETs get hot, the amp may be OK. The inductor can take a lot of heat. If you want it to run a bit cooler, install some thermal gap pad between the inductor and the cover of the amp.