I'm trying to troubleshoot my sister's new (used) mini. It's on 03 MCS with the H/K system. I've scoured the forums and spent the better part of a week trying to figure it out.

The HU powers up and looks functional - plays discs, tunes in stations - but there is no audio. I've taken the factory CD player out and it has a "Best Buy" sticker on the back . My guess is the previous owner had an aftermarket HU and when he sold the car had Best Buy reinstall the factory unit and screwed something up in the process.

All the connectors look unmolested. The factory harness is intact. I removed the rear interior to inspect the harness and the amp and everything looks as it should. There are two loose connectors in the rear harness but I didn't see anything to plug them into - maybe for an optional CD changer? We've purchased a replacement HU, but it does the same thing - power up, no audio.

The only think I can think of is if the amplifier is bad, but all this diagnosis by replacement business is getting expensive. Any way to test this theory?

I'm an Audio/Visual systems contractor by trade, so I know which end of the multimeter to hold. But this has got me stumped . Any help would be GREATLY appreciated.

Thanks!

 

Well, you wouldn't be the first person with a bad H/K amp, but the fact that Best Buy was mucking about with the stereo adds a whole new dimension to things. Also, the H/K amp is trés expensive, so I wouldn't replace it until you know it's the problem.

Have you identified the speaker wires coming out of the head unit? If you have, I'd put in a CD, turn up the volume and see if you get an AC voltage on the speaker wires. If you do, I'd check that there's an AC voltage where the speaker wires enter the H/K amp. Lastly, check and make sure the amplifier power wire is showing +12V and that there's little to no resistance between the amp ground wire and the car's chassis.

 

Gee whiz your quick!

I noticed when I turn up the volume ****, there is no visual indicator on the screen telling me what the volume is. Is this normal?

 

That's normal - there's no visual indicator of any sort for volume.

By swapping head units, you've pretty much narrowed the problem down to either the H/K amp or the interconnecting wiring. If your system had never been messed with up to this point, I would have bet money on the amp being bad. But since it appears that at the very least, the head unit has been swapped out, all bets are formally off.

Also, something else to think about once you get everything else working--Do both your original stereo and the replacement you got look the same? The later versions of the stereo from 2005 and 2006 have some additional capabilities compared to your original 2003 unit, so if your replacement is one of these newer versions, I'd keep it, even if it turns out that there's nothing wrong with your 2003 head unit.