Harmon Kardon and water damage

[Vince Noir]

Evening all,

I have a 2016 BMW 4 series convertible (F33) which seems infamous for water leaks in the boot, especially where the HK amp (accessory code 688) sits. One day after particularly heavy rain I found no sound was coming from the car, not even the beeps and bongs from sensors or open doors.

I've checked as many fuses as I can identify, removed the somewhat junky Xtrons android unit and replaced with the original BMW screen - still no sound.

The HK amp is optical and I can still see a red and an orange light inside.

I've removed it and opened it up and it's nothing like as bad as some of the pictures I've seen online, although there is a tiny bit of deposit - see pics.

Has anyone had a go at repairing these at home?

I've read of folk dipping these in a vat of isopropyl alcohol and distilled water before cleaning off all the mineral deposits and corrosion. Sounds like a way I'd kill it completely though.

[Robertb]

I can't help you with a DIY repair, but Remanx might be worth a shout if you want to see if the unit can be repaired, as they do HK amps amongst other things.

[SteBrown91]

Also look at Cartronics (BM54.com)

[ethaan_7]

Water-damaged HK amps on the F33 are unfortunately very common, and even light moisture can be enough to kill them. If the optical loop is still lit, the head unit is likely fine, but the amp itself may have failed internally, often on the power or output stages. Home cleaning with isopropyl alcohol can sometimes remove residue, but it rarely restores full function unless corrosion is extremely minor, and there’s a real risk of making it worse. Most owners either send the amp to a specialist electronics repairer who can reflow or replace damaged components or replace it outright, then fix the root cause by clearing boot drain channels and improving sealing to prevent repeat failure.

[SitCet]

Be cautious around those capacitors.