Dynaudio 20XD amp module failure

Hi everyone,
I am seeking for help: One speaker in my Dynaudio 20XD has just died. Analysis pointed out that the amp module has failed, likely the amplifier IC as other functions like LED display, remote control still works, just no sound at all even I tried analog input port. This happened after one day its back panel got extremely hot, no smell or any sign of burning. The other speaker still works fine.

I have contacted a dealer but the cost for spare part is around 1.300 EUR which is terrifying (to me), more than half of the pair cost. The part number is 451302A

So I am asking if anyone has faced the same situation can give me some hints, or anyone happens to know the specific part number of the amp IC so that I can get it somewhere for replacement in my local repair shop.
Thank you very much!