sunroof drain flap was stuck closed = lots of water in trunk

i didn't notice anything until i turned my speakers off by pressing the left volume button in.

then when i went to turn the sound system back on i got nothing
so i poped the trunk to check fuses and found water in trunk over the fuses on R side, and over cd changer on L side

fuses for audio all good

the left button doesn't turn the system on anymore
gps works fine = no sound

when i press menu the DSP options don't come up and when i go to settings it has 4'1/2 written on the top right

how do i isolate my dsp amp as the problem??? so i can get around to finding a replacement and fixing this issue

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04 black on sapphire 4.8is personally put 90,000kms
fully loaded minus the fold out trunk floor
-20' DUB X10 3 piece rims staggered setup
-LED angel eyes + interior lights + e70 style shifter
-AFE stage 2 intake system
-x-pipe/resonator delete
-UV coat windshield
-rebuilt Pano roof
-dynavin N6
-all front and rear end suspension parts and both front cv shafts replaced
-OEM hitch

And 2007 GSXR750