XWave Pro c300 car audio

[MarkoM]

Hello,
I have problem with XWave Pro c300 car audio (cd/usb/mmc).
It wont turn on. Standby current is about 50mA.
On/off button, on front panel, is red, but no reaction when I press it.
Electrolytic capatitor had white emulsion all over it, and I changed, but nothing happends.
Earlier this problem sometimes appears, and with one punch was solved, but after last punch it is dead.
What should I check?
Thanks!