Philips Hifi Amp Mux- how to tell activated

[JackoJuaquo]

Hi,

Recently bought a C5 from a very nice gentleman, he told me the original RT4 head unit had been replaced in the past year due to water ingress, however he disputes the water- the rusting on certain elements behind the dash say otherwise!
The issue I’m having is the front speakers are all mid and low, the tweeters don’t seem to be getting any signal. Tested tweeters and they’re working fine. Got me thinking it’s the amp as the head unit is definitely putting out high fqs as the rear set of speakers is fine.
I have no diagbox- Lexia to check if the new head unit has had the multiplex amp activated. Is there a way to know? Should I have more detailed EQ control on the Headunit if it was activated? I have LR, FR, bass, treble, nothing for sub. Amp seems ok, no water damage, as do cable looms.
Hoping someone has experienced similar! Thanks

[Kees]

If mux is not activated, then not all of the speakers working, so, you have to find someone to do the proper activation with the diagbox.

[JackoJuaquo]

Thanks for the reply. I’ll try that, makes sense

[SterkeYerke]

Not sure about the EQ control as my 607 doesn't have a muxed amp, but you can indeed activate it via either Diagbox or Mirascript if I'm not mistaken.