70 volt speaker wiring diagram

[frg000]

Hello, i'm new at this forum, i recently took over a 70 volt installation, i have been troubleshooting without any luck a section of speakers that are generating some weird noise almost static noise out of one channel of the amp (on all sources), the system has three sources, a mixer, and amplifier, out of the amp i have volume controls AT 35W and at the speaker taps is set to 10w the amp is 200w amp total and there are 9 speakers setup in channel 2 and is divided in two zones by 2 AT 35W, at this point I find myself lost, so before i change the amp and mixer i wonder if anyone would have some input on how to troubleshoot a noisy row of speakers, i would appreciate any responses thank you.

 

[frg000]

update to my problem, after going over all the speaker wires and connections i found bunch of areas where the cable was damaged by staples so after isolating these areas, speakers are running smoothly thanks for reading