I installed one of those door knox things from SytemQ a few weeks back to a new build. The thing is intermittently buzzing and of course the customer wont pay and System Q are hopeless.

I suspect the sparks have wired in my cable routes as i have even temporary lashed cables across the floor and everything appears OK. But its intermittent so how would i know. If i fail all the mains its clear but again i cant do a prolonged test so how do i know. 

I asked for a second kit on supply or return to prove kit but SQ are having none of it so ive purchased a second kit and the problem persist and im stuck with kit i dont want. BTW please dont tell me i shouldn't have bought from them. Hindsight isn't going to get me paid.

Anyone any experience in sorting this problem or even how to explain to the customer whats happening?

I once built a filter to cut everything below 75Hz on a car audio system might be an option

 

http://www.diyaudioandvideo.com/Tables/ButterworthCrossover/1stOrder/

intermittently buzzing at normal volume of just very low?

 

You can filter some bits with ferrite core/beads

1 hour ago, Nova-Security said:

You can filter some bits with ferrite core/beads

 

retro.... but +1

 

+ any unsed cores to 0v

 

alarmcon, when you used temp cables did you use the same psu ?

You get them with some Elmdene models

33 minutes ago, datadiffusion said:

You get them with some Elmdene models

 

seen 'em with psu's & internal EWD

 

however I was thinking per core-

 

 

pic from ACT

you have that many too?

Ah right, proper hardcore

5 minutes ago, james.wilson said:

you have that many too?

I've probably got beads on for single cores somewhere on stock, probably last used when enforcers where cream coloured & had no case screw

 

I've got split cores somewhere a telephone bloke gave me at least 16yrs ago...

so totally useless. a ce thing