Fan induced noise, PG amp.

Anyone have a PG X1200.1 mono block that makes noise through the subs when the fan kicks on? It is a low level humm with a whine. It does not effect the performance which is quite good but it can be annoying knowing it is there. Just want to see if it normal before I send it back to them, thanks... Polo.
 
did it lways do this (like if it's a new amp), or did it just start doing this. It might not be a defect persay, just a problem in the design, but I wouldn't expect to find that in a PG amp.

I would suspect the fan and it's wiring. perhaps one of the decoupling capacitors around it is bad or has a bad solder? (most brushles DC fans should have a small electrolytic on their circuit boards)
 
Update.

Well against my better judgement, I cracked my new amp open (PG X1200.1) which can be seen under "Show me your guts", the amp seems to be built quite well. I got into it as far as to not break any seal dye but as soon as I removed the cover I knew something wasn't right. After removing the cover I reinstalled it back in the vehicle and started pounding on her. It took some time for the fan to kick on and when it did the noise was not there, hmmmm. I heated her up more to see if the noise would come back. I then turned down the volume (only way to hear it) and noticed it was there but was super low compared to what it was. When I had removed the cover I noticed that one of the inside isolating washers from one of the inputs were missing, or just not installed during manufacturing. The input was touching the case and some how amplifying the noise. I installed another washer, made sure all was isolated then ran her, the noise is so barely audible you need to have you ear against the subs to hear it. Something as stupid as a little piece of plastic, go figure... Polo..