500 V2A Power supply High Pitch Noise 8

[sfcstroud]

thread940-1817625 spoke directly to high frequency noise produced by PSU in the new 500 V2A chassis. Our company just encountered this problem. We were able to swap a working power supply into the chassis to provide immediate relief to the customer but wanted to figure out where the problem was. After taking the case off, using a pencil eraser I started probing components for a change in amplitude or frequency. There is blue disc capacitor marked C3. When I touched this capacitor, the noise lowered significantly. I bent it over about 15 degrees and 75 percent of the noise is gone. There is also what appears to be another device emitting a similar, but much lower amplitude sound located on board labeled VR1. I will be applying some high temp sealant to both of these to permanently stop the oscillation. Hoping this helps someone.

 

[Westi]

thanks for that tip. Get some pink for it and it will help for sure. I still hear it but in a few years my hearing will be so far diminished that I can't hear it any more hahaha

All joking aside that is a great tip and keeping that part cool might be all that is needed.

Joe
FHandw, ACSS, ACIS

https://www.millsidetc.com/

 

[BFG9K]

Glad I wasn't the only one that noticed this, and cheers for the tip!

Cheers,
BFG9K
Avaya IPO/ACCS Technician
Melbourne, Australia