R7800: hissing noise from adapter

[microchip]

I have the R7800 router a few days in my possession, but just today I noticed a hissing sound coming from its adapter while plugged in. It is not loud and you have to go close to it, like 15-20 centimeters, to hear it. Otherwise, the unit is operating normal

Anyone has the same issue?

 

[microchip]

found the issue. it's the adapter of my switch, plugged in right next to the one of the R7800.

 

[e38BimmerFN]

Tend to do this when not built right or a sign of going bad sometimes.

 

[TonyH]

I have the R7800 router a few days in my possession, but just today I noticed a hissing sound coming from its adapter while plugged in. It is not loud and you have to go close to it, like 15-20 centimeters, to hear it. Otherwise, the unit is operating normal

Anyone has the same issue?

If you are talking about wall wart(AC power adapter), being a switching type it can make audible noise when not in perfect condition or of poor quality. Could be early warning sign of going bad. Is it original adapter? I've been using R7800 since it first came out. Don't have that symptom. If you have an o'scope, you can look at the output.

 

[microchip]

It's the adapter of my little 8-port switch. I changed it with another (has a slightly higher Amp, 0.6A for original while the new has 0.85A max - both same voltage of 9V). The noise is gone completely. I thought initially it was the router's adapter but I was mistaken when investigating more closely (both adapters are right next to each other)

 

[avtella]

Could be a bad capacitor, interestingly some models I think my D7800 or R7500v2 had a similar whine due to the capacitors which was actually normal, that was the router itself in that case.