MSM 430 Radio Performance

[swu30]

I have a mix of MSM 410 and MSM 430 APs running in autonomous mode. Initially we were all 410s. I bought a few 430s to try out, with the dual band radios being the big draw. I configured the 430s as identical as possible to the 410s, exceptions with the added features/capabilities of the 430. 

The radios were set the same on the 2.4GHz side, and accordingly on the 5GHz side. I mounted the 430s in the exact same location, same mount, as the 410 they were replacing.  Right away, looking at the client connections on the 430s, I noticed much higher (worse) S/N numbers on the 2.4 side ( -70 db vs -50s db) and 5.0 numbers that looked horrible (-80 db +). Like wise, end users were commenting on how slow, balky their connections were.

I have looked through the configs comparing the radio settings with 410s that were still up and running. I have turned off the 5.0 radio just to see if that was adding to the poor performance on the 2.4 side. Not the case. The Noise level IS higher on the 430s, for being in the exact same location, so that does contribute to the worse S/N ratio.

Am I missing something in the config or placement of the 430s? Are they that different? I am running both the 5.5.3 and 5.7.2 firmware. 

In a few locations I have resorted to re-installing the 410s. 2.4 only, but the performance is so much better.

Any help would be greatly appreciated. Thanks!

[JoshQ]

I have the exact same issue except that my AP's are a bit different. I have mainly 560's throughout and they work fantastic. The 5 430's I have can't support more than a handful of clients before it becomes unusable. Out of my 40 AP's only those 5 have issues with connectivity and supposed inteference, but when you place a 560 in the room there is no interference or connectivity. 

At this point I have noticed that only the 430's have excessive RX FCS errors, multiple retries, and single retries. The 560's have none. This is in the middle of the night with no clients connected you can watch those increase. Tested cabling by using another cable, moved AP to another location and had the same issue in a room with no issues. This is directly related to the 430's, but I have no idea why. Best guess I have is that they are interfeering with themselves since on the radio 2 page has no packets counted but only thousands of RX FCS errors.