Analog input noise fix on WebControl 8 board

[CAI_Support]

We have found that by reducing resistor R10 value, analog input noise can be significantly reduced.
The resistor R10 near the network socket which marked "472" is a 4.7K resistor. If solder on top that resistor another 4.7K resistor, most board's analog noise issue will be resolved. If the noise still exists after adding a 4.7K resistor on top, you can replace the R10 with a 2.2K resistor. Please make sure power is not connected when performing this fix.

All the boards currently shipping has this fix now. If you have difficulty to do this fix yourself, we will help you fix it. You can send your WebControl baord to us with return USPS shipping label in the box. We will fix it and then put your shipping label on box sending it back to you.

 

[edlentz]

Thanks, I am kinda handy with a soldering iron so I will take care of it. Although I am not using those inputs at the moment, it just looks bad to have them bouncing around.

Thanks again.

 

[rossw]

Can you share the part of the circuit that this R10 is in? How does lowering the resistance achieve more stability across all input channels? Not disputing it works, just like to understand what's happening.

 

[CAI_Support]

The Ethernet communication signals are directly generated from the processor itself. R10 too large will make Ethernet signal stronger. However, make it as low as 2.2K should still have normal level of Ethernet signal.

 

[TJF1960]

I have a rev 2.0.2 board purchased last year sometime. I just went to change R10 and found it was already loaded with a 2.2k resistor (2261 printed on the resistor). Was it originally 2.2k and was changed in a later rev?

 

[CAI_Support]

REV 2.0.2 board is older generation board, that does not have this problem.

 

[Machineman]

Just wanted to confirm this works. My A/I noise was lowered by adding parralel 4.7K to R10.

 

[CAI_Support]

Thanks for the confirmation.