repair for MCC USB-2416-4AO

[alexxxxxxac]

Hi all

I would like to ask if any have experience with repairing an instrument, MCC USB-2416-4AO.

The instrument is behaving funky with one of the channel is reading a voltage respond to two channels near by. It almost seems that there is a short on the board. Would like to ask if anyone is capable of fixing this instrument and this issue? Also wanted to know how much would that cost approximately. Thank you. 

 

Alex

[JRys]

The USB-2416 inputs are multiplexed, switching them one by one to the A/D converter. This style of design requires a low-impedance signal, while open inputs are high-impedance. If you have a channel connected to a voltage source and another channel that is not connected, the second channel can respond to the first. Connect the second channel to the device ground to eliminate any cross-talk. 

[alexxxxxxac]

Hi JRys

I appreciate your fast response on this. I would like too that there are also couple other issues with the board. Some other issues were the voltage not being able to get anywhere near 0 on the output channels. The temperature readings were also several degrees higher than they should be for room temperature indicating a need for calibration. The auto calibration with instacal didn't help for the inputs, and won't run for the outputs. For these issues, could this be some problem with the board? If so, my research lab would like to seek for some assistance fixing it. Thank you. 

 

Yours

Alex

[JRys]

An easy way to check the voltage output is to connect it to an analog input. For the measurement, set the input to single-ended mode. On my unit, I've connected VDAC0 to CH0H. When I set the output to zero, the measurement is approximately 1.2 mV. If your offset is much larger, the input can be checked by connecting it to GND instead of the voltage output. 

To verify thermocouple performance, a thermocouple calibrator is required to apply a known temperature. Configure the channel for Temperature with the Data Rate set to 60 Hz. Connect the thermocouple and let it and the unit warm up for 30 minutes. If you fail to let it warm up, or the Data Rate is set higher than 60 Hz, you can see errors of several degrees.

If you want us to do the testing, private message me with your contact information, order information, and device serial number, and someone will get back to you with the details.