Quick fix for DC electronic load?

[crashintoty]

I picked up a new Kunkin KL283 DC dual channel electronic load device (https://www.ebay.com/itm/30A-Dual-Channel-DC-Electronic-Load-Adjustable-digital-LED-display-KL283-Adapter/371958986412). Channel 2 of this device works just fine, but for some reason channel 1 always shows a voltage of 2.56 despite no power source or leads connected to it. If I attached any power source to it (battery or bench power supply) channel 1 then reads 156.08 volts no matter what the actual voltage of the source (3.2, 3.7, 5, 12, 24, etc. volts). Turning on a load does nothing - the voltage doesn't change from 156.08.

Returning/exchanging this would mean a week or more turn around, but I don't want to wait that long. I'm not an expert, but I'm very comfortable tinkering with/fixing electronics - based on the description of the problem can you suggest any quick fixes or diagnostic methods for troubleshooting the mysterious voltage readings on channel 1 and getting it to work/properly draw current?

[TheMG]

Since you always get the exact same two voltage numbers, I would suspect a fault somewhere in the digital realm. Could be a defective ADC or bad communication between the MCU and ADC.

You could confirm this by measuring the voltage that is present at the ADC input pin for that channel, and see if it varies according to the load voltage.