It started soon after upgrading to MPVI2. I would plug it in to OBD2 port and get nothing, no lights, no nothing, or sometimes the lights would flash every few seconds, sequentially from BT, HOST OBD to PWR, real fast, and repeat every few seconds. After about 1 or 2 minutes of doing this, the green PWR light would come on, and usb would finally detect and everything would work. It did this to me on a few vehicles, and on my bench harness.
I contact HP Tuners, pretty much no other questions asked after telling them this they replaced my MVPI2, the process was pretty quick, expressed it to them, they expressed it back. No explanation of what was wrong, and no reply to my email asking what was wrong with it.
Not long after I started getting same issues again on the replacement MPVI2. This time I was thinking no way two with similar issues. I changed which USB port on laptop I used, new cable, but yet, still have the same issue, or similar. Now the lights will blink sequentially from BT to PWR but very fast, 3 times a second like a strobe. Let it do this for a few minutes, and finally the PWR light comes on solid and usb hooks up. Yesterday I read 3 vehicles, added credits, and synced, and went to write, and hp tuners had lost communication with the mpvi2, looked at the obd2 port and it had started flashing the lights right after the sync. After 1 or 2 minutes, light was solid green again and the vehicle flashed fine.
here is what the first mpvi2 did: https://youtu.be/eYDV7vLzoeI
and here is what the second mpvi2 is doing: https://youtu.be/Ea_w_4xtq8s