Harley Benton MP-500 Interface/Foot Control

I found little info on these so I wanted to share some things others may find helpful especially if using bias fx mobile ios.
1) it is indeed pre-programmed for bias fx, but you will need to change the mode to bifx as the default is for jamup.
2) The ipad does power the pedal on its own, but you will need what apple calls a camera to usb adapter.
3) Adding external power to the pedal does not seem to charge ipad, (I am using apple USB 3 adapter) at least not with the apple adapter I bought.
4) The "L in" does send signal to both right (XLR and 1/4) and left (1/4) outputs. So you can xlr to mains and run a 1/4 out to an amplifier on stage. The output volumes are separate for these in mono which is nice.
5) There is some kind of funky bypass mode. (noted by a left arrow on led screen) Still not quite sure what combo of buttons I did that got rid of it.
6) The headphone out does seem to mute the other outputs when something is in it.
7) You can assign the positive grid tuner or a specific pedal to a switch 1-4, switches A-D are for your presets.

Not happy so far with product. I've spent over an hour tyring to get something out of it, but nothing. I've tried electric guitar and mandolin using 2 different patch cables, a condenser mic, and a dynamic mic. I've tried headphones with Garageband, and headphones with the unit not plugged into anything (except for power). So far, not a single indication of sound in any situation. No sound in the headphones, no sound in Garageband, no indication of sound on the unit's display.

The manual doesn't give any troubleshooting steps, so I'm fumbling in the dark, trying one thing and another, pressing buttons, turning dials, changing instruments and cables...

It shouldn't be this difficult.

Follow-up:
Still not happy with the pedal.

After several more hours of trying every combination of instrument/mic, cable, and app I could think of, I eventually discovered that I can get sound in and out of the pedal only if all volume knobs (on instrument, MP-500 input, iPad volume output, and MP500 headphone output) are set to 100%. But even then the volume is unacceptably low, and the volume can't compete with other apps. For example, I have an app whose free version I am testing before I buy the pro version, and it occasionally announces "This is the free version; please upgrade to pro". While I'm testing the MP-500 (with all volume knobs set to 100%), this announcement nearly blows my eardrums out because the output volumes are set so high.

Since I hear the announcement loud and clear through the headphones attached to the pedal, it seems that the problem is not with audio output from the iPad to the pedal. So the problem must lie in the audio being sent from the pedal to the iPad. But I don't know how to test or troubleshoot this.

Other problems:
-- The pedal gives no visual indicators of audio volumes. The only indicators are of knob position, not of actual volumes. For example, it doesn't really help me to know that the input volume on the pedal is set to +4dB if my instrument cable isn't plugged in properly or if the microphone is switched off. What would help is to see the actual audio level coming in or going out. The pedal shows a simple but nice display of the attached expression pedal CC values -- it would be great if there was such a display for audio as well.

-- The phantom power is only 24V, so if you have mics that require standard 48V phantom power, they won't work. (That was part of my initial difficulty -- I was using a 48V condenser mic for many of my initial tests. No wonder I couldn't hear anything. If the pedal had an indication of volume levels, as mentioned above, I could have seen that the mic input levels were too low, and I wouldn't have wasted time with that mic.)