Problem - No "Parking Detection" (PDC) Beeping sound from ALP system

[modsl55amg]

I have two cars which recently had STiR Plus systems installed. One car also had an ALP Quad w/HiFi and GPS installed. The other had an ALP Quint w/HiFi and GPS installed. Both cars had the correct, most recently released 4 files downloaded, by me, to the ALP systems, with the correct ALP Control Box serial number contained in the appropriate Uxxxxxxx.bin for each car. Testing each car's PDC sensitivity and operation was performed using a white sheet of paper. All sensors on both cars alerted with the appropriate red blinking light, as well as with a beeping sound. As the white sheet of paper was moved closer to each sensor, the frequency of the red light and beeping sound increased. All good so far.

I then downloaded a flash drive with different SETUP selections, in order to see if I may like them as compared to the original SETUP settings. The EXACT same flash drive was inserted into the USB port of the ALP system in each car. I did not immediately notice a specific difference until a day or two later.

The car with the ALP Quint has the red light flashing and a BEEPING sound, increasing in frequency as the white sheet of paper is moved closer to each sensor.

However, the car with the ALP Quad has the red light flashing, increasing in frequency as the white sheet of paper is moved closer to each sensor, but now THERE IS NO BEEPING SOUND being emitted. The voice audio for the Programming Functions, using the ALP Control Unit buttons, is being emitted correctly.

I have since downloaded new and different SETUP selections on various flash drives. I have downloaded the EXACT SAME SETUP selections, from the EXACT SAME FLASH DRIVE into both systems, but there is still no PDC Beeping sound being emitted by the car with the ALP Quad system.

Does anyone have any idea of what the problem may be, or how I can get the PDC Beeping sounds to once again be emitted from the car with the ALP Quad system?

Thanks in advance for any ideas, thoughts, suggestions.

[BestRadarDetectors]

Press the power button with a quick press to turn the parking sensors back on. You probably turned them off by accident when pressing the Power button. Short press turns parking on and off and a long press turns the unit on and off.

[modsl55amg]

Press the power button with a quick press to turn the parking sensors back on. You probably turned them off by accident when pressing the Power button. Short press turns parking on and off and a long press turns the unit on and off.

TM/BRD.....That was it! I just read your reply, went to my car, turned the ALP system on, let it stabilize, then quick pressed the Power button....and on came the beeping! Success! Thanks for your quick reply and solving my "problem". I appreciate your help! All other features/settings working great. Now waiting for my first LIDAR encounter and/or testing session here in S.J.