Display turned 90 degrees and strange colors
This could well be because of a wrong type of controller. The display needs to have an ILI9341 controller but your display probably has a ST7789 controller. The displays look exactly alike so you can not tell them apart.
Microphone not working
If you have an external microphone socket, chances are the switch in the socket is the culprit. Place a jackplug and remove it to break and make the switch. (you can uses the headphone connector, but best is to turn off the detector first).
If you are in the building process, check that solder jumpers SJ1and SJ2 are closed of the external mick socket is in place.
Furthermore the microphone has no moisture protection so keep it dry!
Battery not charging
The battery can not be charged via the micro USB connector on the right side of the detector, (next to the headphone connector) that port can power the detector and is used for software updates/debugging but not for charging.
Use the port located on the short side facing the operator.
USB-C to USB-C cables and smart chargers could give problems detecting the device. USB-A to USB-C (or micro USB) all work just fine.
(charging a drained 8000mAh battery can take over 8 hours)
Headphones not working
When you have a detector with a separate audioboard, be sure to use a stereo headphone (3 conductor RTS) and no 4-conductor (TRRS) jackplug headset with microphone. (Teensy4.1 bases board v0.7 can be used with TRRS connector)
Messed up settings
If you accidentally changed a setting and do not know how to restore it, restore to default settings by holding the left pushbutton and power-on the detector.
GPS not working
GPS is a bit tricky, the reception is less than on a navigation device, it is recommend to first acquire a fix by using the GPS settings page. In the settings page alle high speed data signals in the detector are off and GPS data is read every second. You should get a fix in 50 seconds or less.
Bootlogo stays in the screen (partially) and button functions show NULL
The probably is due to an error related to the temperature sensor. If the sensor is broken, or not present this happens. Please update to software without the temperature sensor, of (re)place the sensor.