Hi Rudy, I hated the thought of trashing such a useful instrument so I gave it another try. This time I disconnected the plugs going to the solar panels and added an external power supply in parallel with the internal battery and It has been working on the bench for days. When I disconnect the external power supply, the instrument remained powered from the internal battery overnight without any significant drain. Now that I am confident the unit is able to function, I will add a solar panel. The solar panel has an onboard regulator to keep the output at 5V to the USB jack. Here are the Amazon ASIN’s: B0DF7PZ4TT, B0F9XGF24D
