Because it is a high-power, feature-dense device, internal components like the final amplifier transistors, PLL (Phase-Locked Loop) circuits, and microcontroller can drift out of spec or fail over time.
button while powering on to illuminate all display segments and the signal meter. Technical & Hardware Specifications TYT TH-9800 Driver FET Modifications | PDF - Scribd Tyt Th-9800 Service Manual Pdf
