STC 12C5205 (CB station command)

[blazzelia]

Hello,

I recently came into possession of a defective CB station, a MEGAWAT PRO-1000, which seems to be completely dead. Digging for the problem I got to the uC part - an STC 12C5205, which seems to be a universal uC.
On the pins where the crystal is connected, I have a clock frequency of 19.2MHz and on pins 9 and 15 (PWM) I have a rectangular signal of about 8KHz with a different fill factor. The signals disappear immediately after R815 and R816 respectively. Otherwise, all pins are 0 or 1, no other activity.
I checked all the voltages - they are ok. I checked the RESET and LVD pins and both have the correct levels after initialization (according to the uC data sheet).

I have attached the diagram of the station (please, a model with a different name but it is the same electronics).

Does anyone have an idea? Thank you,

D