Pixhawk receive no radio after firmware upgrade

I’m using pixhawk 1 and I haven’t upgrade firmware for a long time. I’ve mansion that pixhawk flashing yellow light after firmware upgrade is done. and I connect pixhawk with mission planner, I found that there is 8 zeros on Radio Calibration.
(Normally there are 8 1500 on Radio Calibration)
I google it for a week and I can’t find the solution.
What can I do/ diagnostic to slove this problem.

(sorry for my poor English)

what receiver are you using? some issues where noticed with Spectrum and I think this is now fixed in the new firmware.

I’m using TH9X + PPM Encoder as RC input , I’ve 2 set of receiver and pixhawk confirm the issue happened it caused by upgrade…