Originally posted by yellow15
so it's a faulty tx 
it looks like a software bug to me as the tx is working perfectly fine if i don't use the timer function.
Any way i can reset/anything else i can do as i bought the EX-10 from oversea and is a pain for me to send it back for check.
Send it back to where you purchased it from. If they are an authorized dealer, they can have it sent back for repairs for you. Or you can send it your self. I highly doubt that it is a software bug. If so, everyone would have the same problem. It could be some other component inside the radio that is failing and causing your problem. It is hard to say what exactly is the problem without having the radio to test.
Have you tried using a receiver battery connected to the recevier and use only servos? Not using the esc. Does the problem still happen? If it doesn't then, it's the esc.