Flying C-130

I have been flying a Lockheed C-130, for several months with no problems. All of a sudden I can't control the the altitude it continues to climb until it stalls. I have tried both manually and with AP without success. I have trimmed nose down, I have dumped fuel, etc. nothing seems to work.
Any suggestions on how to fix this problem is appreciated.
Thanks one and all.
Dave
Any suggestions on how to fix this problem is appreciated.
Thanks one and all.
Dave