Hotpoint TDC60P NOT HEATING, HELP ME

I have a Hotpoint TDC60P tumble dryer. It was not getting hot so I purchased new thermostats from you and that cured the problem but then it stopped getting hot again about a week later. I noticed the dryer light was flickering, going on and off and when it was off if you hit the side it would go back on. I took the top and sides off, checked all connections, cleaned the inside and ran the machine, the light problem seems to have cured but still no heat. I have tested the elements with a multi meter and they seem fine – any suggestions, please.