The tensioner pulley was off and the clips to hold it on were missing. I ordered and installed a new tensioner pulley. Although the dryer now worked it the drum was making loud noises when turning.
I called my daughter (her dryer) and was told the dryer had gotten increasingly noiser before it failed. I concluded that the drum rollers were bad probably caused the idler pully to come off.
In retrospect I probably should have ordered the repair kit which includes roller, tensioner pulley and a new belt. Anyhow, I ordered the kit