** Kenmore Electronic 90 Series dryer that's all digital and about 10 years old **
I'm afraid that is not enough information to identify the appliance in question. What is needed is its exact model number ("90 Series" isn't it). If you post it we can at least look it up to see what appliance design you're dealing with to try to answer your question.
You can find tips for locating the model and serial number identification tag on your appliances at the following link:
** I don't have the manual and can't find it online. **
Once you get the appliance's complete model number you can find owner's manual resources in the 'Home Service' section of my web site linked below. It however will not usually give other than the very most basic of fixes (eg. is the appliance plugged in, etc.). It is NOT a service manual so don't expect it to help with most repair problems.