As I continue to work on used gas and/or electric dryers I am listing my guide that may be useful for others when repairing them prior to sale.
Check for sheet metal damage . Some areas of damage particularly in the top console area may hide a damaged switch .
Look at the power cord for damage. A damaged cord could lead to a short and a possible fire.
Remove the front cover noting any problem with the spring clips and fasteners.
Check the belt and remove it and the drum noting the orientation since some run the groove side against the drum and some run the smooth side against the drum. Turn the belt inside out to see if it is cracked.
Check the drum for problems at the front and rear edges for cracks or other problems including eccentricity. If the drum uses replaceable internal ribs remove one at a time and check for coins inside them and balls of lint. Reinstall and retorque the screws.
Take the rear drum support rollers off and check the roller support shaft for wear. The support for the drum roller located above the heater tube is most likely to be dry of lube and worn . The opposite side usually does not have this problem . Sometimes these can be switched but not always .Use a high temp lube but not very much. Most GE units use a single bearing support at the rear of the drum and most need replacement.
The idler pulley is possibly worn badly in the track for the belt and the bearing is usually in need of replacement. Some are seized .
The front cover on many units utilize two slipper shoes that may need replacement. There may be a cork layer underneath the teflon slippers and is also to be replaced .
Clean all the dirt and lint out of the lint trap area. Some are difficult to clean properly. GE units are very difficult to get the lint out from behind the perforated plate.
Check the door switch for proper operation and the door latch to make sure they are working correctly.
The wiring in and around the heating elements and also in the console area should be checked to see if connections are in decent condition and the terminals are not in danger of breaking, etc. On gas dryers the solenoids and glow bar should be checked for proper function and replaced as required
Clean all dirt and lint out of the burner area and vent pipe.
I may have missed something but these are the major areas I check for possible repair