I have a White/Westinhouse dryer model DE/DG 650K. It makes a terrible screeching sound when running. The manual doesn't address any problems like this. I would appreciate any help with how to figure out what the cause of the noise is so I can better determine if it's worth fixing myself (keeping in mind I have no experience at this)/calling an appliance repairman or better to just buy a new dryer. Thanks!

I only looked at mine years ago. And a furnace. One suggestion is
Check the belt tension. That was my problem. Readjusted the tension belt.
It was loose. No.. I that's all I can suggest but an idea.

It is most likely a problem with the drum bearing. While it might be too much to ask someone with no experience to do this, an experienced DIYer can certainly do it. The parts should cost around $20-30.

Here is a video that shows the basic procedure, although it may not apply exactly to your dryer.

Best of luck in what you decide to do.
WallyH

If you are fairly good with mechanical things it is very easy to fix a drier. Just look on YouTube. Make sure and clean the drier well when you take it apart and always put in a new belt, unless it has one already. You probably need a new bearing kit and easy-to-follow directions are on YouTube. Just unplug the drier and take out to your garage so you have plenty of space and remove all parts and clean them while you have it apart, including the blower fan. Should be no problem at all. DrTom4444

Once you take it apart you will be able to see what is causing the screeching. It could be that a piece of felt is missing around the end of the drum causing it to ride metal to metal. That is a common cause.