Dead pen?

I have a rather elderly Intuous PTH-650 tablet. It was working fine for years, but now the pen has been leaving soft, fuzzy & semi-transparent lines instead of solid ones. 

I spoke with Intuous support who said the tablet & pen were out of date and advised me to purchase a new model. (However, when I use the table and pen on 3D Paint it works fine.)  

The Wacom app Table Properties says "The tablet driver is not reponding...if turning your computer off and back on doesn't work, contact Customer Support" and the Desktop Center says "no device connected," even though I've been using it for years. (It also says the driver is up to date - 6.3.46-2)

I'm using Photoshop 26.2.0 on a Windows 10 64 bit desktop. A driver check told me "errors found. to resolve the errors try the following: Restart the drivers or contact support" but I've already spoken to support.

Any advice out there? It just feels like there should be a simple repair (or pen replacement?) here rather than buying an entirely new tablet. Thanx in advance!