Macbeth TD903 Transmission Densitometer

Description

I purchased this used but in good working order just to do black and white film readings. I have moved with it a couple of times now. Its been treated with care in moving and stored in my house. I am just getting around to finally building a darkroom but recently discovered this one is not working. It turns on, zeros but doesn't read / nothing changes on the display. I found another densitometer so I will sell this one for parts, hopefully you can fix it and have a nice unit.
I have throughly and accurately described the item's history and condition. It is sold as is.