Its almost certain that the turntable requires a total recapping. All of the electrolytics are old and out of spec. This will display a variety of symptoms including problems with the tonearm.
Until you recap the turntable, you will not have any idea if something more needs to be repaired. If you continue to use a 20+ year old turntable you will eventually burn out something that is very hard to find a replacement for.
Denon used, what are now, very hard to find controller chips (ASICs, microprocessors, etc) in their design. If you burn these up due to shorted/open electrolytic caps, you will have to throw away your turntables.
I'm not saying this because I dislike Denon turntables. I have owned one since 1983. I took excellent care of the table and in 2010 it requires a complete recap job. There isn't an "if', "and" or "but" that will change anything. If you want to have a vintage Denon turntable, that is a reliable turntable, you have to invest in a total recap of the electronics.
Seeking out and replacing a cap here or there is a waste of time. You will just get another problem in a short amount of time. If you are handy with a soldering iron its not hard to do. If you are not, any qualified technician can do the job for you.
My old Denon is a DP-62L. The total amount of caps was somewhere around 40 (I can't remember, it was 2010). The total parts cost was less than $40 USD. If you can do the soldering, there isn't much of an argument to not do the job.
If you do not do the recapping job, there isn't much reason to complain around here.
It won't Help or change the reason why your turntable is not working.
PS. Since my old DP-62L has been recapped it is back to being rock solid dependable. It will likely outlive me.