DSL modem keeps restarting on its own

The last several days my DSL modem keeps restarting on its own, now several times per day. I've tried hard resetting it, resetting password and userid. There are no firmware updates as it's an old verizon modem. Is this a sign that it's dying?

 

Either the modem or the PSU is gonna give soon.

 

I was afraid of that. Thanks for the confirmation.

Edit: Well, I ended up trying it with another phone cable I had, after having the modem sit for a good 45 minutes with nothing plugged in, and it wasn't resetting. So far so good, I haven't had any resets.
I notice that when I hard reset the modem, I have to go in and click "detect wan configuration" every time, so the modem can properly detect the connection and configure itself. It resets itself and connects. I think it was just a bad phone cable, and must have intermittently cut off the signal, so the modem would reset itself automatically to detect the configuration. That's my theory anyway.
I'm glad I followed through with my hunch, but I honestly had no idea that a bad phone cable could cause that (I'm not experienced with networking stuff).
Just thought maybe someone might find this information useful some time.

 

Bad cable shouldn't cause reboots- modem would lose sync and try to establish it once again but not reboot unless the cable was causing some kind of a short-circuit.

 

Hahaha, forget it, it just rebooted on me. Dammit. I'm going to have to get another modem. Thanks for the insight downloads.

 

If your ISP is still verizon I would give them a call, I had a 6100 (non-wireless) I called and they shipped a new 7500 (wireless) for no charge.

 

That's exactly what I have actually. Though it's no longer verizon but another carrier that took over.