Any Robertson Audio 4010 owners on Agon?


I was wondering if I can get some help. I recently purchased this classic Robertson 4010, which works great. 
However, I have noticed that it gets really hot after two hours , even when it is on only and you are not sending any signal thru it, the blue power on/off switch gets really hot to touch, is that normal, or shall I take it to have it properly checked out by a certified tech?
I am hoping someone here would throw some light on this. 

Many Thanks

I've got one -love it It does run hot-dependant on what it's driving and how high its volume is. I can't be sure as its always been well behaved but Id get it checked it sounds too hot from my experience with my one. How hot are the heat sinks at the back? Even if it needs repairs its still great value for money. I've had mine for 30+ years and it still runs well. It used to drive my Linn Isobariks but now has now taken a backstage. What preamp are you using?
the 4010 does run physically hot, but if it has not been re-capped, it might be close to death. That would be a shame.
I Thank you both for your replies.
As I said in my post, the blue-lit on/off  switch is very hot, the top of the amp is not that bad. I am concern as to what is causing that switch to get so heated up?  
Secondly, how would you know it is time to change the caps, the amp sounds so good, you have to hear it for yourselves. None of the past amps sounded as good as this, that list includes, Adcom 555 II, McCormack DNA0.5, Levinson 431, Jeff Rowland 102.

 I am using an Advent 300 receiver as a preamp, and a pair of Gershman Acoustics X-1 speakers. 

No experience with your amp, but on a product that old, it likely has a bulb in the switch instead of an LED.  The bulb will generate heat.  Another possible factor is the switch circuit.  The switch might be wired to full current rather than a relay circuit.  That will also make the switch warm.
I too have a 4010. Presently in storage. Could be output stage bias drifting too high.

That is it, I am told by the original owner that amp has a bulb which generates lots of heat if left on for a long time.

Other then that, the amps sounds superb, super silent background,  smooth presentation, that perfect perfect detail, the tweeters "breath",  those bass notes that I thought never existed, that brilliant  control and timing of the musical notes, basically, all the musicians 'follow" the singer and play with him/her, my search for a power amp is over.

I would like to Thank once again to all of those who responded.