Jolida 502BRC turning off uncontrollably

Just randomly tonight my amp will not continue to stay on. The red standby light is light, then I'll hit the power switch and it will blink as usual and once it's warmed up the light then switches to blue.

However, after a couple minutes or so, I'll hear a loud pop through the speakers and the amp will be back in standby mode. The first time this happened, it smelled a lot like burning electronics...great.

Now it doesn't smell at all but the problem still persists. I checked all the tubes and nothing is loose and rolling around in any of them. All the red lights beside the power tubes are red indicating that the bias is correct. I don't have any tools to check beyond this but how would I go about doing this a different way? I no longer have the manual and I've tried to get another from Jolida but no one ever responds to me.

Aside from replacing the tubes, or paying someone $120 locally to go over it, what would you suggest?
Given the info in your post, you clearly have a big problem somewhere. You need to take the amp out of the system immediately. Since it smelled like it was burning, the only sensible thing to do would be to have a professional check it out. Also, if you have access to another amp, it would be a good idea to put it into your system and do some listening just to be sure nothing else is damaged.
Had a Jolida1000RC that did the same was the crappy J.J. Tesla tubes I used to replace the stock ones...problem solved when I reinserted the stock tubes
If it has JJ Teslas, remove them ASAP...they are crap.