Hello elektro-hobbiest, I have the same problem with my 3610D. Turns on fine, LED's work, fan spins, displays are on but sometimes I get no output from it at all. Other times it works fine.
I've noticed that the PCB is bent inside my unit, is yours bent? As comented here in this thread, it uses pretty standart ICs to work, current mode PWM controllers. First place to check is those as that is basically the brains of it.
I can never get mine to fail when i'm trying to fix it, so for now I'm checking solder joints of the components.
If you do find a schematic please post it
If I find something about this unit I will post back