Electrical: GR 3770 Not Powering Up.

[DAG COPIERS & COMPUTERS]

Background info: The machine is run on a petrol generator, no problem. Now it doesn't power up, completely dead. Panel blank, no anything, no nothing.I made preliminary checks on the power supply unit..ohmeter checks, the major protective components intact. At the back side with the rear cover off, you can observe those numerous LEDS flicker briefly as you toggle the main power switch and then they go off. Substituting the switching mode power supply unit would be the best method in this case inorder to quickly eliminate it as a suspect, but I don't have one.If any one has passed through a similar fire before, I'd be glad to hear from him. Thanks in advance.

[Iowatech]

First the stupid stuff, because it has burned me before and I can't see the machine. Double check the the power cord is seated properly at both the outlet it is plugged into and also the machine.
Also, make sure the output from the generator is OK and the generator has a proper load (For what it is worth, I learned in the Reserves that if a generator doesn't have a suitable load it probably won't work that well, but I've only actually seen that in action once with a diesel powered 100KW generator that was running at less than twenty percent capacity (I think actually less than 5% capacity, but that was a while back so I'm not sure).).
If all that is OK, check the 5VDC supply, the logic circuits need that to function, and it kind of sounds like that isn't working. You should be able to monitor that on power supply fuse 9 with a meter. If the fuse is good but not the voltage, that probably means the power supply is bad. Otherwise, make sure connector 5 is OK on the power supply board, as well as I think connector 7 on the main board and the wiring between them and the 5VDC input to the main board. If that's OK the main board could be bad.
Hopefully there's something you can use in this. Sorry for all the generator stuff.

[DAG COPIERS & COMPUTERS]

Thanks iowatec for your reply. It makes a lot of sense. First, the generator's output is good, since there's another riso fr3910 also being powered by it and its working well. I'll have to really crosscheck the condition of the output terminals of the extension socket in use, actually I had some doubt about it .I'll also have to do a thorough troubleshooting of the power supply board in question. That will be work for the next time. Machine is in neighbouring country, I must organize to go there again. I'll keep you informed of the progress of the work. May I take this opportunity to thank you for your new avatar; the dog in the picture exactly resemble my male dog in both color and appearance. Very very fierce dog.