Fuse Blowing Out - GTO 52.

Dear all,
I am having a trouble with my GTO-52 1 colour.
Last friday, the gto was printing good and all.
On Saturday, upon turning on the main switch, no lights whatsoever was on.
Taking apart the main power box and testing all fuses, Fuse F7/L3 was blown out and replaced it today, the machine turned on but main motor is running nor inching. The fuse F7/L3 blew again (3 times) when powering on the machine without any button press, disconnected all main motor wires, its back up again. Could it be the motor having problems or some circuitry?
Attached picture of the power box.
Greatly appreciate some help!

 

Hi sir:
Test the push button for continuity in the ramal of F7/L3, since one of them must be in short circuit.
By the reason when you push some button, the Fuse, is blew.

When you turn on the machine, and you Do not press any button, the motor Run well, that is mean the motor is o.k

2) Otherwise the Q2 WILL BE OFF.

in Short test all the push button, according with the schematic diagram

 

Hi sir,
I mistyped. Motor is not running. Sent it to a local workshop. Awaiting their feedback before continuing.

 

Please test , without motor Turn ON the machine

And press any button , and see , IF there FUSE f7/L3 is blowing?

You will have a Good idea, if some button is short circuit, or electronic board.

 

Dear Chock,
Motors are all ok after testing.
Fuse F7/L3 still blowing without any button press upon powering on the main switch.
Disconnected all the wires in the electronic board but no improvement...
Regards.

 

Hi sir;

You must disconect the Main Trafo, the secondary.

And see if the F7/L3 is blowing.

If Not blowing, you, must test the 15L1 inductors +Filter
+Q2 +KLM + HSK what happen.

See after you disconnect each componenet , the fuses is blowing, when you connect again each one.

Use my technic a Inandescent Bulb 100wats in Parallel with the FUSE F7/L3, if the Bulb is Brillant, is signal that short is there ,and IF is NOT brillant and goes OFF the short is NOT there.