You should have a red dot on the front of the machine,if the main processor is running at least.If not,you need to investigate the 5 volt supply there.Nothing else will function if the 5 v supply is missing.

Nick

Hi Nick 

5 v supply is present on pin 1 of P7 connector so I'll reassemble PSU on deck and check again if there's a red dot on the front of the machine.

Many thanks

MArco

Hi

Display show sign of life and LM317 become warmer after few minutes, I must investigate and replace it also.

Have a nice weekend all.

MArco

The 10 ohm safety resistor that burns up in the power supply,is in the 14v supply line to the deck motor.It usually blows because the motor has seized due to the belts perishing and tangling up the mechanism.

There is a safety circuit that monitors the 14v supply,and if it's too low,eg due to jammed mech ,the main processor is inhibitied,so no functions are available.

Is your mech jammed?Disconnect the motor to see if the machine then fires up without it?Obviously the mech won't run,but there should be some activity when pressing buttons.

Nick

Hi Nick

My mech isn't jammed, I've disconnect the motor before took the pic, although motor run well if I power up with a battery...

Have a nice day

Marco

Pin 16 of IC1,the processor,is the 5v supply there.

Check for dry joints where the ribbon cable from the keyboard connects to the main board too.

Check the reset network TR26/C33

Otherwise,I think you will have to check for activity on the various in/out ports of the processor,but it could be faulty.

I have a spare salvaged part for this if you need it?

Nick

Thank you for suggestions Nick 

Good afternoon 

MArco

Hi Nick

check voltage on pin 16, 3,90 volts,  but watching on schematic Vcc (5V) should be on pin 40, I'll check tomorrow.

Have a nice afternoon

MArco

Sorry,yes you are correct it is pin 40.I think I need new glasses?

Nick