PS02 pin 1 2.7v

[RafitaTB]

after some hours of tracking , i noticed the power on ligth dimmed also the ligths on the a12 , no smell , it is'nt hot . i was tracking with a N72 , and no problems , so i decided to open and measure the rails so i have

pin 1 +2.7v
pin 2 0v
pin 3 -27v
pin 4 0v
pin 5 47.3v
pin 6 0v

when i begin the session the power ligth was ok

thank's

[tpryan]

If you disconnect the modules from the supply, do the rail voltages return to normal?

[RafitaTB]

yep , i disconnect the modules , and voltages return to normal , just when i connect the A12 module ( the one that i fried the sc25 ) , make that sympton.

i t was working ok yesterday. , no smell , no smoke , just pin 1 of ps02 2.7 v

what do i look for?

thank's

[tpryan]

What happens if you connect the A12 but remove the SC25?

[RafitaTB]

ok , i remove the sc25 , conect the a12 module , still 2.7 on pin 1

the sc25 is a new one that i bougth with another a12 module (2 sc25)

it was working ok , till some hours of tracking i realize that the power ligth was dimmed

thank's

[tpryan]

Could be a shorted bypass capacitor. Is the positive regulator (U2) hot? If so, try removing C4 and see if the voltage returns to normal.

[RafitaTB]

didn't have the chance to pull the module out , but i did check it with the multimeter and C4 is shorted .


thank's