missing leds on one c4s board

[Doc B]

I just saved myself $600 yesterday by reflowing about 20 solder pads that looked perfect in the fuel injection control module on my truck, rather than replacing it with new or rebuilt one. Went from no cold start to firing right up on the first try. A reflow very often solves the problem.

 

[jagmeetbatth]

ok will reflow all three boards

 

[jagmeetbatth]

reflowed all three boards.connected back again
no change.
what is supposed to bring down pin 20 and 30 to 145 .
is it something in circuit not working

 

[Paul Birkeland]

what is supposed to bring down pin 20 and 30 to 145 .

When the 6C45P tubes conduct, they will pull that voltage down.  The high voltage at OA/OB on the center PC board and the high voltage on the OB terminals on the high current C4S boards tell us that the 6C45P tubes are unable to do so. 

One thing that is common to both tubes is the ground connection from the attenuator to the ground bus line.  It's certainly possible that the black wire leaving the attenuator isn't well soldered on one end.

 

[Doc B]

Since this kit uses the Teflon insulated wire it is also worth checking for breaks in the wire just inside the insulation where the wire might have been nicked when it was stripped. We see that issue every so often.

 

[jagmeetbatth]

i havetested connectectivity of all ground wires and to all point where they go.
i am 100% sure its not the issue with any dry joints
what are the chances of tubes being faulty.
is there any way to test

 

[Paul Birkeland]

The odds are very, very low that you received two dead 6C45P tubes.  You could certainly purchase another pair to rule that out though.