LED flickering on first powerup of A12

[L-SCHLEGS]

what does this mean. the others i built have not done this.

where should i look to fix this? Thanks!

[L-SCHLEGS]

its makes everything flicker. even the light for the front of the chasis. the i have yet to put in the SC25 because the voltages are wrong.

help!

[L-SCHLEGS]

ok,
I figured out that it was the bulk filter capacitor C10. It was in backwards. So i unsoldered it and reinstalled it the right direction. Now the flickering is gone but I cannot get the B+ side to read the +14 volts. The B- side is working just fine.

So what do I do.

The B+ side reads -.36 at pin 4 and pin 3. Did I blow C10? or is there a piece after that that I blew.

HELP TIM!

I need replacement parts or whatever I need to fix this ASAP. Got to have this up and running by the end of the week.

[tpryan]

What voltage do you measure at the cathode (banded end) of D2?

What voltage do you measure at the cathode of D5?

[L-SCHLEGS]

30.5 at D2

and -.36 at D5

with the ground at pin 4 of U1

[tpryan]

What resistance do you measure between the cathode of D2 and the cathode of D4?

[L-SCHLEGS]

with the power off or on?

[L-SCHLEGS]

i cant get it to read anything either way. and my DMM squeels at me with the power on. haha

[L-SCHLEGS]

12.9K resistance from cathode of D4 with ground at pin 4 of U1 (with power off)

still nothing at D2

[tpryan]

You always measure resistance with the power off. What is the resistance between those two points?

[L-SCHLEGS]

between cathode of D2 and D4 there is no resistance.

[tpryan]

You mean there is zero resistance, or your meter doesn't give a reading? If the latter, you've damaged the board. There's probably a broken trace under C10. You can try to repair it with a jumper or send it back for a rebuild. If you do that, there's no way you're going to get it back by the end of the week.

[L-SCHLEGS]

well my DMM reads 1 when I touch the banded side of D2 to D4

so where would I run a jumper from underneath C10. to C11? I do believe that is the problem.

[L-SCHLEGS]

and you don't think I blew any parts? If I do a jumper I should be good? Let me know if you think that will fix it, if not, send me the info for the repair program so I can get a new one, cause either way, I will need to fix it, by the end of this week or not. Thanks for all the help! It was my stupid mistake.

[tpryan]

I'm still not clear on whether or not there is continuity between the cathodes of D2 and D4. You need to understand what your meter is telling you. If there is an open trace, it should be clear from the schematic where to run the jumper(s). If it's not, send an e-mail to rma@seventhcircleaudio.com for return instructions.