Quote:
Originally Posted by MarkFromCA
I've checked and re-checked for cracked joints around the a-board power areas. I've rechecked my solder job on the c-board. I'm honestly not sure where to go from here.
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If resoldering the joints on the neck board led to the issue then one of two things is true. Either you dropped a solder blob somewhere when you were doing the reflow, or there was a problem that was always there and it only showed up after you did the reflow. If it's a solder blob, it could be anywhere below the area you were working on. If it's a preexisting condition, then it could be either a short or a wrong/missing voltage.
Since your B+ is missing, that's good information. That's something you can trace out.
first thing to do though is to check for shorts across the rails. There shouldn't be any really low resistances between ground and any of the power source points. If you see anything that's like 10 ohms or less, be very suspicious. Really anything lower than hundreds of ohms is a little suspicious on any of the rails, and you would want to verify that on the schematics.
If you find a short, figure out what's shorted.
You can also trace power from the plug all the way down the line and see where is disappears. That's important to do, but it's likely that there's something amiss somewhere further down the circuit as well if one of the main power rectification parts is blown. For example, if the main power transistor is blown, that was probably a result of something else.