I accidentally shorted out the ground and +5 V supplies for the ADL5390-EVAL board. The result was a small spark, and now they are permanently shorted. I was hoping to find an obvious coupling capacitor that might have been busted, or a resistor that became low-resistance, but nothing is obvious. Is there advice on parts I could focus on to identify what part is broken? I hope to avoid having to altogether replace the board or the main ADL5390 chip.
Does it power up with approximately 135mA after shorting the supply to ground?
Upon power up, I would DC probe the baseband input pins to make sure the bias levels are correct. Baseband common-mode bias should be about 0.5V.
The +5 and ground lines are totally shorted, but if I power the board with a current-limited benchtop supply I also see nothing on the common mode bias source.
Oh, that's not good. I would start de-populating caps one by one, that are on the positive supply lines. After each cap is de-populated, I would Ohm the supply line to see if there is still a short.
If you de-populate every cap and there is still short, the part is probably damaged (short on-chip).