A customer sent me his Analogue Systems RS-290 Sampler-Delay module for repair.
This module has a DIP header for power and had the wrong power applied. In addition someone had attempted repairs by replacing a number of resistors with 1/2W 2R7 resistors and in the process lifting or destroying pads and runs. I was able to get email help from Analogue Systems to determine the right value resistors to replace. Why anyone would replace random resistors with 2.7R is just bizarre.
The wrong power had fried U4, a CS4223 Cirrus Logic 24 bit audio codec, so I replace it. Other parts were probably protected by the 3.3V regulator. U4 is a 28L SSOP with 0.65mm pitch. I hand soldered it but did not have enough magnification to verify my soldering. I took it to a local company with a surface mount workstation and with proper magnification determined it needed just a bit of touch-up (two pins that appear bridged in the photo below are actually connected on a single pad). This fine of pitch is just a bit beyond my hand abilities.
With these repairs power consumption dropped significantly and the module again operates. This module is a bit complicated so I let the customer do a full check-out saving me time and them money.
I also made a power adapter cable to adapt this to Eurorack. I used a shrouded Eurorack header and sealed the pins with epoxy. This module draws a lot of power so I used two wires per voltage.