Turns out, alcohol and phones don't mix. By referral, I received a message via Facebook about helping someone out with their wet phone. No other information was given. I met up with the customer and asked a few questions about the situation. Turns out a sugary cocktail was spilled on the phone. We're not talking about a splash either. The 4S was "dead", with the exception of the camera flash stuck in flashlight mode. It took a little while to remove the back panel on this 4S. It was held on tight by whatever sticky concoction had surrounded and penetrated the phone. Once the rear panel was off, a sticky mess presented itself on the battery and logic board. I could immediately tell this phone had been worked on before due to the foam pads missing on the LCD and digitizer flex connections - the screen had been replaced before. Removing the camera and logic board, if any doubt remained that someone had been tinkering around in there before, it was instantly stripped away by looking at the camera. There's a gold grounding clip that is secured to the logic board by a screw. This grounding clip makes contact with the camera's metal case. Someone apparently broke the screw hole off the grounding clip and decided to just tape it to the camera with electrical tape!!! (photo below) Who does that??? Someone who shouldn't be repairing phones, I would guess. The grounding clip is connected to ground by the screw, without the screw, it's just a piece of metal taped to a camera!
How crazy is that??
After removing the shields from the logic board and running it through the ultrasonic cleaner, rinsed, and dried, it fired right up! Photo on left shows the backlight glowing and on the right, the screen is attached by a test flex and there are two batteries because the one in the phone is the original and dead. Rather than remove it, I just placed a known good battery over it and plugged it in.
After removing the shields from the logic board and running it through the ultrasonic cleaner, rinsed, and dried, it fired right up! Photo on left shows the backlight glowing and on the right, the screen is attached by a test flex and there are two batteries because the one in the phone is the original and dead. Rather than remove it, I just placed a known good battery over it and plugged it in.