A1706 MacBook Pro: Probe Point Corrosion Kills SSD Detection

Why It Fails in the Same Spot Every Time

Water enters through the keyboard or vent intake and flows across the logic board to the same corner where a probe point sits on the V2.7 NAND power rail. The probe point has a gold-plated top surface that resists corrosion, but the copper trace running underneath the solder resist does not. The copper corrodes, the trace disintegrates, and the NAND chip stops receiving power. The Mac boots, finds no storage, and shows the question mark folder.

The probe point can look intact from above. The corrosion happens underneath the resist layer. You need magnification and a test probe to check the edges and corners. If the copper has crumbled away under the surface, the trace is gone even though the gold pad looks fine.

The Repair

Once identified, the fix is a jumper wire bypass: solder a small wire from a good PPBUS source directly to the buck converter input, routing around the corroded trace. Alternatively, if corrosion is localized, scrape away the solder resist, remove the dead copper, and re-route with a 0.25mm jumper wire. If R9350 or nearby capacitors also corroded, those get replaced too.

After repair, V2.7 should measure stable at the NAND chip power pad. If the SSD shows up in Disk Utility, the fix worked. In most of these cases the data is fully intact because the NAND itself is sealed and resistant to liquid damage. The storage wasn't broken; the board just couldn't talk to it.

The lesson for technicians: on any liquid-damaged A1706, check the probe points first. They fail before everything else. Many hours get wasted replacing capacitors and resistors when the real problem is a corroded trace under a probe point that looks fine from the top.