It began with a imprecise error code (proven within the picture above) on [nophead]’s Bosch SMS88TW01G/01 dishwasher, and it touched off a months-long restore nightmare that even concerned a logic analyzer. [nophead] is generally capable of handily diagnose and restore digital home equipment, however this time he had no concept what he was in for.

Not solely have been three separate and unrelated faults at play (certainly one of them misrepresented as a communications error that triggered numerous head-scratching) however to high all of it off, the machine is simply not very repair-friendly. The Bosch system utilized elements which aren’t simply accessible. Ultimately [nophead] prevailed, however it really was a nightmare restore of the best order. So what went mistaken?

One error seems to have been on account of a producing downside. Whereas reverse-engineering the electronics within the equipment, [nophead] seen a surface-mounted transistor that regarded crooked. It was free to the contact and fell into items when he tried to desolder it. This half was answerable for switching an optical sensor, in order that was one downside solved.

One other difficulty was a “communications error”. This really got here all the way down to floor leakage on account of a corroded and defective heater, and to say that it was a ache to entry is an understatement. Accessing this half requires the machine to be turned the wrong way up, as a result of the one approach to get to it’s by eradicating the bottom of the dishwasher, which itself requires a weird collection of awkward and unintuitive steps to take away. Oh, and previous to turning the machine the wrong way up, one has to purge the sump pump, which required a 3D-printed adapter… and the record goes on.

And the E02 error code, the factor that began all of it? This was solved early in troubleshooting by altering a resistor worth by a tiny quantity. [nophead] is completely conscious that this repair is unnecessary, however maybe it was the truth is associated to the bottom leakage downside attributable to the corroded heater. It might return to hang-out the long run, however within the meantime, the machine appears comfortable.

It goes to point out that despite the fact that each fault has a trigger and a purpose, typically they’re removed from clear or accessible, and the highway to restore is only a lengthy slog. Heck, even telephones nowadays may be bricked by by accident swapping a 1.3 mm screw for a 1.2 mm screw.