Dishwasher Repair Nightmare: Chasing Down 3 Faults

February 5, 2023 by Donald Papp 41 Comments

It all started with a vague error code (shown in the image above) on [nophead]’s Bosch SMS88TW01G/01 dishwasher, and it touched off a months-long repair nightmare that even involved a logic analyzer. [nophead] is normally able to handily diagnose and repair electronic appliances, but this time he had no idea what he was in for.

Not many dishwashers require breaking out a logic analyzer and 3D-printed custom adapters, but this one did.

Not only were three separate and unrelated faults at play (one of them misrepresented as a communications error that caused a lot of head-scratching) but to top it all off, the machine is just not very repair-friendly. The Bosch device utilized components which are not easily accessible. In the end [nophead] prevailed, but it truly was a nightmare repair of the highest order. So what went wrong?

One error appears to have been due to a manufacturing problem. While reverse-engineering the electronics in the appliance, [nophead] noticed a surface-mounted transistor that looked crooked. It was loose to the touch and fell into pieces when he attempted to desolder it. This part was responsible for switching an optical sensor, so that was one problem solved.

Another issue was a “communications error”. This actually came down to ground leakage due to a corroded and faulty heater, and to say that it was a pain to access is an understatement. Accessing this part requires the machine to be turned upside down, because the only way to get to it is by removing the base of the dishwasher, which itself requires a bizarre series of awkward and unintuitive steps to remove. Oh, and prior to turning the machine upside down, one has to purge the sump pump, which required a 3D-printed adapter… and the list goes on.

And the E02 error code, the thing that started it all? This was solved early in troubleshooting by changing a resistor value by a tiny amount. [nophead] is perfectly aware that this fix makes no sense, but perhaps it was in fact related to the ground leakage problem caused by the corroded heater. It may return to haunt the future, but in the meantime, the machine seems happy.

It goes to show that even though every fault has a cause and a reason, sometimes they are far from clear or accessible, and the road to repair is just a long slog. Heck, even phones these days can be bricked by accidentally swapping a 1.3 mm screw for a 1.2 mm screw.

X-Carve, The Logical Upgrade To A Shapeoko

March 3, 2015 by Brian Benchoff 33 Comments

When it comes to small CNC carving machines for hackerspaces and extremely well-equipped garages, the Shapeoko, or something like it, has been the default machine. It’s dead simple – a Dremel attached to linear rails – and is useful for everything from milling PCBs to routing complex woodworking project to plotting designs with a pen. Now, [Bart Dring], the guy behind the Buildlog.net lasers and Inventables have teamed up to create the next generation of carving machines. It’s called the X-Carve, and while it’s fully compatible with the Shapeoko 2, it adds a few improvements that make for a much better machine.

The X-Carve does away with the Dremel-based spindle and replaces it with something that can produce torque. There’s a 24VDC spindle in the stock arrangement that will give you speed control through Gcode. There is, of course, adapters to fit the Dewalt and Bosch routers most commonly used in these types of machines.

As far as the gantry goes, the X and Y axes are makerslide; no change there. The Z axis leadscrew has an optional upgrade to Acme threaded rod, an improvement over the M8 threaded rod found in just about every other DIY machine kit. The entire machine is basically all the upgrades a Shapeoko should have, with stronger corners, NEMA 23 motors, and increased rigidity.

There are a few versions of the X-Carve, ranging from an upgrade kit to the Shapeoko 2 to a fully loaded kit with a square meter of machine space. The big, high-end kit ships for around $1250, but a smaller kit with 500mm rails, NEMA 17s, and threaded rod lead screw is available for around $800.

[Bart] and [Zach], the founder of Inventables sat down and shot a video going over all the features of the X-Carve. You can check that out below.

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