RCX 2.0 Firmware downloaded successfully but "Run" does nothing

Question

I recently was able to install RIS 2.0 for the first time since I just got a 32bit Windows 7 machine.

I got the IR tower to download the firmware to the RCX 2.0 and it showed exactly the same screens the guide showed, but when I got to the point where I test the motors, I found that the "Run" button does nothing.

I tried installing the firmware 3-4 times and still have the same problem, so I'm assuming the RCX itself has a defective Run button.

Does anyone know what's possibly going on? All the other buttons work, they beep and change the screen when pressed, nothing beeps or happens when Run is pressed.

Answer 1

Could be the button indeed. These buttons are conductive rubber pressing on the circuit boards integrated contacts. Might need some cleaning there...

Disassembly of the RCX is not easy but can be done. You have to remove the screws in the battery compartment, then pull slightly to disengage and remove the black IR front. Once this is done, you can pull out the PCB and battery case from the top cover. Important note: the PCB is connected to the battery case through metallic blades that can easily bend and no longer make contact. So when you pull the PCB+case, you must pull on the PCB itself, not on the battery case.

Once done, you can clean the button area with alcohol and/or swap buttons to hopefully repair the Run button ("View" button is useful, but not mandatory...).

Answer 2

Two things spring immediately to mind:

1. Are the motor cables connected properly?
2. Have you uploaded an actual program to the brick?

There is at least one way to connect the cables, at either end, such that the motors will not work. For this test, make sure the cable wires go out toward the "back" of the brick and the motor.

And, AFAIR, "Run" doesn't do anything with the motors unless you have uploaded a program that actually turns the motors on. I'm no longer familiar with the shipped software, so I don't recall if the process you describe actually does more than upload a firmware.

So, ensure that you are actually putting a program on the brick that turns the output(s) on, and those specific outputs are actually connected to a motor in the correct manner.

My quick test is usually to use the IR remote to tell the brick to enable A, B, or C outputs in either direction. You can also use the lamp to test; if the lamp lights then the output is on, and will also drive a motor.

Also, if you press the View button a few times, it will show a cursor next to an input or output. If the IR remote or program toggles an I/O, you will see the display change to indicate the state of that I/O.

(I see that I missed a key point: the Run button does not beep or change the display. This indeed points at a hardware problem, and not a config issue as I discuss here. If so, a quick-ish solution might be to get some of that contact cleaner stuff ["CRC QD Electronic Cleaner"], pull the batteries and squirt a little of that into the spaces around the button.)