I am currently working at a lego robotics camp, and one of our RCXs has been malfunctioning. Everytime you want to download a prograqm to it, it asks you to download the firmware again, and never actually downloads the program. Does anyone know whats wrong with it???:eek:
I would try a different computer. If that doesn’t work, take the batteries out, let the 5 second memory storage go dead, put the batteries back in, and then try the firmware. That’s about all I can come up with.
I’ve had this issue many times. After spending some time on the phone with Lego tech support, I was told to remove the batteries, then press the power button at least 50 times. I’ve never had that fail.
what version of programming are you using? for me, the fastest way (using the lego mindstorms software) is to turn the RCX on in front of the IR tower, go into RCX settings on your computer (or something like that) and theres a button to download the firmware to the RCX
I do believe that when i asked one time, they said 50 million times. (jk)
It has been my experience that this problem occurs in one of two ways. The battery compartment has a series of contacts that become pushed back into the case. With the batteries in place and the cover off, if you turn the RCX over and shake it and a few batteries fall out, then you know which contacts need to be aligned. The second problem has been that the firmware has been corrupted during the load process. This is usually caused by interference with the IR tower during the load. Placing a box or an open notebook over the RCX and IR tower during firmware load will usually cure this problem. Remember that firmware takes at least four minutes to complete. Also check that the battery in the IR tower (non-USB versions) is fully charged.
on a side note, i grew up in elementary school using the RCX, i have an RIS 2.0 in my room, and now i feel extremely old seeing kids in gr5, gr6 playing with the NXT…i feel so old, and i’m only going into gr 12…lol
Hey now, don’t feel so bad. I still swear to my self that my RCX can do anything that an NXT can do, only better! 
But setiously though, the NXT marks a transition for lego as the left the brick shape of the RCX and moved into the Technic bricks.
thanks, that seems to be our problem, is there any easy way to re align them?
Very carefully, using a small flat blade screwdriver, you can gently pry the contacts out until they firmly contact the battery posts. You might also want to clean them with a little denatured alcohol and a q-tip.
What is taking place is the small current required to keep the processor happy is not enough to overcome the high resistance of the bent contacts. So although everything appears to be fine, the processor thinks it has a dead battery. The higher current for the motors, reduces the voltage drop across the bad contact(s).
If you can remove the battery case, you will get a better look at the contacts and where to bend them and on occassion I have found a cracked solder joint. Loose contacts are a sure sign of a dropped RCX.