"RC Hardware" light: +5V failure

[P1h3r1e3d13]

The "RC Hardware" LED on our RC is solid "yellow" (it really looks like orange), indicating +5V low. We removed all our digital I/Os, made sure the pins were clean, then put our voltmeter to it and found out we had no voltage at all on the pins. We figure whatever internal voltage regulator the board has must be blown/fried/dead/[pick your own euphemism]. No magic smoke, but one person thinks the RC might be running a little hot.

Any ideas?

[Mike AA]

Originally Posted by P1h3r1e3d13

The "RC Hardware" LED on our RC is solid "yellow" (it really looks like orange), indicating +5V low. We removed all our digital I/Os, made sure the pins were clean, then put our voltmeter to it and found out we had no voltage at all on the pins. We figure whatever internal voltage regulator the board has must be blown/fried/dead/[pick your own euphemism]. No magic smoke, but one person thinks the RC might be running a little hot.

Any ideas?

Check your backup battery

-Mike

[KTorak]

Unless you removed all the Digital I/Os at once, you may have a short. We had this issue becuase our GTS was touching the transmission (sharp solder point went trhough electrical tape). Other than that....just check the basics and stuff for issues.

[P1h3r1e3d13]

Backup battery is fine (7.78 V no load) and we did remove all the digital I/Os at once. We were hoping it was a short, but testing the pins directly showed no voltage between the +5V and GND pins.

[Al Skierkiewicz]

The internal +5 volt regulator is self protected for over current and over temp. Usually letting it cool for fifteen to thirty minites will heal that problem. Then you must find the short on the +5 volt rail. Start by removing all inputs and outputs and then put them back one at a time while monitoring the +5. All will be revealed.

[bixbyrobotics1]

We are having the same problem with our RC, but even after a week with nothing connected to the RC we still get the error, and we desperately need the 5v!

[thefro526]

Omg we just had the same problem yesterday. After reading the manual I found out that there had to be a short somewhere in the wiring (thats what the light means). So a mentor and I pulled all the PWM cables out to try to find the short (if the light goes out the short is on that cable) but the cables were all find so I checked all of the male connections on the RC and one of the Analog outputs had a small metal shaving across it thus causing the short.

The light has nothing to do with the backup battery, if the backup batery was the issue then the light would light up on the OI. My suggestion to you would be turn your robot on and disable it. Then unplug each wire one by one. If the light goes off the problem is on the line. If they are not your problem then keep the robot on and disabled, get a toothpick or other thin object and run it between each pwm outputs/inputs. This should dislodge any thing that will short the outputs/inputs out.

[Gdeaver]

We had the same problem yesterday. It was a short on a switch.

[Al Skierkiewicz]

Originally Posted by bixbyrobotics1

We are having the same problem with our RC, but even after a week with nothing connected to the RC we still get the error, and we desperately need the 5v!

Bix,
Please examine the pins on your RC very closely and I bet you will find two that are touching. May have been damaged while someone was holding it.

[Qbranch]

You may also have managed to get chips in somewhere more... vulnerable. Two years ago in our 2006 robot, someone was drilling a hole right above our RC in our shooter's mounting bracket. The robot went to the field before anyone got a chance to get the vacuum... and during the course of the match a small aluminum chip managed to work its way underneath one of the LEDs in the top of the RC and into the protective plastic box that covers the top of the circuit board.

We later found out that the chip of aluminum soldered itself on with the initial arc when it hit the V+ and GND pins.

Moral of the story... always cover the RC and have a small vacuum cleaner handy!

-q

p.s. Since it's already broken as it sits, you may choose to void the warranty (which does not apply in this case anyways) on your controller and remove the four screws on the bottom that hold the top plastic cover on to expose the middle part of the PC board. There, look for the National semiconductor regulator (big power mosfet looking thing with heatsink) and see if your chip is there. If not, look around and i'm sure you'll find a short somewhere. Let us know here if you have further problems.

[P1h3r1e3d13]

So I'm sure you all need another anecdote, but two years ago, we were smart enough to drill/file/saw our aluminum frame with our electronics installed. ("It was just a little repair.")

We let the magic smoke out of three Victors and lost our +5V line (see my posts above). We found little metal shavings in everything, of course. We were able to replace the transistors in the Victors for a tiny fraction of the price of a new one, and if I remember, we got our RC ultrasonically cleaned and it worked. We also returned it under warranty later for some other reason.

But after all that, you can be sure we always removed our electronics or covered them in plastic before making metal shavings. I advise everyone to do the same.

[swalker92]

my advice is hook up an air sprayer to a compressor and unhook everything and just blow the heck out of it. we had a piece of metal so small you couldnt see it shorting ours

[Al Skierkiewicz]

I know a lot of people recommend using high pressure air to blow out debris, but I find that forces debris into areas you don't want it to be. Cover electronics and if needed use a vacuum to remove visible particles. The Victors are open on the top and closed on the bottom, so debris goes in but doesn't easily come back out.

[Mike Copioli]

I have a great one for you. Same problem only the aluminum chip was UNDERNEATH the analog header pins. It took me a few hours to find the problem. After replacing the 5volt reg and performing several tests I realized that there is a small space between the bottom of the header pins and the PCB. When the RC was held up to a light It was obvious that the there was something underneath the pins. The trick was getting it out. I ended up fishing it out with a stiff piece of wire.