Questions:
- Is there a detailed schematic I can use to troubleshoot/repair my Matrix?
- Does Matrix Labs do repairs or swap outs?
My Matrix Creator has worked well for a few months. Yesterday, I thought my battery went dead.
However, I believe it appeared as such due to a shorted component on the board downstream of the Matrix boards 3.3V regulator located at the top left as pictured below.
The bummer is that I am in the middle of an Element14 Presents video production showcasing the Matrix Creator when this happened.
I have been using it to drive an H-Bridge (L293D) with GPIO 0,2,4,6 and drive a servo with GPIO 1. I had not put any current limiting resistors in the Matrix GPIO and the H-Bridge as all tutorials omit them. The servo is powered by a 5V pin of the Matrix.
When I hook up a power source voltage/amp reader, this is what I see:
- My wall wart for this test is 5V @ 2.4A. I used two separate Raspberry Pi’s and got the same results.
- 5V supply is pulled lower to 4.4V when Matrix is installed
- 0.38A of just the Pi is raised to 2.8A when Matrix is installed. This is probably the max the wall wart can deliver and, to me, indicates a component is shorted.
- Pi won’t boot due to this under voltage condition.
- Matrix Onboard 3.3V regulator gets hot quickly.
- Matrix Onboard 3.3V regulator shows 2.86V where it should be 5V. My assessment is that there is a down stream short in the circuit that is pulling down the voltage.
- Matrix Onboard 3.3V regulator shows 2.11V where it should be 3.3V.
- Matrix Onboard 3.3V regulator shows no resistance to ground on its Vout (3.3V) pin. This to me tells me there is a short to ground downstream.
- Removed the Matrix Onboard Regutator and Voltage and Amps are fine with Matrix installed. This is most likely because I disabled the Matrix downstream circuitry by doing this.
- With the regulator removed, I still see no resistance to ground between the regulators 3.3V pad and the ground pad.
- When I substitute a battery source that can deliver higher amps, the Pi does boot, but the Matrix just flickers its front Blue LED and does not respond to code.
Thanks,
Sean