So I think I have made a great error. My Robo 3d r1 plus was working find beside a fan that went out. I had to re-solder on the older connector of the broken fan to the new fan. I plugged in the fan to make sure it worked before I finalized the heat shrink tube and I am afraid I wasn't paying attention and the black and red connections connected. It shut down and would not turn back on (no fans not even the power supply). This is what I have tried so far: 1. I checked the fuse close to the power switch and it looked fine but looks can be deceiving. I replaced the fuse and the PSU comes on now (green light and fan) and the top board on the Arduino (which I believe is the ramp) blinks green twice and that about it. The red LED comes on the sd card reader. The fans are not working on any connections. LED strips on top are not coming on but they did on one of my trying flipping the switch. 2. I plugged in the Arduino to USB and the light stays solid green on the top board (which I believe is the ramp). #I pulled the Arduino off the bottom of the ramp and plugged in the Adruino into my computer via usb, it does show up in device manager and seems to boot fine. 3. Plugged Arduino back into the ramp, flipped the power switch and the Arduino has its green boot light but the ramps LEDs blick green twice. 4. Powered back on the machine, tried to use a multimeter (something I do not normally use) and I can't seem to get a reading anywhere. anywhere I would put it specifically? I am matching red to red and black to black touching multiple areas of the cables. PSU's fan is still running quietly with a green LED. * on second thought it seems my multimeter is broken will pick up another one tomorrow* 5. Purchased another multimeter and still can not get a reading anywhere on the PSU or the cables that link to the ramps board. 6. Tried Novice Expert's little trick to test if the unit is working by shifting the print bed back and forth to see if the LED's would come on and they did for a sec in the beginning. The Left LED has been going out for a while and was working intermittently before this issue. 7. Purchased PSU here https://www.amazon.com/gp/product/B01HEVGYWK/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 based on @mark tomlinson recomendation hopefully this will fix my issues. I will report back. any advice would be more than appreciated!