# I reversed gnd and vin... **URL:** \ **Category:** IDE 1.x\ **Created:** [May 17, 2014, 1:31pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305 "2014-05-17T13:31:16Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 17, 2014, 1:31pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305/1 "2014-05-17T13:31:16Z")
I've connected the gnd to 7.2v and the pin vin to the minus of the battery... as result the chip near the DC power connector blow up! Ok... now I have two questions 1-Which is the name of the chip? There's written something like 113nf 2-Is that chip the only thing I broke? I'm so afraid T\_T ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 17, 2014, 1:51pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305/2 "2014-05-17T13:51:21Z")
I'm using an arduino UNO r3 🤤 ---
**Author:** ![CrossRoads](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/crossroads/32/214033_2.png) [@CrossRoads](https://forum.arduino.cc/u/CrossRoads)\ **Post date:** [May 17, 2014, 4:38pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305/3 "2014-05-17T16:38:17Z")
Post a picture. I find this works well: copy from the product page, paste into powerpoint, draw an arrow, save as .jpg. Then clickk Additional Options, Browse to your file, and Attach it. ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 17, 2014, 4:45pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305/4 "2014-05-17T16:45:58Z")
> CrossRoads: > Post a picture. Thanks for your reply, I hope to find a solution in order to not buy another arduino 😃 There are 4 arrows in the left-bottom corner ![arduino1.jpg](https://europe1.discourse-cdn.com/arduino/original/4X/a/7/e/a7ec8954ead00cb4425a2fd4ed670ad3f0bb7ae3.jpeg) ---
**Author:** ![retrolefty](https://avatars.discourse-cdn.com/v4/letter/r/dec6dc/32.png) [@retrolefty](https://forum.arduino.cc/u/retrolefty)\ **Post date:** [May 17, 2014, 5:18pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305/5 "2014-05-17T17:18:53Z")
You likely damaged other stuff on the board sensitive to having reverse polarity applied. It will take some time and expense to replace the obviously bad component(s) only to see that the board still doesn't work. That is too bad because if you had applied the reverse polarity to the external power connector instead of directly to the shield Vin pin you would have suffered no damage because the arduino folks installed a reverse polarity protection diode between the connector and the Vin trace just for such newbie type of mistake. ---
**Author:** ![CrossRoads](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/crossroads/32/214033_2.png) [@CrossRoads](https://forum.arduino.cc/u/CrossRoads)\ **Post date:** [May 17, 2014, 5:41pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305/6 "2014-05-17T17:41:50Z")
That part is the 5V regulator. > **[NCP1117ST50T3G | Digi-Key Electronics](https://www.digikey.com/en/products/detail/NCP1117ST50T3G/NCP1117ST50T3GOSCT-ND/1967217)** > > Order today, ships today. NCP1117ST50T3G – Linear Voltage Regulator IC Positive Fixed 1 Output 1A SOT-223 from onsemi. Pricing and Availability on millions of electronic components from Digi-Key Electronics. Remove it, then measure with an ohm meter between +5 and Gnd. Should see a pretty high resistance, like 10s of K-ohms. If not, remove the 328 chip & measure again. If still low, then something else surface mount is damaged - could be the 16U2 USB/Serial chip, the 3.3V regulator, the op-amp, the FET T1 that does the autoswitching. > **[Arduino\_Uno\_Rev3-schematic.pdf](https://www.arduino.cc/en/uploads/Main/Arduino_Uno_Rev3-schematic.pdf)** > > 81.39 KB ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 19, 2014, 2:18pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305/7 "2014-05-19T14:18:13Z")
Ok... i removed the burnt chip and now (via usb and via 5v pin) it works! In a few days I will buy some reg sot223 5v I will notice you about what will happen 😛 ---
**Author:** ![CrossRoads](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/crossroads/32/214033_2.png) [@CrossRoads](https://forum.arduino.cc/u/CrossRoads)\ **Post date:** [May 20, 2014, 9:21pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305/8 "2014-05-20T21:21:49Z")
Make sure the part you purchase has the same pinout as what's on the board. ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 22, 2014, 6:43pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305/9 "2014-05-22T18:43:16Z")
The only reg I found here, in Italy is a sot-223 5v BUT the pin out is input-gnd-output :~ :~ :~ ---
**Author:** ![CrossRoads](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/crossroads/32/214033_2.png) [@CrossRoads](https://forum.arduino.cc/u/CrossRoads)\ **Post date:** [May 22, 2014, 8:07pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305/10 "2014-05-22T20:07:19Z")
Keep looking then. Or, use a leaded part, and bend the pins to end up where needed. Or get a 5V wallwart, and jumper over the regulator pads (and reverse polarity diode). Or get a USB wallwart, and power the board thru the USB port. ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 5, 2021, 3:59pm UTC](https://forum.arduino.cc/t/i-reversed-gnd-and-vin/234305/11 "2021-05-05T15:59:47Z")