# Arduino Mega 2560 **URL:** \ **Category:** Motors, Mechanics, Power and CNC\ **Created:** [May 27, 2023, 5:43pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754 "2023-05-27T17:43:05Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![vladutm](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/vladutm/32/935917_2.png) [@vladutm](https://forum.arduino.cc/u/vladutm)\ **Post date:** [May 27, 2023, 5:43pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/1 "2023-05-27T17:43:05Z")
Hi! If somebody can help me, I have a problem to my Arduino Mega2560 power pins (pins that provide 5V) and it is that they provide 4.2V only. Does somebody know what's the problem and how to fix it? ---
**Author:** ![madmark2150](https://avatars.discourse-cdn.com/v4/letter/m/b487fb/32.png) [@madmark2150](https://forum.arduino.cc/u/madmark2150)\ **Post date:** [May 27, 2023, 5:44pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/2 "2023-05-27T17:44:53Z")
The. +5 is an INPUT. You can't run more than an LED or two from it. ---
**Author:** ![vladutm](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/vladutm/32/935917_2.png) [@vladutm](https://forum.arduino.cc/u/vladutm)\ **Post date:** [May 27, 2023, 5:46pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/3 "2023-05-27T17:46:47Z")
I use one for the LCD and another for a SD card module. Does these modules need more current? ---
**Author:** ![vladutm](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/vladutm/32/935917_2.png) [@vladutm](https://forum.arduino.cc/u/vladutm)\ **Post date:** [May 27, 2023, 5:48pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/4 "2023-05-27T17:48:15Z")
The interesting fact is that one year ago it worked and the electric circuit was the same. ---
**Author:** ![madmark2150](https://avatars.discourse-cdn.com/v4/letter/m/b487fb/32.png) [@madmark2150](https://forum.arduino.cc/u/madmark2150)\ **Post date:** [May 27, 2023, 5:56pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/5 "2023-05-27T17:56:46Z")
SD card runs over 100mA. It only worked before briefly as the onboard voltage regulator gets hot and the voltage drops. What are you powering this from? I use separate 5v @ 3a power supplies to run my mega projects. I built a power disturbution board that piggy backs onto the terminal shield for solid, dependable, wiring. ![20230217_170404](https://europe1.discourse-cdn.com/arduino/original/4X/a/3/b/a3b2b9fb6a08c40ee46f2fd7fabad91a4a8debe3.jpeg) ---
**Author:** ![anon85221860](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@anon85221860](https://forum.arduino.cc/u/anon85221860)\ **Post date:** [May 27, 2023, 6:00pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/6 "2023-05-27T18:00:39Z")
> [@vladutm](#): > > Does somebody know what's the problem and how to fix it? What is VIN (what is the source, how many volts)? ---
**Author:** ![vladutm](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/vladutm/32/935917_2.png) [@vladutm](https://forum.arduino.cc/u/vladutm)\ **Post date:** [May 27, 2023, 6:02pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/7 "2023-05-27T18:02:36Z")
I have a 9V 2A DC adapter for the board. If I add a separate 5V source to power those modules it should work, isn't it? ---
**Author:** ![anon85221860](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@anon85221860](https://forum.arduino.cc/u/anon85221860)\ **Post date:** [May 27, 2023, 6:03pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/8 "2023-05-27T18:03:31Z")
> [@vladutm](#): > > I have a 9V 2A DC adapter Regulated - or Unregulated (probably "Un-"). ---
**Author:** ![vladutm](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/vladutm/32/935917_2.png) [@vladutm](https://forum.arduino.cc/u/vladutm)\ **Post date:** [May 27, 2023, 6:04pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/9 "2023-05-27T18:04:37Z")
Yeah, it's an ordinary DC adaptor. ---
**Author:** ![anon85221860](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@anon85221860](https://forum.arduino.cc/u/anon85221860)\ **Post date:** [May 27, 2023, 6:05pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/10 "2023-05-27T18:05:35Z")
. Get a 9V regulated supply. ---
**Author:** ![madmark2150](https://avatars.discourse-cdn.com/v4/letter/m/b487fb/32.png) [@madmark2150](https://forum.arduino.cc/u/madmark2150)\ **Post date:** [May 27, 2023, 6:08pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/11 "2023-05-27T18:08:24Z")
Or a nice +5v supply and get rid of the wasted heat and limits of the onboard +5 regulator. ---
**Author:** ![vladutm](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/vladutm/32/935917_2.png) [@vladutm](https://forum.arduino.cc/u/vladutm)\ **Post date:** [May 27, 2023, 6:10pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/12 "2023-05-27T18:10:44Z")
Ok. Thank you so much. I'll try to fix it. ---
**Author:** ![JCA34F](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jca34f/32/340148_2.png) [@JCA34F](https://forum.arduino.cc/u/JCA34F)\ **Post date:** [May 27, 2023, 7:47pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/13 "2023-05-27T19:47:30Z")
If you are putting 9V on the VIN pin or barrel connector and the 5V 1 Watt regulator is dropping 4V, then output current is limited to about 250mA. if the load is greater, the voltage may sag below 5V and the regulator may overheat and shutdown. Can you measure the current into the VIN pin? ---
**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:** [November 23, 2023, 7:47pm UTC](https://forum.arduino.cc/t/arduino-mega-2560/1131754/14 "2023-11-23T19:47:39Z")
Closed on November 23, 2023, 7:47pm UTC This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.