Did I fry my Mega's 5v regulator?

I have searched the forum and read about this similar issue:

Before I begin, let me say that I very likely am the cause of this. I have loaded Repetier server on a Raspberry Pi Zero W and it is working great. Links up with Repetier host and everything. It is still working even with my problem.

I decided that rather than running a cell phone charger to my Pi for power, I would try to find suitable 5V pins on the ramps board. (this works great with Rambo) I found 5v pins but they power down when the Mega resets which puts the whole thing into a boot loop. SO, searching the ramps board with the trusty volt meter, I seem to have shorted out something that powers my LCD’s backlight. At first, it got VERY bright and stayed that way after resets. I adjusted the POT on the LCD and it was then fine. I thought all was good so I couldn’t leave well enough alone. I tried to power the Pi off some 5V pins and now my backlight is pretty much nil.
I don’t use the LCD for much, and I could just do away with it. Like I said, the MPCNC works fine using Repetier either connected via usb to the PC or wirelessly using the Pi.

Did I fry the 5v regulator on the Mega, and if so, am I going to cause further issues if I continue to use it?

Sounds like it is the 5V reg. You can power it separately, or replace the reg. The reg, and the green plug have no room for any extra fans, leds, power draw. So make sure to keep power draw on the other side of the green plug, I know it is a convenient place to get 5V but it just can’t handle it, and the LCD.

I have replacements from a reputable company in the shop if you have really good solder skills.

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Thank you Ryan. I took one from an extra Arduino Uno I had and put it on the Mega. All is well!

I’ll order extras next time I get some stuff from you.

I’m figuring I can hack a car phone charger’s guts into the 12v input (on the other side of the green plug) and run my RasPi from the resulting 5V output.

This is all unnecessary really, but I can’t help it…It’s who I am.

Pi’s take a bunch of current. I don’t know much bout the zero, but the full size ones are all 1A or so.

You can buy cheap DC to DC converters that are large input, like 5V-15V and output 5V, or variable voltage. You can find them on eBay, Amazon,z or alibaab type places. They are a buck or two each. Just make sure the amperage rating is 2x what you plan to use it for or so.

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That’s what a car cellphone charger is. It takes 12 to 19vdc and drops it to 5vdc. Sure we could order one from the internet, but I have three car adapters sitting on my desk right now!

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I think you fried a motor driver in the first place.

I had the same issue a while ago, the screen became bright and then after a while, nothing, and the 5V regulator was dead. Changing the regulator ended up the same, the arduino was just dead.

I suggest you to not use these drivers anymore with the new arduino, last time I reused them I fried the new arduino instantly.

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Turns out I didn’t fry anything! My powered usb hub was providing too much current to the pi and it was being passed along to the Arduino which already was getting power via the ramps board’s “green plug” that has 12v going to it.

I took apart a car charger and spliced its input into the 12v power supply going to my ramps. The 5v output is now powering my pi. It is all working great now. I even printed a little box to hold the old charger. I have a pi running my 3d printer and another running my MPCNC.

I appreciate y’alls input!

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Well that’s a new one.