@mitu OK, strange, but I tried on a different laptop and it works fine. Made the backup. The other sd card backed up just fine on the laptop that this sd card would not. I'm not sure what the issue is, but it is done ... both sd cards backed up. Thanks again!

@GoldManSex778
I did try that and still ran into issues so said hell with it...erased everything off of USB drive and started from scratch at instructions for manually mounting. Since I had copied everything over using a previous copy method and that might have been causing issues.
Right now I'm copying the correct directory structure over, so hopefully everything will work properly now once I do the rest of the steps lol. If anything I've learned some things about Linux from the experience.

Final Update: Success! Thank you all for helping!

For anyone ever going through this, one of two things I think was the issue: NOT following the instructions to the letter manually mounting, or my UUID was wrong. I had the last char wrong, but could have sworn it was something different before(either new copy changed UUID, or was my error). Resolution on a laptop helps reading the characters much more clearly than on the TV screen where its almost a guessing game.
I used WinSCP to confirm that its working, and booting up was much faster!

@mitu Thank you for the advice, I'll do that.

I consider this problem solved.

This is the first time I ask for help on this forum and I'm not desapointed :)

@taiJones00
So does the wireless work on the game girl? It would be cool to write a script to easily disable and enable it to save power.

Is the hdmi port still accessible? and then you might be able to sync a wireless controller and play on a tv.

The RPI3b+ can get hotter than any of the other models, I wonder if installing a fan would be possible. Of course that would use more power, depending on the emulations you want to use, it would be easy to down_clock the cpu and benefit as well.

Or maybe I overlooked, or jumped the gun on what was the problem.
If you see the pretty rainbow screen then you wrote the image correctly.
It may be very likely as I was reminded in the forums that there are different versions of the retropie image that will work for the different raspberry pi models. The pi 1/zero are bundled up into one image and the pi 2/3 are bundled into a different image, with older images not supporting the pi3b+.
I don't know about the 1b+

@Jiryn It could be that those cards are not compatible with the pi3, or they could be bad. Stick them back in your pc and run a check disk on them.

Here is a list of compatible sd cards https://elinux.org/RPi_SD_cards

Your cards do not show up there but a 256 Samsung EVO PLUS is listed as compatible.

If you want more space you will likely need to consider using a usb mounted hdd or thumb drive.

Here is another relevant discussion https://retropie.org.uk/forum/topic/783/largest-size-micro-sd-card

@mitu thanks! I figured maybe I needed to remove certain pieces and start from with new image. Before I do that let me see if I can see if I can generate the pishrink error again or find some
Notes I may have taken months ago. I do recall the error ultimately having to do with the external hard drive not having a certain access. I will try this tomorrow hopefully it will take me hours to run this again until point of fail. Part of me says to add more internal storage and try pishrink internally and not on External drive. I will also lookup what version Retropie I am running. Thanks!!

very nice, saving for further reference. Thanks

@garradam not safely shutting down can potentially cause corruption of your sd card. If your pi freezes you should remotely access your pi through ssh and safely shutdown that way. Often times it's only emulation station that isnt responding. There are a number of easy to use ssh apps for smartphones that are very convenient to use.

@ballboff AFAIK, it depends of the licenses you acquired and the laws in your country. If either of them do allow copying the roms on the cartridges for private use, you should be on the safe side. If not, you're very likely violating those licenses and/or laws.

Thank you very much, your suggestion was right. Without the nespi case everything works fine. Thank you so much. Now I have to solve another problem that I don't have in my cabinet. Don't know why the controllers swap themselves after some reboot. I don't touch anything, simply turn off, turn on and magically pad 1 becomes 2 and 2 becomes 1..... howhever, don't wanna go out of post, I'll post it in another one. Thank you again.

Thankyou sir!

@RetroFreak89 i first used several class 4 kingstons i bought at walmart and best buy. I got data corruption all the time on them. Went to samsung after that. Not a single data corruption on the samsung evos.

@Dalrint said in So I'm trying to back up my retropie SD Card...:

One is a drive in a format windows keeps asking to reformat ( G: )

Windows can't read the Linux file system on the second partition, because of Microsoft's worldview of "there are no other systems next to ours". That said, asking to format an unknown partition goes beyond bad manners in my opinion, as it can cause serious data loss for the user.

@Dalrint said in So I'm trying to back up my retropie SD Card...:

So I tried it without worrying about it, yeah. And it did indeed do that! Awesome.

Did you expand the filesystem to the bigger SD card after the migration? If not, see these instructions how to do it.

@jjack229 @herb_fargus Thanks for the replies!

@matitrol said in Partitions in the SD:

Is it a card problem or something?

No, that's normal. The 1st partition is a boot partition and the 2nd one is a Linux partition. On the 1st boot, the 2nd partition will be resized to fit the rest of the free space - up to 16 Gb.

Thanks!!