You could connect the flash drive to a computer and see if there is a backup on it. If there is, you only need to COPY a 'BACKINFO' folder.
Note: there are lots of variations of flash drives and adapters used for the S4C+. Connecting it to a computer may or may not be easy.
Can the previous owner be contacted for a backup?
I have a similar robot in my neighborhood, it's a 4400 but it's a little shorter then my.
Is your robot a 4400/L30 or 4400/L10?
No backup 
I have no keys for 4400. If you have another robot just like it, it would be best to use that backup to generate the key string.
ABB should still be able to provide the software, just not the key. If they cannot, create a separate thread asking for RW 4.0 - several awesome folks have provided this in the past.
While you gave the controller information, you did not say what type of I/O. The I/O 'cards' may no longer be configured properly to see the inputs. Your original post does not give confidence you can solve this without a better understanding of how this all works. pdl may be on to something about seeking help from someone familiar with your setup.
unfortunately I don't have a backup. will a backup from another same robot help?
It will be the same software options as that robot.
You will need the RW 4.0 software for RobInstall media pool. You listed the previous software as RW 4.0 rev91 (3HAC6811-1.91). If available, look for rev 127 (3HAC6811-2.27) as it was the last & most stable revision for RW 4.0 software. ABB may still be able to provide the software package, but not generate keys for it.
The original S4 - S4C+ floppy drives were all 1.44MB 3.5" pc-compatible. It should be setup to operate the same. Sometimes the ribbon cable on some USB floppy emulator drives needs to be flipped depending on where pin 1 is. I'm not familiar with the Gotek brand.
The key is to have the right software to properly format the USB so it appears to be multiple floppy disks. Most create 0-99 or 1-99 virtual floppies. The same software will likely be used to read each individual floppy.
The "This is not a boot disk!!!!" message on an S4 appears when you try to load software and it does not see the 'abb_boot.sys' file found on disk 1 of the software disks.
You can extract the key string from a backup. You can find the information in this thread:
EE cable? Are you cooling something on the robot or the controller?
Did you download the manuals > S3 M93 Programming Manual and IRB2000 M93 manuals
Yes, you need the Key disk. The RobotWare 3.0 disk pack is the software package, but you need the key disk to load the software along with the variants & options for your robot specified in the encoded key on the disk.
Are you sure it had RW3.0?
IF the Main Computer is DSQC361 (instead of DSQC325), then it is a M97A1 and likely shipped from the factory with RW3.1. The M97A1 is also capable of running RW3.2 if it has the DSQC373 Robot CPU (instead of DSQC363). If it did have RW3.2, then you must reload RW3.2 to avoid bricking the Robot CPU board with the flash overflow flaw.
Though I've never seen 24V Distribution Unit, if you have one as touted in the manuals, there is +24E available at the CP5A connectors located on the unit.
Suggest using the 200V from CP3 on the PSU power supply and getting a small DIN-rail or panel mount switching supply.
I highly suggest using an appropriate fuse to any device.
Have you verified there is 24V at the DeviceNet adapter/card?
This error is typical when the adapter does not have 24V on the DeviceNet connector.
The goal is a grease exchange. You want the new grease to push as much of the old thinner grease out. If you are not pushing a significant amount of old grease out, then you are likely going too fast.
Have torn down just greased robots many times over the years only to find a narrow trail of new grease going from the cavity inlet to the outlet.
If you can quickly get a large percentage of old grease from each cavity and replace it with new without damaging seals, then it's great thing. But many times, it's just Quality vs Quantity.
50080: Position not compatible.
This is the main error. If it is only one position is causing the error, try reteaching the position.
Did something change before the error?
If more than one position causes this error, consider loading a recent backup.
Check the part # on the transformer. For the 1600iD system 09 controller, I only see 2 transformers with 400V input:
3HAC037017-001 (4.2KVA)
3HAC024180-001 (6.0KVA)
For the 2400 system 06 controller, it only shows 1 transformer size is listed for IRB140-6400R. It's 6KVA and doesn't show other sizes.
We load the servo parameters... and then it gives an error again. And you press f1los again, it loads again and the error continues.
Could the servo parameters you are trying to load be corrupt?
Are they the parameters for the S-700?
Google Translate from Turkish:
"model s4c+ now i have a safe teach pendant in my hand and finally diagnostics warm startup mode writes then the screen remains blank ns and en lights do not come on"
Still looks possible the system is not finishing the boot sequence as stated in previous post #3.
Hello friend, I am the same person who had a Fanuc S700. But unfortunately I took it to the scrapyard... now we have that S420... so I also keep the S700 diskettes with the original Kfloppy archived... and the S420.
Glad you have experience with an RH controller. Can you give more detail on the problem, I'm not understanding the exact issue.
What version of RobotWare?
Using Dispense application?
Any other options?
