There is (SP name on stick) USB flash which fails to be recognized by Windows 7-10 op system.
No access as drive.
But in Device Manager there appears following:
SMI USB Memory Bar USB drive
Recuva not capable to see it as physical drive
Any ideas how to recover some documents from this drive.

Either (risky) using the MP Tools from somewhere like USBDev.ru or flashboot.ru to re-write chip parameters to the controller firmware or chip off solution by a data recovery outfit.

question is if it can be seen in Disk Management. If not, file recovery software will not be able to see it either. And then, if it's seen in Disk Management, is detected capacity correct? If not then it's some kind of controller failure.

_________________
Joep
http://www.disktuna.com - video & photo repair & recovery service

Device Manager Disk section states this USB disk as:
SMI USB Memory Bar USB drive

Disk Manager as Disk 4.
Removable l: "no media" instead of capacity.

Chip Genius 4.19 reveals:
Description: [L:]USB Mass Storage Device(SMI USB MEMORY BAR)
Device Type: Mass Storage Device
Protocal Version: USB 2.10 <- Hint: This device can run faster when plugged to a USB3.0 port
Current Speed: High Speed
Max Current: 500mA
USB Device ID: VID = 090C PID = 3267
Device Vendor: Silicon Motion,Inc.
Device Name: SM3267AB MEMORY BAR
Device Revision: 0100
Manufacturer: SMI
Product Model: USB MEMORY BAR
Product Revision: 1000
Controller Vendor: SMI
Controller Part-Number: SM3267AE - ISP NONE
Flash ID code: AD3A18030050 - Hynix - 4CE/Single Channel [TLC] -> Total Capacity = 64GB


Now I'm trying to figure out if there is any help for SM3267 from https://www.usbdev.ru/files/smi/smimptool/
But I am not quite sure if this USB flash is fixable.
All ideas are welcomed.

I played around with some of these tools, but their poor documentation is a drawback. You have to understand these tools are meant for vendors, not the general public, and are very powerful.

I would advise getting another flash drive, and playing around with that first to understand whats going on.

I think there were some documents around that were a manual of sorts in using some of the SMI tools.

lastly, the places on the net these tools are found are a swamp pit of malware - be extremely vigilant in protecting against malware when downloading or visiting these sites.

What you would want to do first in the MP Tool is set it up, then get it to identify the nand chip/s. if it cant do that, you have other issues and likely the tool wont help.

There are options to format memory after initial setup (which would be how you "fix" it) make 100% sure you are not formatting memory after setting other parameters.