Olympus V-90 Digital Voice Recorder. Service manual or advice to enter its service mode

[Peter]

I have an Olympus V-90 Digital Voice Recorder

Can anybody tell me where I can get a service manual for this unit. I
am hoping that it has a 'service mode' that will allow me to recover
accidentally deleted (but not overwritten) data in its 64MB NAND Flash
Memory (TC58V64FT)

Failing that I plan to remove the memory and attempt get a memory dump
on a commercial flash device reader.