I was digging through the archives for some information and found an old link to a Medafire share file with Walkman Service Manuals. These were posted to the site in 2008! The 701c downloaded for me but I didn't check any other the other links. https://www.mediafire.com/?n1o0nsxmy4kho
I was looking for one of these and I couldn't find it on the search box, I'll post them on the site in case mediafire.com disappears and it should make searching easier. Sony WM-EX5 Service Manual Sony WM-DD9 Service Manual Sony WM-701C Service Manual Sony WM-DD100 Volume Mute Fix Sony WM-F10II Operating Manual Sony WM-EX808HG Service Manual Sony WM-10, Sony WM-20 Troubleshooting Guide Sony WM-100II, Sony WM-102 Service Manual Sony WM-GC674, Sony WM GC670 Service Manual Phillips D6611
Well done!!! I hate it when SMs original hosts go under and you have to pay for the privilege of getting free stuff for pay... With one exception of wikiboombox where your $$ go for a good cause!!! Correction: the worst is when SM gets unavailable, nowadays I check first if I can get/buy SM and only then consider buying anything.
It's just one page Boodokhan for the volume fix. Your right Jorge, there used to be a lot of hosting sites out that went to pay structure or criminal indictment, the early days of the internet were pretty wild.
Someone uploaded Walkman Manuals to Archive.org, I don't know if there's any new manuals but it's nice seeing them show up. https://archive.org/details/wm-f15_202004/SONYWM-DD_service_manual
https://freeservicemanuals.info/en/servicemanuals/viewmanual/Sony/DD100/ I've downloaded from this site with no issues, that I know of. I just downloaded the Sony WM-DD100 service manual and it looks complete.