Hi,

I have an SD-card, which isn't readable anymore. Tried 2 winows PC and one Linux. On Linux the card get's at least recognized as mmcblk0, causing lots of error messages in /var/log/messages like buffer I/O error. The messages stopped after lots of screens full of errors. Then I tried to read it via 'dd' but that just stopped with copying 0 bytes. fdisk can't access the card.
I had the idea that maybe it'd be readable with reduced speed, since it must be a hardware problem. Is there any entry in /sys where I can change the read speed of an SD-card-reader?

No speed will not help.
Use testdisk and see what you can get.

Some OEM's of memory offer tools also. See if your brand does.

thank you, tried "dd_rescue" read a few kilobytes, but stopped after 1MB. I'll look for something from OEM's.