I have a WD "MyBook" 500GB external drive. I substituted the drive inside with a Samsung 750GB drive, to get the higher capacity. But this combo has a problem: it gets the dreaded window's delay write failure on $Mft when idling.

I read some where the WD enclosure goes to sleep mode once a while. If that's the case maybe the samsung drive can't handle that.

Has anyone else experienced this problem? Is there a solution, other than putting back the WD 500GB drive in it?

try to use jumper to limit Samsung's SATA speed to SATA1 1.5GHz
Also you can check and change APM and PM features of your drive with HDDscan

_________________
SAN, NAS, RAID, Server, and HDD Data Recovery.

Thanks for the reply. Got hddscan. It gave me a cannot-display-xml-page error. But the part about power mgmt feature does work. It seems to show the drive to have all those disabled. So it must be the WD enclosure that's doing the go-to-sleep part.

I can try setting the jumper to 1.5 speed. But what would this do to the sleeping problem?

you can try to access drive wuth HDDscan inside USB box too

_________________
SAN, NAS, RAID, Server, and HDD Data Recovery.

yes. hddscan shows the APM and PM power features as being supported by all disabled. don't know what next to do. i get a feeling that the WD Mybook enclosure triggers a spin-down in the samsung drive, but when later accessed, the enclosure doesn't trigger a spin-up or is unable to do it, nor does it pass the access directly to the drive so that it could spin-up by itself. Apparently what ever the arrangements between the enclosure and the WD drive, that seemed to work. But not with a non-WD drive.

Any more thoughts?

There is mothing special about a WD drive. It's something else

_________________
SAN, NAS, RAID, Server, and HDD Data Recovery.

what i do now, after it gets into this failure mode, is to pull the power cord from the mybook enclosure and plug it back in. this starts the drive again. this is very inconvenient to say the least. nor can i assign a drive letter of choice to it, bcs every time this happens, after i get it back, it gets a new drive letter (the next available one) by itself.

You have an enclosure problem compounded by a Windows problem. There is a tool for Windows to reserve drive letters, if that matters to you. http://www.uwe-sieber.de/usbdlm_e.html

My advice? Throw away the MyBook enclosure. If you like its aesthetics, get a better USB controller board inside the enclosure. It is really a piece of trash. I like Acomdata enclosures, by the way.