Game Doctor copier won't write BRAM to disk?

I got a GD SF3 copier that seems to be working perfectly. Loading games from/to disk, real time save, dumping carts all work. However when I went to write my sram from EarthBound to a disk so I could write a different game to the copier I discovered that it wouldn't work and I'm clueless as to why. I insert a blank disk previously formatted with the SF3 to 1440k and choose write BRAM. The drive clicks twice and progress indicator goes to 31% and then says 'disk verify error!'

Anyone know what's going on here? Everything else is working but not being able to dump sram is a serious pain.

 

Hmm, I certainly would have thought the same, except it happens with every disk I have.
Oddly, just now I tried writing BRAM to disk after playing Zelda on the copier and it worked just fine- so I guess it is a game-specific issue?

 

Well, I swapped out the FDD with a brand new Mitsumi drive I had, (which is a lot quieter so not a total loss) but the issue persists.
Not sure where to go from here in regards to determining the source of the problem. I can probably pick up some new disks somewhere to see if that's the issue. In regards to power supplies, what else could I use? I'm currently using a Genesis adapter to power it (as recommended by Tototek), is there something else I could try? I have power supplies for quite a few consoles (NES, SegaCD, Twin Famicom, SFC) around but don't want to blow the thing up

 

As long as the voltage and polarity are correct, nothing will blow because of a different PSU. The unit will only draw as much power as needed. Only the underspecced PSUs (not enough amps) can be a problem.

There seem to be a few cases of voltage regulators crapping out. Are you able to verify if the floppy power connector inside the unit is supplying the proper 5V (volt-/multimeter)? Failing that, you could provide external power to the drive, see if that changes anything.