OK few answers.

When I said got 12 meant blew 12 up over a period of time, last three fried ones went on Ebay about a year ago, listed as fried, no scam but still made £40.00.

These were 201 drives, the ones with the add on microstepping chip, state of the art at the time.
I was advised that they would run my big Beaver mill with Superior size 42 steppers which needed the full 7 amps.

Bought 4 wired them in and tested them and seemed OK, then over a period of time they would blow the odd driver, always on swich on, never blow a fuse just bang and the driver was gone.
First two or three got replaced free by Gecko, then I was told no more freebies and I had a motor problem but it was never the same axis blowing up.

Anyway as I had plenty of spares I swapped motors around but still had the same problem. Funnily enough if I took a blown Gecko off an axis and replaced it with an AMD driver I had it worked Ok but very slow as the driver wasn't up to it. I even send an AMD driver over to gecko so they could have a look at one [ Incidentally the 210 soon got replaced by the protected Vampire model shortly after this ]

It was then motor wiring and this was all replaced although it was fine, never blew an AMD.

Also at the time I has having problems with going back to zero, mainly on Z for some reason [ weight ? ] I'd start a job at zero and after a large hole drilling job Z would finish up 8 to12 thou deeper at the end.
No great shakes as they were all thru holes but not right. Got a lot of help off Marriss at gecko but never managed to cure it.

Eventually ran out of spares, switch on one morning and BANG, last Z axis driver gone. Stuck for a driver so jumped in the truck, shot off to ARC and bought a large 80v driver, fitted it and air cut the part twice, seemed Ok, went to zero the Z as normal after each job and it was still on zero.

Replaced to other drives as and when they failed, which wasn't long and then it had all Chinese drives fitted and these drives are still on the machine to this day and that's now been about 7 years of commercial use.

I felt that the problem was that on switch on the Gecko's saw the big 42 motors as a dead short instead of a very low resistance, but no I was told the problem was mine.

later on i then read where Marris had admitted that the 902? microstepping board had a rounding error, the source of my Z driver over shooting.

The last nail in the coffin though was a few years later , reading a post from Marriss over on the zone where he wrote [ and I saved the post in case he ever took it down or edited it ]

my experiance G540 VS Xylotex - CNCzone.com-The Largest Machinist Community on the net!

Post 138 1st paragraph.

Fixitt,

I'm happy to say the G540 is finally squared away. It had a rocky start with the non-motor related features. Some projects are *****-cats and never make a fuss while other projects fight you every step of the way. The G250s in the G540 were *****-cats from the get-go and gave no trouble at all during development. Meanwhile the original G201 was a nasty bear that took over 4 years to subdue; anyone still remember early G201s blowing up for no reason at all on power-up?

These drivers were costing me between £121 and £130 each at the time depending on who I was buying from and different duties and after being raped for well over a grand, plus lost time and then reading a throw away remark like this made my blood boil.

As far as I'm concerned Leadshine cannot do any wrong in my eyes.