block erupters not working

[weatherman]

Hey guys ,

Hope this is in the right place.

I have 20 BE and of the 20 I'd say only 10 are working , the rest are either giving me the whole

Do not have user privileges required to open \\.\COM1

or they start up and throw out huge HW: 100% , or they are running slowly e.g. 94mh/s or they just are not putting out anything what so ever

I'm using BFG miner on windows 7

Can anyone help me out with any of these problems?

Cheers

[vm1990]

probably a power issue try unplugging a few miners see if the rest start to mine

[weatherman]

I'll give that a go -

I have 3 x 10 usb hubs , which are rated to 5 amps each and have 5 amps going into it plugged into the wall and into usb port - they are running 9 in the hub + a usb fan to keep them cool.

[jdkackley]

I'll give that a go -

I have 3 x 10 usb hubs , which are rated to 5 amps each and have 5 amps going into it plugged into the wall and into usb port - they are running 9 in the hub + a usb fan to keep them cool.

That's still kinda pushing it, even though you are getting 5 amps at the source, running 9 USB Erupters on that is over working your power supply. Try (if you can) to not use more than 7 per each hub with that power supply.

[weatherman]

Alright , I shall try 7 in each and see how that works out

[madcratebuilder]

How to you know you are getting 5 amps to each hub?  Many wall wart psu's well not deliver the claimed amperage.  Some decline in output with heat.  I would say 80%+ of all problems are power related, not enough power to each miner.  Symptoms well be a low hash rate, under the 333Mh/s spec.  With adequate power my asic's run high 330's and low 340's.  A extra 6-8 mh/s times 60 sticks adds up.