Hi, I have a late 2008 Macbook running Mavericks, and I'm unsure if the usb drives are working correctly. A couple of weeks ago, my LaCie external hard-drive stopped working. Or rather it wasn't showing up when I plugged it in. The light on the drive only came on intermittently. Each time I connected the drive I could hear it starting up, but nothing appeared on the desk-top, 'devices' or disk-utility. I contacted LaCie and they sent me a cable as they believed that was the problem. The new cable improved the connection (the light remained on & and drive sounded like it was running) but ultimately nothing appeared on the desktop, or in disk-utility. When I plug a usb zip drive into my Mac it appears on my desktop and on disk-utility, and works satisfactorily. My mouse also works fine via my usb. However, when i connect my printer/scanner, sometimes it is recognised as my related scanner program starts up, but sometimes I have to select print from a document or manually select scan from the printer. I expect LaCie will ask me to send my external hard-drive to them, which I'll do if it is the only way of fixing it, but I want to rule out that it's not something to do with my usb drive. I'm going to take my Mac to the apple store, but thought I'd ask the pooled wisdom here first Is there any way the usb could be recognising some devices or only showing some devices as connected? And if so, is there any way i could solve that? I'd be so grateful for any information/solutions you may be able to provide Thanks (edit) just read or someone with usb problems doing a smc and pram reset which solved the problem. Is this something I should look to do?