I have a Seagate Free Agent external drive that I've had for about 5 years, and it has always worked well. Now, it won't power down when the computer powers down, It  stays on, and the light pulsates constantly. Any body have any ideas why this might be? Thanks!

Unplug it completely and let shut down. Reconnect it and try running a diagnostic program on it when you reboot.

Thanks, John. It's working now. I downloaded a seagate diagnostic program, I'll give it a go and see if it can determine what happened.

5 years would be the maximum I'd keep any hard drive, internal  or external in service. I put them aside as back up- back ups. I have almost every drive I've ever owned in a couple of shoe boxes. There's a 5 Gig drive in there from my first P3. 
 
SATA hard drives have become so inexpensive. 
1TB 7400 SATA for under $60
2 TB 7400 External for under $100 
What I like is the new externals no longer need a separate power supply and they are way smaller. 

On somewhat of a similar note.......NewEgg is currently having a sale on a Seagate 1TB 7200RPM internal HDD for $49.99 (use promo code:EMCPAPF23) . (A possible backup solution??)
 
http://www.newegg.com/Product/Product.aspx?Item=N82E16822148840&nm_mc=EMC-IGNEFL090414&cm_mmc=EMC-IGNEFL090414-_-EMC-090414-Index-_-InternalHardDrives-_-22148840-L0B
 
 
 

I bought a Seagate recently that I am using as my C drive. It seems to be a bit slow on loading up my OS compared to my last drive. Granted it's a larger drive ...I went from a 250gb to a 1tb. I'm not overly impressed with the speed.
 
I guess as a backup it's might be ok though. 

Thanks guys for the replies. Been out of town, and just getting caught up. This drive is still acting strange, so I'm going to order a new one today!

I have the same drive and recently I experienced the same problem.
 
I backed up the 500gb and took it out to pasture.  noticed a lot of read errors when I was backing it up too.  was only a USB 2 drive and upgraded to a 3TB USB 3 drive and couldn't be happier.
 
I don't know why it pulses or won't shutdown properly.  really annoying to as all the lights go out in the room everything gets turned off and shutdown but there is this one pulsing light tormenting me.
 
I think it just means the drive is about to die.  $60-120 you can get a replacement that will blow it away.
 
BACKUP UP YOUR STUFF NOW.  That's my recommendation.

Thanks,MachineClaw, yes, I agree, I think it's about to die. I  ordered a 3 TB drive from B&H today, I get it Wednesday. Thank again!