USB ports on T-42

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SlamX · #1 Post by **SlamX** » Sat May 14, 2011 2:57 pm

My T-42 seems to have problems on the usb ports. I have a Dell Inspiron laptop of same vintage and its usb ports work great.

On the T-42 an external 2.5" drive will not be recognized but some other low power usb devices will be. As I said on the Dell it runs the external drive fine.

Is this a low power issue with the T-42 or some other failure on the usb ports.

I cannot seem to isolate the problem.

Running XP Pro SP3 on it.

Neil · #2 Post by **Neil** » Sat May 14, 2011 3:50 pm

Are those devices that do work, doing so at 1.1 speed instead of 2.0?

This may just be a power output problem, but often USB trouble (among many others also) on these machines can be caused by failing solder joints on the SouthBridge chip.

SlamX · #3 Post by **SlamX** » Sat May 14, 2011 4:52 pm

Come to think of it I believe usb 1.1. devices do work and it seems the 2.0 are having the problems.

Everything else seems to be working fine video etc.

Can the southbridge chip be reballed? Or should i get a new motherboard?

Neil · #4 Post by **Neil** » Sat May 14, 2011 10:26 pm

SlamX wrote:Can the southbridge chip be reballed? Or should i get a new motherboard?

Yes, can be professionally repaired. Replacement board might be an option too. Before doing either, I would experiment with applying pressure to the chip. I once was successful using a small piece of .25" thick foam between the chip and the wireless card, and another piece of foam between the wireless card and the palm rest. Once everything was screwed back together, it gave the palm rest, touchpad and keyboard a nice solid feel, and corrected the problems I was having with the Southbridge chip too! Cost....only a little time.

GACrabill · #5 Post by **GACrabill** » Sun May 15, 2011 11:36 pm

SlamX wrote: ... On the T-42 an external 2.5" drive will not be recognized but some other low power usb devices will be. As I said on the Dell it runs the external drive fine.

Is this a low power issue with the T-42 or some other failure on the usb ports.

The USB 2.0 standard calls for 500ma of power delivery. Most 2.5" external hard drives require 600ma to 700ma of power either during start-up or sometime during constant usage. Some laptops can deliver more than 500ma thru their USB ports and therefore have no problems with such drives. Other laptops may have problems with such drives at random times or the 2.5" drives themselves may require slightly more power as they age and then they start having odd issues with laptops that had worked previously.

That's why someone developed the "two USB connector Power cable" for attaching external drives. Here's one and I am sure there are USA sellers also :
http://cgi.ebay.com/USB-2-0-2-Male-mini ... 1c15e3a09d

These cables allow external drives to draw up to 1000ma of power if they need it. I have two such cables that we use with the external drives that are used for image backups ... I don't want to find out later that a backup was corrupted due to a power issue.

One of my external 2.5" drives ran for over a year with a normal 1-connector cable and then had errors during multiple file creations over the course of a few days. Various tests showed nothing was wrong with the drive so it now uses a 2-connector cable and has had no problems since.

If giving up two USB ports on the laptop is a problem, then think about getting one of the 2-port "inside-hide" USB cardbus cards :
http://cgi.ebay.com/AKE-Inside-Hide-PCM ... 4aaaf6fa86

I would try the 2-connection cable before worrying about a motherboard problem.

#6 Post by **RealBlackStuff** » Mon May 16, 2011 7:13 am

There's a Sticky about USB ports not being recognized/work only at 1.1 speed: http://forum.thinkpads.com/viewtopic.php?f=2&t=70955

This is mostly due to the Southbridge chip becoming unsoldered.
That's the big Intel chip under the wifi-card (under the palmrest).
Applying pressure there (as Neil suggested) may provide a temporary fix, but since this chip supports so many more important functions (hard disk, CD, USB, etc. to mention but a few) it's better to get it fixed properly.
We supply a motherboard exchange service (see The Board Room link in my signature) which will take care of your problems.

Mike Blake · #7 Post by **Mike Blake** » Mon May 16, 2011 5:11 pm

I think GACrabill has a valid point worth checking into first.

I had similar problems that a powered hub cured in one case and that "two-pronged" USB connector fixed in another.

SlamX · #8 Post by **SlamX** » Tue May 17, 2011 7:30 pm

Thanks for all the replies.

Something is definitely wrong with the USB ports. Being that the cost of these units has dropped a lot in recent years I don't think I will waste a $100 to fix it.

I got a USB pcmcia card and I will use that to try and use devices. All other parts of the laptop seem to be working fine. If it is a southbridge issue I would suspect over time I will see more components fail.

SlamX · #9 Post by **SlamX** » Sat May 28, 2011 7:58 pm

I did some poking around and I think this is a southbridge issue. When I press on it in the area of the palmrest the usb ports go haywire.

Any suggestions where I can get this reballed for cheap but fro a good reballer.

ajkula66 · #10 Post by **ajkula66** » Sat May 28, 2011 9:03 pm

SlamX wrote:
Any suggestions where I can get this reballed for cheap but fro a good reballer.

I don't think that you can have it both ways.

It's either cheap or from a good reballer...

Honestly, I believe that this is as good of an offer as it gets:

http://www.theboardroom.info/index.html

Good luck.

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