Can USB cause system failure?

Can plugging a USB cable in cause a system failure?

I replaced the DC power jack in T40p and, when owner attached USB
cable to sync her PDA, the system went dead (not even AC or battery
indicator lights). I disassembled it again, reseated the various
connectors (power, keyboard, touchpad), and it once again worked
fine. She plugged in the USB cable and, once again, the system went
dead. So I am now going to disassemble it again and try to figure out
what's going on.

On Jun 20, 6:52 am, News <N...@Group.name> wrote:

>
> You may be attempting to draw too much power through the USB port.
>
> Has the PDA ever sync'd properly with the T40p? Any machine? What PDA?

The PDA (an HP, not sure what model) always sync'd properly with the
T40p, until this failure occurred.
According to owner, the most recent failure occurred as a result of
plugging the cable into the USB port; the PDA was not even attached to
the cable.

One of the two USB ports is missing the plastic piece which ensures
the plug can only be inserted one way. So a USB cable can be inserted
right side up and also up side down. Inserting the cable, even right
side up, causes the system to crash immediately (hardware crash...no
messages, no blue screen, just an immediate complete power down). I
pulled the battery and AC, waited 20 minutes or so, and it once again
booted up.

Since the USB ports are attached to the mobo, I think I'll recommend
the owner uses the other USB port.

On Jun 20, 2:13 am, pageo <geob...@gmail.com> wrote:
> Can plugging a USB cable in cause a system failure?
>
> I replaced the DC power jack in T40p and, when owner attached USB
> cable to sync her PDA, the system went dead (not even AC or battery
> indicator lights). I disassembled it again, reseated the various
> connectors (power, keyboard, touchpad), and it once again worked
> fine. She plugged in the USB cable and, once again, the system went
> dead. So I am now going to disassemble it again and try to figure out
> what's going on.

It sounds like the USB Ports are damaged. You can buy a PC Card for
20-30 bucks that will give you additional USB ports if needed.

pageo wrote:
> On Jun 20, 6:52 am, News <N...@Group.name> wrote:
>
>> You may be attempting to draw too much power through the USB port.
>>
>> Has the PDA ever sync'd properly with the T40p? Any machine? What PDA?
>
> The PDA (an HP, not sure what model) always sync'd properly with the
> T40p, until this failure occurred.
> According to owner, the most recent failure occurred as a result of
> plugging the cable into the USB port; the PDA was not even attached to
> the cable.
>
> One of the two USB ports is missing the plastic piece which ensures
> the plug can only be inserted one way. So a USB cable can be inserted
> right side up and also up side down. Inserting the cable, even right
> side up, causes the system to crash immediately (hardware crash...no
> messages, no blue screen, just an immediate complete power down). I
> pulled the battery and AC, waited 20 minutes or so, and it once again
> booted up.
>
> Since the USB ports are attached to the mobo, I think I'll recommend
> the owner uses the other USB port.
FWIW, I do own a machine which crashes hard when I try mistaken to
insert a USB cable the wrong way. It looks like the design of the port
is such that the protective tab does not prevent some electrical contact
to happen with the cable is inserted the wrong way.

Got me very concerned when this happened, but restarting the machine and
being more careful when inserting the cable works fine.

--
John Doue