This may be old news to most of you, if not ALL of you, but I thought I would post this experience here for those who have never ran across this problem.
I recently repaired a Toshiba laptop that would consistently shut off shortly after being powered on. My first thought was that the machine had a bad power supply and was staying on long enough to drain the residual power from the battery.
Not the case.
Long story short, the problem turned out to be the power switch. On this particular model, Toshiba used a kind of membrane contact switch in the form of a small adhesive backed piece of clear plastic that encased the actual membranes and was simply stuck to a part of the case. The external portion of the switch, the one on the top of the upper case that the user presses, simply pressed down on the membrane switch using a short plastic post.
Apparently, over time, the membrane weakened to the point that it would not seperate and effectively kept the switch in a 'pressed' condition, thus the consitent shut down.
The fix, since Toshiba (as far as I can tell) does not sell a replacement, was to take the assembly off and warm it up a bit (the membranes are enclosed in a thin sheet of plastic), allowing the two contact surfaces to seperate. In addition, I slightly shortened the plastic post to ensure that no pressure was maintained on the membrane switch once the user's figure was lifted from the switch, and this worked fine.
Hope someone finds this useful.
Cheers
I recently repaired a Toshiba laptop that would consistently shut off shortly after being powered on. My first thought was that the machine had a bad power supply and was staying on long enough to drain the residual power from the battery.
Not the case.
Long story short, the problem turned out to be the power switch. On this particular model, Toshiba used a kind of membrane contact switch in the form of a small adhesive backed piece of clear plastic that encased the actual membranes and was simply stuck to a part of the case. The external portion of the switch, the one on the top of the upper case that the user presses, simply pressed down on the membrane switch using a short plastic post.
Apparently, over time, the membrane weakened to the point that it would not seperate and effectively kept the switch in a 'pressed' condition, thus the consitent shut down.
The fix, since Toshiba (as far as I can tell) does not sell a replacement, was to take the assembly off and warm it up a bit (the membranes are enclosed in a thin sheet of plastic), allowing the two contact surfaces to seperate. In addition, I slightly shortened the plastic post to ensure that no pressure was maintained on the membrane switch once the user's figure was lifted from the switch, and this worked fine.
Hope someone finds this useful.
Cheers
