SONY VAIO VGN-FW41J switch-on problem

[gulovat]

My SONY VAIO VGN-FW41J has been giving a strange problem, when powering-on: unfortunately the problem cannot be easy reproduced, typically it is shown when powering-on, but not always.

THE ENVIRONMENT: my Laptop is just three years old (out of warranty) - the battery pack is quite down, and shall be replaced, since it is not able any more to keep its charge - the first time the problem showed was after upgrading from Vista to 7 (after a system restore, but in past my VAIO had been working normally long time with Windows 7: indeed none of these conditions seems to be correlated to the problem.

DESCRIPTION : when I press the power-on button, the green light (ring) is on (fixed), the laptop tries to start, but after one/two sec (namely after some "normal internal£ starting noise), it switches-off; I repeat the power-on operation, the problem show again and again, until, at last the laptop is regularly started

(probably after touching the power connector (left side) ? Then all is OK, with any evidence of instability.

The following day, or after the laptop has been switched-off, the problems appears in the same way.

WHAT I HAVE DONE: I had noticed mechanical instability evidence in the power connector, where the

power jack is inserted. i was afraid of some false contacts inside the cylinder.

First of all I checked if the problem is in some relationship with the battery pack, negative, same behaviour with battery inserted or off.

Then I disassembled the laptop, thanks to a quite good guide found on (www.insidemylaptop.com).

No evidence of false contacts could be recognised, when touching either the cylinder or the black cable till the pcb white connector.

The mechanical instability was due to the loose screw to mount the cylinder on the chassis, In order to tighten the screw, I had to replace it with a longer one, even if the mechanical weakness will remain present the same.

Frankly this appears to me as a weak design detail: the connector/cylinder mounting should be made by design stronger, since each time we use the laptop we insert the jack in the connector: for example it could be better fixed by means of a couple of screws, with cylinder wing a bit longer, instead than just one, and the room exists to do that ! (see picture detail). 

The problem was not be corrected after such mechanical operation.

Message was edited by: gulovat