I have a vaio pcg-7l1m which will not power up.

Hello,

When you say you checked the adapter, I assume you mean you put a meter to it and it is giving 18-19 volts. I also assume that no power means no led's, no fans, no nothing.

Before you tear it apart, please try the following to try and get some signs of life.

Remove the battery and try to boot. Leave the battery off for the rest of the testing. Remove the hard drive, and the optical (dvd) drive. There is likely a screw on the bottom that will release the optical drive. Try to boot. If no good, remove the ram and try again. The ram stick(s) are located under an access panel on the bottom of the laptop.

If all this produces nothing, your last effort may be to resolder the dc power jack on the mainboard. This is not that difficult but you need to be careful while doing this:

I like to keep two separate containers for screws...one for those from the bottom, and one for those from the top. If you own a video camera, maybe video the laptop as you do this. It could be a valuable reference when re-assembling it :)

First, remove the access panel from the bottom that provides access to the wireless antennas (2 wires). Pop the connectors off of the wireless card. You must do this to remove the display, as the wireless antennas are in the display. Next you need to remove the top bezel (strip of plastic above the keyboard. You may need to remove some screws from the bottom to release it. Gently, insert a small flat head screwdriver under one of the hinge covers (plastic bump over hinges) and pry up . Usually it is just plastic clips holding it on and it will pop off. You should be able to remove the bezel easily.....gently, remember? With the top bezel off, you can remove the keyboard (may have screws on the bottom holding it, but likely not. Remove keyboard screws on top, disconnect the ribbon cable and remove the keyboard. Now, snake the antenna wires that you removed earlier up through the top of the laptop. Remove any connector cables going from the display to the laptop. Remove the hinge screws holding the display on and remove the display. There might be two screws on the bottom securing the display as well.

Now, remove all screws on the bottom of the laptop and try to gently pop the plastic case apart. There may be screws under the keyboard (on the top side) that hold it together too. Take your time here, paying close attention to any connector wires....BE VERY MINDFUL OF TINY WIRES AND CONNECTORS.

Once you get the case apart, there will likely be a few screws securing the mainboard to the plastic case. Remove these (circle the empty holes from the screws with a marker so you know where they go back in)

With the mainboard out, locate the dc power jack. It likely has 3 or 4 solder joints securing it to the board. With a magnifying glass, inspect the solders for cracks in the solder joint. If they are cracked, that's likely the issue. If not, resolder them anyways. Using thin electronic solder wire (do not substitute with plumbing solder) heat each solder joint, and apply a SMALL drop of solder. Not too much, or it can run down into the connector and bugger things up. Be careful not to touch/heat up any other components near the jack too.

With this done, dry fit (without all the screws) the laptop back together. Make sure all the little connectors have been re-connected and while thinking happy, positive thoughts, try to power it up :)

If this won't get it to power up, then you likely need a new main board. If you can't find one for a reasonable price on ebay, get a new laptop. In my experience, Sony will not sell a mainboard to anyone other than an authorized Sony service shop, and even if they will, it will likely cost $400 or more.....too much to spend on a part (likely refurbished) with a 90 day warranty.

Hope this helps! Post a comment and let me know how you made out.