Loud CLICK on Sony Vaio VGN-FS315E PCG-7D1M. Now won't power on

[DanGent]

Hi there,
I've got a Sony Vaio VGN-FS315E PCG-7D1M laptop here. The owner says that she lost the original charger and once tried to force in the wrong charger (not realising the different ends are to stop you plugging the wrong voltage adaptor in!). Not sure whether the charger she forced in was over or under volting but she said that there was a loud click sound (not sure whether windows booted) and then the laptop wouldn't work.

I had a look at the laptop at my house and connected my universal adaptor. It had the correct adaptor and an LED readout showing the correct voltage (19.5V).
The AC power lights turned on and the laptop booted up. It got to the logon screen and I left it there while doing other work on another computer. I heard a loud click sound. Now the laptop won't turn on, the LEDs on the front do nothing if the AC power cable is plugged in.

Has anyone experience of this and what the loud click could be? I tried removing the battery and holding the power button down for ages but to no luck. Is it worth me taking the laptop apart and getting a voltmeter on it? I don't think it'll be anything as simple as a cracked joint soldering the DC jack in....but always worth a look.

I had a look on ebay for a replacement motherboard but either there aren't any or I need to strip the laptop down to read off the proper motherboard name (rather than search by laptop model).

Any help would be much appreciated!

Thanks,
Dan Gent

[ajones]

The only thing I can think of making a loud click would be the HDD arm springing back to the rest position, but the pc should still run POST. Could the click be more of an electrical snap as if something is shorting out?

[DanGent]

honestly it was MUCH louder than the faint click you get from say a broken HDD where it keeps clicking (never realised it was going back to its rest posititon, very interesting).

someone else has told me it could be "arcing". where the electricity travels in the air (where it shouldn't!). and this is supposed to be very loud. I'm going to strip the laptop to pieces and see what I can find. I'll post back the results.

[peterb]

I doubt that it is arcing. However if the earlier adaptor was over voltage or reverse polarity, it may have damaged one f the electrolytic capacitors internally - and when you plugged in the correct PSU, eventually it just packed up - and they do go with a crack - athough usually accompanied by a strong smell.

It doesn't take much over voltage to damage an electrolytic capacitor, although they usually fail open cct, so that wouldn't necessarily stop the laptop from booting - but that would depend where n the circuit it is.

But the only way to find out is to open it up - if it is a capacitor, it will be fairly obvious.

Repair depends on your skill with a soldering iron, location and type of capacitor, and ease of access - and there is a risk that there is more that is not visible.

[DanGent]

thats superb advice peterb. sounds much more likely. i've never replaced a broken capacitor as i've never encountered one. checked many mobos for the tell tale swollen caps (from what i've read) so this should be a first if so. done soldering on DC jacks before and capacitors look easier to take out than them. I can always give it a go if it doesn't cost much.

just a question about your email, one bit i dont understand
"although they usually fail open cct"
whats cct?

i'll open it up now and post back what i fine. much appreciated for the advice!

[DanGent]

Took out all the components, still no lights come and it doesnt power up.
The DC jack is attached to the mobo by a cable so it looks like this
http://cgi.ebay.co.uk/SONY-VAIO-VGN-...item27ab206be4
a clever idea as it speeds replacement but it costs loads. I think I could get one of these though and solder it on the end of the existing cable
http://cgi.ebay.co.uk/DC-Power-Jack-...item56368cbc7d

The DC jack is cracked a little. Not sure if thats why its broke but I got a voltmeter out, my universal adaptor is giving out 19.5V but no matter where I attached the two metal probes (is that the right word?) I couldn't read any voltage (with the adaptor plugged into it and the cable connected to the mobo).

Is it quite easy to check that a voltage is coming through the DC jack? I've not fully taken out the motherboard yet. I'll do that in a bit to check for capacitors. Was just wondering whether people thought it could be the DC jack?