Laptops Dell Inspiron 15 won't start

[vigilante]

My 4+ yr old Dell Inspiron 15 suddenly stopped and just won't start at all. Nothing happens if I press the power button and I can't hear any sound either. If I plug in the charger, the charging LED turns on for a second and goes off. Although the battery has gone bust from a long time, I used to run it on AC power only and I know the charger is working. I showed it to a local repair shop, and he says it might a Motherboard issue (He didn't seem too sure so I took it back).
Anyone can suggest a good reliable laptop repair shop in Pune preferable around Kondhwa, Camp, Kalyani Nagar?
A friend of mine has a similar issue and the Dell authorised service people have told him the mobo needs to be replaced costing around 7k. How reliable would the authorized service center be? Is this a fair price? Is it even worth replacing a new Mobo on a 4+ yr old machine when the other parts might also have been worn out?

 

[indianv2]

You can try starting the laptop by keeping the "D" key on the keyboard depressed and then pressing the Power button. If all is well with the power circuitry of the laptop, it should get into the Laptop diagnostics mode. If this step does not work, the power supplying circuitry has an issue.

 

[vigilante]

You can try starting the laptop by keeping the "D" key on the keyboard depressed and then pressing the Power button. If all is well with the power circuitry of the laptop, it should get into the Laptop diagnostics mode. If this step does not work, the power supplying circuitry has an issue.

Haven't had a time to look at it in a while. Will try the above technique and see if it works out. (fingers crossed)