Bharathvajha

I was cautious while opening and cleaning.checked it thrice. still couldn't turn it on

My friend is having a Dell inspiron 15r 5537. Its configured with intel core i5 with Amd HD 8700 series GPU. It was running too hot and very slow. so i replaced the thermal paste, inserted a SSD (for bootng windows and installing apps) and bought a Caddy for a HDD (for storing Data). After reassembling the laptop it is giving 7 beeps and it is not turning on. After referring the Dell site it says replace/reseat the motherboard for 7 beeps. So is there any solution or should i replace the motherboard?

Thanks for the response.

I have a dell inspiron 7520. It's a good machine. I used to game a lot and work a lot. But after a couple of years it started to overheat so bad i have to shut it down often. Playing Cricket 2007 or need for speed hot pursuit(2010) even makes it overheat. It has AMD Radeon HD 7700M series. I will be buying a new laptop next year. but for time being i need this one to work well like it used to be. Due to overheating i cant take it to my college works. Should i replace the thermal paste? please advice.