Dell Vostro 3700 Won't turn on after CPU FAN & HEATSINK REPLACEMENT

[rwolford87]

So a friend of mine gave me her 17" Dell Vostro 3700 Laptop to fix. It was getting very hot, almost too hot to touch, the fan would turn itself on and off, then it would go to the blue screen of death. All within about 10 minutes of start up. After doing some research, I found that these laptops are known for problems with the CPU fan & heatsink. So I decided to open it up, replace the CPU Fan & Heatsink assembly, and remove the old thermal paste and apply new Arctic Silver 5 Thermal Paste.

I put everything back together, turned the laptop on, and it worked perfectly. The fan turned on and stayed on when operating, and no more blue screen of death. While working to make the laptop operate faster, I found that it was infected with the CryptoWall 3.0 virus (really bad, encrypts your files and makes you pay to get them back). Did some clean up, got rid of the virus, installed some malware & virus protection software, then shut the laptop down. The computer ran for a good 3 hours after I replaced the parts without any hardware issues.

Just the other day I went to turn it on just to double check everything before giving the laptop back, and found that it won't turn on. While plugged in the battery will charge but it will not turn on.

Is it possible that I fried the motherboard when replacing the CPU Fan & Heatsink? I know with desktop computers you should wear a wrist strap connected to the metal of the case to prevent generating any static electricity. I didn't do this with the laptop because there wasn't a metal case for me to ground to. The laptop was plastic. So instead I stood barefoot on linolium in boxers while I worked on the laptop to prevent generating any static. I also thought that if I fried anything fixing the laptop,that It would happen right away, and I wouldn't have been able to use the laptop for hours afterwards.

I also made a rookie mistake and didn't wait long before putting it back together after I applied the thermal paste. There was only like a 30 min wait, which I figured would be sufficient time for the thermal paste to dry.

Is it possible that I fried the motherboard? Is there a way to know that's what it is for sure before I fork out the money to replace it? Are there any special methods I could use to turn the laptop on without using the power button (just to see if it's a faulty power button)? Is there something I can do to determine exactly what hardware is faulty? Any help would be highly appreciated.

 

[Hamperking68]

The chance of static electricity damaging the board is extremely low. Have you try re-seating the ram or discharging the CMOS battery?

 

[ffg7]

the fact it worked for 3hrs with no problems mean you didn't fry it. could try a hard reset by removing the main battery, disconnecting the power adapter & pressing the power button for about 10 seconds.

 

[rwolford87]

The chance of static electricity damaging the board is extremely low. Have you try re-seating the ram or discharging the CMOS battery?

I tried pulling the battery, and pressing the power button for a good 2 min at least. I haven't tried re-seating the ram though. I will try that. But I'm not exactly sure what u mean by CMOS battery. Could u please explain?

 

[rwolford87]

the fact it worked for 3hrs with no problems mean you didn't fry it. could try a hard reset by removing the main battery, disconnecting the power adapter & pressing the power button for about 10 seconds.

I did try the power button trick. I didn't get anywhere with that. I even held it for a few minutes trying to drain excess power. I'm going to try the few suggestions above. If that's not it I'm thinking it could possibly be the power button but, in order to replace that I have to replace the front shield with mouse pad and everything. Still turns out to be cheaper and a heck of a lot easier than replacing the motherboard. I didn't think it was possible to fry something and have it work for hours afterwards either. But, I am sort of a noobie when it comes to laptop parts replacement. This is the first one I've done but, I have worked on many other desktops.

 

[ffg7]

you haven't worked on enough desktop computers if you don't know about the cmos battery. all laptops\netbooks have 2 batteries, main battery to give portability & cmos battery to power the cmos which controls time\date & bios settings. all desktops only have 1 battery the cmos battery. use a volt meter to make certain the power adapter is still outputting the correct voltage. don't have to replace the "front shield with mouse pad and everything" to replace the power button as the power button is either part of the motherboard or on a daughter board connected to the motherboard via a ribbon or wire cable. check the dell site for the maintenance manual for that laptop as it will show you how to disassemble the laptop.

 

[Hamperking68]

Might just be worth double checking the cable that connects the power button to your mobo sometimes if the clips over a ribbon cable has not been secured properly the cable can become loose and fallout.