Why won't this new motherboard boot to bios?

[TC_12345]

I have received a replacement motherboard for dell inspiron n5110 and it will not boot to BIOS, i have tried with two different motherboards after thinking the first one i got sent was faulty but the same thing happens on the replacement board i received.

I have changed the CPU, the power-board daughterboard and put a new RAM module in.

I have noticed that the I/o daughter board which i have not replaced yet gets very hot to the touch on some of the copper bits where the screw holes are. They are marked as 'H1' etc. I was getting four beeps which indicated there was a problem with the ram, so i bought a new compatible 4gb ram stick and put in which stopped the beeps, but still no display, so i then proceeded to connect the i/o daughter board (the one that gets hot) and after i done this the beeps returned indicating there is a problem with the RAM. This board connects to the part right next to where the RAM slots are, would this board be causing a short in some way, or does it sound like it is ruining the memory slots?

Also there is a hall sensor which is connected to the motherboard, would a problem with this part cause this type of issue as i have no experience with hall sensors.

Thanks

 

[wmauctions]

Have you tried hooking your laptop to an external monitor?? it might be loading if the screen is bad??

just a suggestion!

 

[TC_12345]

Hi, thanks for the reply.

Yes i have it connected via vga into the external monitor all the time for testing purposes.

I have the motherboard stripped down to just the basics. CPU & RAM. I just find it suspect that the daughter-board gets so hot, and it connects to the motherboard right next to where the ram slots are.

I have a third replacement motherboard on the way now along with a new daughter-board as well, so i am hoping this will do the trick. Maybe i have just been unlucky and have been sent defect motherboards.

The thing is, it does give me beep codes which makes me wander if the board itself is OK. But i have tried everything i can think of in terms of testing.

The fan starts up for a few seconds then dies out, then it comes on about 3-4 minutes later, i guess just because the CPU is warming up.

I will wait and see if the new motherboard & i/o board will work. If not then i really am stumped as to what it could be.