MSI K9N Neo V2 and AMD Athlon 64 X2 5400+ won't start after BIOS update

I have a PC which is configured on MSI K9N Neo V2 motherboard and it previously came with AMD athlon 4200+ installed on it. It was running fine with stock BIOS. Now purchased a brand new AMD Athlon 64 X2 5400+ processor. Before installing it I have updated the BIOS to v2.90. Then installed new processor and then heatsink over it with new thermal paste. Connected the power cable and press the power button but the system won’t boot at all. It even didn’t show me the BIOS Screen. Why?

It seems to me that you have done an incomplete BIOS update. Any unsuccessful BIOS update on motherboard can cause the motherboard to brick completely. I mean it will destroy or corrupt the BIOS chip, processor or whatever it may thus making the whole system no longer bootable and respond to any action. In that case you either need to replace the motherboard with a new one or send it for RMA if it still having a warranty. Otherwise you can contact the any specialist to replace the BIOS chip and flash with a new BIOS version. This could bring back the life of the motherboard. Actually I had run the same version of BIOS on four different motherboard along with AMD Athlon 5600+. I didn’t get any problem yet.

The motherboard would not be in contact processor. You have to once again verify the installation of CPU; the CPU socket 939/AM2 must be pressed hard during that lowered the matient. Otherwise, you need to test the CPU on some other compatible motherboard. Did you try replacing the PSU? 19 amps are definitely not enough. And since there are no power supply brands such as Corsair, Enermax and Tagan, it is questionable whether the 19 amps can be supplied stably. Here a Corsair VX450 would do well.

I have a MSI K9N Neo V2/V3 board. The latest bios is actually is v 2.4. If you are updating, it will fix many problems but I recommend that when you do with the program of the MSI Live update 3. This little program takes care of bios update by downloading it.