Question Pc turns on and off repeatedly.

[MyNameJeff123]

Hello,
Started building a pc for my sister yesterday with the following specs:

CPU: i5 7400 [re-used from old build]
MOBO: Msi z170a [re-used from old build]
RAM: 4x4gb ddr4 [re-used from old build]
GPU: Gigabyte GTX 1650
1x Sata SSD
1x Sata HDD
PSU: Corsair CV550

The parts that are being re-used all worked before and even worked when i tested this build outside the case. Put it all in the case and suddenly the pc wouldnt turn on anymore. I turn it on, all the fans spin, the mobo lights up, not a second later it shuts down again and repeats that loop after 1-2 seconds.

Things i've tried:
Tested with my own PSU -> Same problem.
Swapped RAM around to all slots -> same problem, also occurs without any RAM installed.
Jumped JBAT1 for a cmos reset -> didnt work.
Pulled cmos battery out for a good 30 minutes -> didnt work
Checked for bent pins -> Pins look fine.
Checked for burned VRM's -> VRM's look normal
Took everything out and built it up again outside the case -> still the same problem.

Whats interesting is that when you pull the CPU 8 pin and leave the 24pin it actually does start up, as in, the fans stay on and the mobo stays lit up.

Does anyone know whats going on? I dont have another intel cpu or lga1511 board laying around to test cpu or board.

Thanks in advance.

 

[rocktalkrock]

What BIOS version does your motherboard have? It needs at least version "7976v1H" to support the i5 7400 CPU.

 

[MyNameJeff123]

What BIOS version does your motherboard have? It needs at least version "7976v1H" to support the i5 7400 CPU.

I dont know exactly what BIOS is on there, When i got the board originally it needed a bios update. got that done in the store and after it worked good for 3 years until i switched to ryzen last summer. Now im trying to reuse the board with the same cpu and same RAM but this issue came up

 

[rocktalkrock]

I dont know exactly what BIOS is on there, When i got the board originally it needed a bios update. got that done in the store and after it worked good for 3 years until i switched to ryzen last summer. Now im trying to reuse the board with the same cpu and same RAM but this issue came up

Have you tried booting with no drives connected to see if you can get into the BIOS?

 

[MyNameJeff123]

Have you tried booting with no drives connected to see if you can get into the BIOS?

It gets nowhere close to that. everything powers off within a second. With the entire system turned off, with all but CPU and RAM disconnected. even with no RAM. The only way i can get it to actually not power off is when you disconnect the CPU power cable. But obviously you are not gonna get very far without a CPU.

 

[rocktalkrock]

It gets nowhere close to that. everything powers off within a second. With the entire system turned off, with all but CPU and RAM disconnected. even with no RAM. The only way i can get it to actually not power off is when you disconnect the CPU power cable. But obviously you are not gonna get very far without a CPU.

You have a Slow Mode Booting Switch located at the bottom of your motherboard labeled "SLOW_1", is it set to Enabled or Normal (Disabled)? Have you tried both settings?

 

[Plumms]

Hello,
Started building a pc for my sister yesterday with the following specs:

CPU: i5 7400 [re-used from old build]
MOBO: Msi z170a [re-used from old build]
RAM: 4x4gb ddr4 [re-used from old build]
GPU: Gigabyte GTX 1650
1x Sata SSD
1x Sata HDD
PSU: Corsair CV550

The parts that are being re-used all worked before and even worked when i tested this build outside the case. Put it all in the case and suddenly the pc wouldnt turn on anymore. I turn it on, all the fans spin, the mobo lights up, not a second later it shuts down again and repeats that loop after 1-2 seconds.

Things i've tried:
Tested with my own PSU -> Same problem.
Swapped RAM around to all slots -> same problem, also occurs without any RAM installed.
Jumped JBAT1 for a cmos reset -> didnt work.
Pulled cmos battery out for a good 30 minutes -> didnt work
Checked for bent pins -> Pins look fine.
Checked for burned VRM's -> VRM's look normal
Took everything out and built it up again outside the case -> still the same problem.

Whats interesting is that when you pull the CPU 8 pin and leave the 24pin it actually does start up, as in, the fans stay on and the mobo stays lit up.

Does anyone know whats going on? I dont have another intel cpu or lga1511 board laying around to test cpu or board.

Thanks in advance.

To me this sounds like you need to reseat the Processor. Just a hunch though. Possible that you need to ensure standoffs are installed properly too so that nothing is being shorted near the CPU.

 

[MyNameJeff123]

To me this sounds like you need to reseat the Processor. Just a hunch though. Possible that you need to ensure standoffs are installed properly too so that nothing is being shorted near the CPU.

Ye i already tried reseating it once, no good. It also doesnt work on a cardboard box so I dont see how shorting is causing the issue either. Will try reseating the CPU again tonight although i doubt its gonna work.

 

[MyNameJeff123]

Ye i already tried reseating it once, no good. It also doesnt work on a cardboard box so I dont see how shorting is causing the issue either. Will try reseating the CPU again tonight although i doubt its gonna work.

Yea as expected it didnt solve the issue :/