Out of the blue, my 4 year old self built sim PC is no longer starting up.  I switch it on at the mains, the fans and CPU water pump all start spinning but then they all go off again.  At this point I'd press the power button on the PC itself, but that does nothing, does not even spin the fans up.  In order to try to book again I have to power off at the mains and plug in again.  However that results in the above.    All lights look normal on the motherboard itself, when it does try to start the monitor never wakes up, so I don't even get a bios screen.

I've tried:

• Changing the graphics card to a spare;
• Changing the Power Suppoy to a spare;
• Re-seating all motherboard components;
• Booting without any internal cables (e.g. USB, SSD) attached;

I've not tried removing the NVMIe card and booting because those screws are a fiddle.  Not sure what else to try as I've no spare parts to try to isolate to motherboard, RAM or CPU.

Anyone been down this road before with these symptoms?  How does the BIOS communicate a fault these days (Asus Pro Gaming Z170)?  I remember in the "olden days" it used by be a speaker and you'd have to find out what the sequence of beeps where.  However my modern case does not have a speaker.

Thanks for any thought on this

Simon

Have you tried replacing the CMOS battery 4 year old.

Also check your manual some older boards you move a jumper to clear the CMOS newer boards have a button.

Edited January 20, 20206 yr by rjfry

Had a similar problem two months ago. Seems your MoBo is dammaged.

Ed

Quick test - Remove RAM and GFX card and boot up. If the board is working, it will make BIOS-Code beeps to tell you the RAM is missing.

If there are no beeps, then the board probably needs replacing. Reset the BIOS via the Jumper to check the board.

7 hours ago, flying_w said:

I switch it on at the mains, the fans and CPU water pump all start spinning but then they all go off again.  At this point I'd press the power button on the PC itself, but that does nothing, does not even spin the fans up.

It may be that the power button has a problem. Most modern motherboards have a "power on with keyboard" (or similar) setting in the BIOS which is often on by default. Have you tried starting it from the keyboard? Just press a key when it's plugged into the mains.

Edited January 20, 20206 yr by vortex681

Many tanks for all of the suggestions.

After taking out the RAM and GPU, I received one long beep and two short beeps at the next power up.  Consulting the internet I understand that to mean "RAM problem".  Furthermore I noticed on my mobo I have four little LEDS, marked CPU, RAM, GPU and one other I forget.  During power up, the CPU lit up the went off, the RAM LED did the same and then the power went off.  The GPU led and the other LED were never lit.  As I have tried two different GPUs, I don't think it's getting as far as the GPU before it powers down again.  Most likely cause at this time, my RAM or the Mobo circuitry associated with that.

As I don't have any spares, my inclination is to buy one stick of the cheapest RAM compatible and see if that rescues the machine.  If it does, I can go forward from there.  I don't want to buy a like for like replacement or better until later in the year, when the entire system is due an upgrade (and at which time the hardware requirements for the new MS FlightSim may be known)

Any comments?

Thanks
Simon

Your system should boot with one stick of ram, I don't know the MB you have try one stick in a different slot you may have a MB problem and not ram one.

None of the RAM sticks would work in any slot, even just one and following the layout in the Z170 user guide 😞

1 hour ago, flying_w said:

None of the RAM sticks would work in any slot, even just one and following the layout in the Z170 user guide 😞

I think your looking like a new MB.

I probably am, in which case I'll see how the 2nd user availability is looking for a like for like swap.