Question PC won't start ?

[Ferencvaros1899]

Hi. Sorry for my English.

I put together a new computer with a specialist at a large electronics store and picked it up from the courier yesterday.

Yesterday I installed Windows, drivers, programs. It ran for several hours without problems, turned it off in the evening. This morning I started it up, after 1 second it shut down, tripped the breaker. I can't even turn on the circuit breaker when PSU plugged into the socket. There are 3 phases in the house 3x16 amps, I moved it to another room with another phase, it cut it off immediately. I did not use any other electronic devices when I tried to start the computer. My old machine works without problems so what could be the problem with this new build?

CPU: Ryzen 9800 X3D
GPU: RTX 5070 Ti
PSU: Asrock Steel Legend 1000 W 80 plus Gold

​

 

[DaleH]

Hi. Sorry for my English.

I put together a new computer with a specialist at a large electronics store and picked it up from the courier yesterday.

Yesterday I installed Windows, drivers, programs. It ran for several hours without problems, turned it off in the evening. This morning I started it up, after 1 second it shut down, tripped the breaker. I can't even turn on the circuit breaker when PSU plugged into the socket. There are 3 phases in the house 3x16 amps, I moved it to another room with another phase, it cut it off immediately. I did not use any other electronic devices when I tried to start the computer. My old machine works without problems so what could be the problem with this new build?

CPU: Ryzen 9800 X3D
GPU: RTX 5070 Ti
PSU: Asrock Steel Legend 1000 W 80 plus Gold

​

Is there a switch on the power supply where one can switch between source volages?

 

[Ferencvaros1899]

Is there a switch on the power supply where one can switch between source volages?

No, just Fan Control mode switch

 

[CountMike]

Hi. Sorry for my English.

I put together a new computer with a specialist at a large electronics store and picked it up from the courier yesterday.

Yesterday I installed Windows, drivers, programs. It ran for several hours without problems, turned it off in the evening. This morning I started it up, after 1 second it shut down, tripped the breaker. I can't even turn on the circuit breaker when PSU plugged into the socket. There are 3 phases in the house 3x16 amps, I moved it to another room with another phase, it cut it off immediately. I did not use any other electronic devices when I tried to start the computer. My old machine works without problems so what could be the problem with this new build?

CPU: Ryzen 9800 X3D
GPU: RTX 5070 Ti
PSU: Asrock Steel Legend 1000 W 80 plus Gold

​

Obviously bad PSU or it's power cable. Even powerful PSU draws about 2-5 A so amperage shouldn't be a problem

 

[Misgar]

This morning I started it up, after 1 second it shut down, tripped the breaker.

The PSU might have died, but if your circuit breakers are particularly sensitive, they may be tripping on the initial high current surge that affects most switched mode PSUs. This lasts for a few milliseconds when power is applied to the PSU and the 400V DC bulk electrolytic charges up.

As an example of high inrush currents, here is a 550W PSU tested on Toms.
https://www.tomshardware.com/reviews/asus-tuf-gaming-550w-bronze-power-supply-review/2

"Inrush current, or switch-on surge, refers to the maximum, instantaneous input current drawn by an electrical device when it is first turned on. A large enough inrush current can cause circuit breakers and fuses to trip. It can also damage switches, relays, and bridge rectifiers. As a result, the lower the inrush current of a PSU, right as it is turned on, the better."

When used on a nominal 115V 60Hz AC mains supply, the current spike for this 550W PSU was 78.580A. On a nominal 230V 50Hz AC supply, the surge was 93.990A. Neither figure are good. Better designe PSUs have lower surges.

Some 16A house circuit breakers can cope quite happily with a 79A/94A surge, other more sensitive breakers might trip.
https://electrical-engineering-portal.com/lv-circuit-breakers-essence

"As a general rule, curve C circuit breakers are used for standard distribution applications. If there are high inrush currents, curve D avoids false tripping."

Note: If the breaker that trips is rated at 16A and is curve C, replacing it with a 16A curve D breaker might fix the problem. Get a qualified electrician.

All of the above is immaterial if your brand new PSU has died violently.

 

[shaester_123]

The PSU might have died, but if your circuit breakers are particularly sensitive, they may be tripping on the initial high current surge that affects most switched mode PSUs. This lasts for a few milliseconds when power is applied to the PSU and the 400V DC bulk electrolytic charges up.

As an example of high inrush currents, here is a 550W PSU tested on Toms.
https://www.tomshardware.com/reviews/asus-tuf-gaming-550w-bronze-power-supply-review/2

"Inrush current, or switch-on surge, refers to the maximum, instantaneous input current drawn by an electrical device when it is first turned on. A large enough inrush current can cause circuit breakers and fuses to trip. It can also damage switches, relays, and bridge rectifiers. As a result, the lower the inrush current of a PSU, right as it is turned on, the better."

When used on a nominal 115V 60Hz AC mains supply, the current spike for this 550W PSU was 78.580A. On a nominal 230V 50Hz AC supply, the surge was 93.990A. Neither figure are good. Better designe PSUs have lower surges.

Some 16A house circuit breakers can cope quite happily with a 79A/94A surge, other more sensitive breakers might trip.
https://electrical-engineering-portal.com/lv-circuit-breakers-essence

"As a general rule, curve C circuit breakers are used for standard distribution applications. If there are high inrush currents, curve D avoids false tripping."

Note: If the breaker that trips is rated at 16A and is curve C, replacing it with a 16A curve D breaker might fix the problem. Get a qualified electrician.

All of the above is immaterial if your brand new PSU has died violently.

Wow . Nice . Graphs have made me grasp concepts I never thought I would be able too . The trick is too look at it like a puzzle .

I'm tipping my hat here .

 

[Misgar]

If you have 20 minutes to spare, read this thread about someone with a similar breaker tripping problem on a new PC.
https://forums.tomshardware.com/thr...hen-using-new-pc.3880349/page-2#post-23499539

The cost of getting an electrician to fit new breakers seemed prohibitive, so I suggested a high quality Tripp-Lite surge protector with inductors (coils/chokes) to limit current surges. See my entry at 10:57AM on Thursday, April 19 in the link above.
https://www.amazon.ca/Tripp-Lite-ISOBAR4ULTRA-Isobar-Protector/dp/B0000513O4

This link includea a diagrammatical representation of voltage spikes, superimposed on a sine wave mains supply voltage waveform.
https://www.electronics-tutorials.ws/resistor/varistor.html

The Tripp-Lite certainly isn't cheap, but sub-$40 surge arrestors normally provide protection against nothing more than voltage spikes using an MOV (Metal Oxide Varistor). They do nothing to limit the high inrush current surge into an ATX PSU.

In my opinion, really cheap surge arrestor strips are pointless, because many ATX PSUs already include an MOV. A cheap arrestor strip just adds another MOV to the circuit, completely failing to tackle the current surge problem. You might get slighly more protection against lightning strikes with a second MOV.
https://www.electronics-tutorials.ws/resistor/varistor.html

For more information about ATX PSU internal mains filtering and protection:
https://www.techpowerup.com/articles//overclocking/psu/160/3

This image of an ATX PSU shows an MOV (large blue disc) to limit voltage spikes and a Thermistor (green disc) to limit current surges. The blue rectangular component next to the thermistor is a Relay to bypass the thermistor after the initial current surge is over.