When I turn on the PC, it turns on and off intermittently

[hurr]

Good afternoon,

I have an Asus P7P55 motherboard with an Intel Core i5 processor, 4x 2Gb RAM, 1Tb Seagate HDD connected via SATA and a DVD burner connected via SATA as well.

The thing is, I removed the HDD to put it in a case and turn it into an external HDD, but without formatting or anything, I copied some data and put it back in the case.

I reconnected the SATA and power to the HDD and powered on the power strip and the UPS, I thought the power supply was turned off with the switch but it wasn't.

When I turned it on, the power supply and processor turned on for a few seconds and then turned off, and after 8 seconds or so it turned on and off again, and it does this successively.

The motherboard has power and I've tried disconnecting the HDD and DVD reader and it does the same thing. I've also tried bridging the power supply and it works.

It seems like the motherboard is broken but I don't see anything strange or swollen, plus it's connected to a UPS and it would be strange if a voltage spike had broken it.

I've removed the CMOS battery and the problem persists when I put it back.

To turn it off, I either cut the power or keep the power button pressed, both work so I doubt the switch is faulty.

I haven't touched anything, I just removed the HDD and put it back, so I doubt the CPU cooler is faulty and it's overheating, even so I've looked and touched it and everything is fitted properly, like the day before before it gave any error.

I must say that this computer has never failed me in 4 years and it usually stays on 24h a day 7 days a week.

Do you think it's the motherboard or can I try something else before buying a new one?

Thanks.

[Espinetenbolas]

@hurr:

When you press the power button, the power supply and the processor turn on for a few seconds and then turn off, and after 8 seconds or so, it turns on and off again, and it does this successively.

It looks bad for the motherboard (short, BIOS corruption or something that is not visible at first glance has crashed) but it could also be that the power supply is not supplying some voltage correctly, so it turns on and off because the motherboard detects something abnormal in the supplied voltages.

@hurr:

The motherboard has power and I have tried disconnecting the HDD and DVD reader and it does the same thing. I have also tried bridging the power supply and it works.

The fact that the power supply starts up is not indicative and 100% sure that it can be ruled out, the thing would be to test the power supply on another working computer or try your computer with another power supply.

@hurr:

It seems that the motherboard is broken but I don't see anything strange or swollen, besides it is connected to a UPS and it would be strange that a voltage spike would have broken it.

It looks like it, but I wouldn't rule out the PSU... as I said, test both separately.

@hurr:

I haven't touched anything, I just removed the HDD and put it back, so I doubt that the CPU cooler is bad and it's overheating, even so I have looked and touched it and everything is well fitted, like the day before before it gave any error.

Great mysteries of computer science.

@hurr:

Do you think it's the motherboard or can I try to test something else before buying a new one?

The problem is that if you buy a motherboard and it's the PSU that's bad and if you buy a PSU and it's the motherboard also bad... my recommendation is that someone lets you have a PSU that works perfectly to rule out... this way you make sure that it's the motherboard's fault.

[hurr]

It's the work PC so on Monday I'll try to get another source and test it as you tell me.

Thank you very much, I'll comment on what happens.

[hurr]

Well, the same thing happens with another source :facepalm:

I've tried disconnecting everything and it only starts by removing the P2 from 12V. But when I reconnect the P2, the same thing happens again.

So I guess the board is gone.

Can you tell me a current board that I can replace this one with?

Right now it has a P7P55 LX socket 1156.

Thanks.

[Espinetenbolas]

@hurr:

Pues nada, con otra source ocurre lo mismo :facepalm:

He probado a desconectar todo y solo arranca quitando el P2 de 12V. Pero cuando vuelvo a conectar el P2 vuelve a pasar lo mismo.

Mal asunto.

@hurr:

¿Podéis decirme una placa actual por la que pueda sustituir ésta?

Ahora mismo tiene una P7P55 LX socket 1156.

No hay nada nuevo, el 1156 está descatalogado… lo único que vas a encontrar es de segunda mano y te va ser dificil porque a todos les pasará como a ti... peta la placa pero el micro está intacto por lo que quien quiera estirar el equipo tiene un problema a la hora de buscar estos componentes.

En función de la prisa que tengas o de lo potente que fuera tu micro puedes elegir dos opciones:

1ª - Comprar un micro y una placa nuevos. (es lo más rápido pero también lo más caro, puedes vender el i5 pero antes seria conveniente verificar que realmente funciona bien y la placa no se lo ha cepillado)
2ª - Buscar una placa de segunda mano (con el riesgo de que su vida util esté a punto de finalizar pueden ser meses, un año o 5, todo dependerá del uso que le dieron y del que le des)

No se, yo personalmente elegiria la uno porque es lo facil, lo rapido y lo que menos historias pero cada uno tiene unas prioridades o formas de hacer las cosas.

Otra opción es que hables con ASUS a ver si tienen en stock una P55 pero eso si que seria una movida carisima por los gastos de envio... la veo poco factible pero por enviar un e-mail al fabricante no se pierde nada.

[hurr]

Thank you very much for everything.

I have left the equipment at the service center where we bought it in 2010 and we will see if they can check it to confirm that it is the motherboard.

If it is irreparable, they will give me a quote for either a new motherboard and processor or a motherboard that they still have in one of their warehouses.

For now, I will say goodbye, but if they fix it and the problem is something else, I will write again. If I don't give any news, it is because I have had to take one of the 2 options you mentioned.

Goodbye.

[rul3s]

Oh, well I just thought about it and I have a new 1156 motherboard from Trinca at home, if you send me a PM! I've wanted to put it up for sale for a while now but I never remember xd