Why would my notebook only turn on after several attempts?

2

It was working perfectly fine until I changed it's Celeron processor for a Core 2 Duo today. Now it only turns on 1 out of 5 or 6 attempts. Sometimes at the 1st or 2nd attempt. It's pretty random by the way. This is what happens:

  1. I press the power button and I hear the fan and the LEDs light up. But it won't turn on. There's no beeps, no bios, not even screen backlight.
  2. I turn it off (by pressing the power button for ~5 seconds) and turn it on again, but still nothing.
  3. I repeat steps 1 and 2 until it finally turns on correctly.
  4. Once turned on it works perfectly fine: there's no lag, no overheating, no failures, nothing.

This also happens when I reboot it: it turns off normally but it won't turn on again and I have to repat steps 1 through 3 until I reach 4. Once it's on, it works perfectly fine.

Temp is about 48° Celsius when idle and maxing at about 71° (the sensors command says that critical temp. is +100°), so I don't think temperature is the issue. I've even tried letting it cool down completely but it doesn't make a difference.

Additional information:

The new CPU's FSB clock rate (800 MHz) isn't the same as that of my old processor (533 MHz), but as far as I know if that were the issue it shouldn't be able to turn on at all, no matter how many attempts I tried.

The lshw command indicates that I have a PM965/GM965/GL960 chipset, each one supporting an 800 MHz FSB, an 800 MHz FSB, and a 533 MHz FSB, respectively, according to what the Intel ARK pages say. So I don't know for sure which is the one that my motherboard has, since this processor has an 800 MHz FSB and it works fine once it has turned on. This is the output of lshw:

/0/100        bridge     Mobile PM965/GM965/GL960 Memory Controller Hub 
/0/100/2      display    Mobile GM965/GL960 Integrated Graphics Controller (primary) 
/0/100/2.1    display    Mobile GM965/GL960 Integrated Graphics Controller (secondary)

My notebook doesn't have any battery, so it's always running on the AC, in case you wonder.

Update:

It seems that the problem has somehow settled down: now only 1 out of 10 attempts fail. I still can't find any logical explanation for this.

arielnmz

Posted 2014-05-11T05:13:11.347

Reputation: 2 960

1What is the model of laptop? Did you check the compliance of CPU and motherboard? Did you check list of exceptions or errata or non-compliance with some chipsets? Are you able to check the previous CPU (if returned) work fine back again? Just in case, probably "walking contact" appeared somehow in there(or shortage). – Ruslan Gerasimov – 2014-05-11T10:41:46.700

Okay, I'll translate what I've found:

Since it has the GL960 chipset, it'd admit processors like Celeron M, Pentium Dual-Core with a FSB of 533 MHz. For example Intel® Pentium® Processor T2390 (1M Cache, 1.86 GHz, 533 MHz FSB)

Source: http://h30467.www3.hp.com/t5/Hardware-para-notebooks/Cambio-de-procesador-en-presario-c700-C792EM/m-p/238841/highlight/true#M26122

And I've found out that this Core 2 Duo T7500 has an FSB of 800 MHz. So why does it even turn on? Also, what does "walking contact" mean? Thank you!

– arielnmz – 2014-05-11T16:55:51.963

Also, the lshw command indicates a PM965/GM965/GL960 chipset, supporting an 800 MHz FSB, an 800 MHz FSB, and an 533 MHz FSB, respectively. So I don't know for sure which one is the one my motherboard has, since this processor has an 800 MHz FSB and it runs fine (except for the power-on). And another thing, my laptop doesn't have any battery so it's always running on the AC. – arielnmz – 2014-05-11T17:05:06.880

Sorry for reviving this post but for the record: it seems as if it works normally now, around 9 out of 10 attempts it would turn on normally, as if it had "settled down". Weird. – arielnmz – 2014-05-19T17:21:50.843

No answers