Question Very long time to POST (Lenovo Z50-70)

[alipmcg]

Hello, I have a Lenovo Z50-70 laptop that has been exhibiting strange behaviour for the last year or so. From a powered off state, pressing the power button causes the fan to come on, and the battery, charging and Num Lock lights to come on, but then it sits with a blank screen for anywhere between 1 and 8 hours before reaching POST (or maybe I should 'before completing POST'). Once it has booted, it behaves completely normally, including entering and waking from Sleep mode.

I've tried attaching an external screen and it displays nothing. I've tried disconnecting the battery, hard drives, RAM, wireless adapter, keyboard and trackpad, and none of it made any difference.

Does anyone have any idea what could be causing this? I suspect the CMOS battery, but from what I've read, that would usually reset the system clock, which isn't happening.

Thanks in advance for any help

 

[Lutfij]

With the external and internal power disconnected, have you tried pressing and holding down the power button for at least 30 seconds? That usually drains all stored charge as well as static build up. If you suspect the CMOS battery playing up, does the time on the system while in BIOS show up right? If the time/date are off then yes the CMOS is at fault, otherwise it's possible that the ram or storage or your OS might be the culprit.

Speaking of culprit, might want to cross reference Lenovo's support site to see what BIOS updates are available.

 

[alipmcg]

With the external and internal power disconnected, have you tried pressing and holding down the power button for at least 30 seconds? That usually drains all stored charge as well as static build up. If you suspect the CMOS battery playing up, does the time on the system while in BIOS show up right? If the time/date are off then yes the CMOS is at fault, otherwise it's possible that the ram or storage or your OS might be the culprit.

Speaking of culprit, might want to cross reference Lenovo's support site to see what BIOS updates are available.

Thanks for your reply. Yes, I have tried holding the power button down for a minute or so with battery & charger disconnected, it didn't help.

Getting to BIOS is a problem, because the laptop can take up to 8 hours to get to the Lenovo splash screen, and when it does I only have a few seconds to press F2. I did manage it once though, and the system clock was correct, and the BIOS is also the most up to date. I would like to try re-flashing the BIOS, but it's so hard to get into it.

Like I said, I tried removing RAM and storage and it didn't help, and since the problem occurs at POST regardless of whether a boot drive is connected, I don't think the problem is with the OS.

 

[alipmcg]

With the external and internal power disconnected, have you tried pressing and holding down the power button for at least 30 seconds? That usually drains all stored charge as well as static build up. If you suspect the CMOS battery playing up, does the time on the system while in BIOS show up right? If the time/date are off then yes the CMOS is at fault, otherwise it's possible that the ram or storage or your OS might be the culprit.

Speaking of culprit, might want to cross reference Lenovo's support site to see what BIOS updates are available.

Hi, in case you're interested, the laptop eventually stopped booting at all and I sold it for spares and repairs. The guy I sold it to had another identical model with a damaged screen so he just wanted the chassis to put his mobo in, and he sent me a photo of the faulty mobo that he took out of my laptop. Whoever replaced the CPU (I bought it refurbed) had let thermal paste leak around the socket, and this had eventually caused some damage. Pretty amazing it worked for 4 years like that huh?