On Tuesday, 28 November 2023 15:49:10 GMT Daniel Frey wrote:
> On 11/28/23 03:38, Michael wrote:
> > Over the last 8-9 months I noticed an old Lenovo G505s laptop is spending
> > a
> > long time in the POST process, before eventually the OEM logo shows up on
> > the screen.  Last time I timed it, it took 2.5-3.0 minutes.  Normally it
> > would only take ~20-30 seconds.  Once the logo shows up the boot process
> > proceeds without further delay.
> > 
> > Initially, this delay to POST would happen randomly and rarely.  Now it
> > happens every time.
> > 
> > Things I tried:
> > 
> > 1. Reflashing the UEFI firmware - it didn't work because it already has
> > the
> > latest firmware.
> > 
> > 2. Removing the main battery and holding down the power button for 15
> > seconds, hoping to reset the firmware.
> > 
> > 3. Leaving the PSU cable connected overnight.
> > 
> > 4. Testing the RAM and HDD.
> > 
> > None of the above improved the situation, or indicated what might be
> > wrong.
> > 
> > I'll reseat the RAM sticks and the HDD next, in case a contact is
> > oxidised,
> > but what else could cause this noticeable delay to POST?  A failing RTC
> > CMOS battery?
> 
> We have had a few of these at work and these symptoms were cured by a
> new CMOS battery. The voltage on the battery has likely dipped to
> 2.9-3.0 volts; they get unreliable then (i.e. it's dead.) If you leave
> it long enough you'll start getting RTC errors on POST.
> 
> I'd try that first, assuming you can still get the CMOS battery for these.
> 
> Dan

Thanks Dan, will do.  I was planning to take it apart soon to replace the HDD 
with an SSD, so this would be the first thing to check.  I expect finding a 
replacement unit will be difficult.  Every Lenovo RTC battery seems to have a 
different part number.