Bios battery replacement?

[tony draper]

Having a bit of trouble with the Draper home made super puter,suspect the motherboard or the bios ,what is involved in replacing the Bios battery?,can one simply howk out the old one and stick in a new without it completely porking the machine,I remember flashing the bios on a machine years ago and that process was accompanied by many dire warnings.
Not just guessing here,the machine hangs at a certain point at bootup if I poke the battery with my finger it complets the boot up quite happily,also it refuses to use a graphic card in the PCI Express slot insisting on only using the on board graphic chip.
:uhoh:

[Parapunter]

I'm sure an answer will be along shortly. Meanwhile, try looking in the BIOS for your gpu settings. Some mobo's will set the gpu to onboard by default. If you can change the setting, your graphics card should show up as normal.

[Saab Dastard]

Tony,

First port of call is the manual for your mobo, to check for specific procedures about replacing your CMOS battery - e.g. any jumpers or DIP switches that need to be reset.

If it's a standard Li-ion coin cell battery you shouldn't have any problems - be careful with any delicate clips and ESD, of course. Best to use a plastic object to prise it out - and avoid magnetised objects for the task!

Replacement batteries are easy to source online (less easy to find in your local Boots or hardware store, though you might be lucky). All coin cells have the type engraved on them which makes it easy to get the right replacement.

If you haven't already lost all the BIOS settings, note them down before removing the battery (although it sounds like you have, with your PCI Express problem) - otherwise the system will revert to defaults.

I'd be a bit concerned about the need to poke the battery, though - that sounds like a poor connection rather than flat battery.

SD

[tony draper]

Built a puter for a mate of mine a few years back and he began to have similar probs,ie time and date showing silly things various bits of kit in the PCI slots not working then wokring fine at next bootup,it was the bios battery with a iffy connection,so I soldered a new one in,you could do that with motherboards int olden days.
No information at all about replacing the Bios battery in the manual which in truth does not have a great deal of information on anything.
Checked the bios for graphic boot priority and have it set for PCI Express then on board chip, actually this does not seem to make any difference,as it did not matter which monitor socket was used both work or rather should I say both used to work.
:uhoh:

[Saab Dastard]

Tony, at least replacing the CMOS battery is a quick and cheap step - if it works, great, if not you've only spent a couple of quid.

I'm in the process of doing just that with my laptop - the time is back to 1980 so it's definitely a dead CMOS battery. It also has a problem with the main battery no longer charging at all. But first off, I'm going to see if changing the CMOS battery will get it to charge the main battery. I'm not hopeful, and expect to have to shell out £40 or so on a replacement, but you never know.

SD

[jimtherev]

Lots of MoBo's use 2032 coin batteries. I've got a couple of boxes of 'em (don't ask!) well in date. Pm me and I'll send you one if you like. Well worth giving the holder a bit of a poke to tighten it up while you are doing the change... hopefully you won't have to get the soldering iron out this time.

Don't worry about losing your settings: looks as tho' you already have done so, & that's why the BIOS doesn't recognise your graphics card any longer. Just hit <del> when booting up and reset all to your liking.

Usual dire warnings about earthing yourself & using non-metallic pokey things apply of course.

[green granite]

Some MBs suggest that you change the battery with the power on so as not to loose the settings.

Windows should see the graphics card as a new hardware device every time it starts unless you've turned off plug 'n' play. I suspect you might have an intermittent connection somewhere and not necessarily the battery, when you press the battery you are also flexing the MB. :(

[tony draper]

yer I figured that Mr G,think I will just get a new MB they's cheap enough now,component on modern MB now are so tiny and the tracks so complex I would not dare put a soldering iron anywhere near em now.
Machines ticking away ok at the mo but having me posh I gig super duper graphic card not working is getting on me tits.
:uhoh:
Thanks for the help chaps

[Saab Dastard]

Some MBs suggest that you change the battery with the power on so as not to loose the settings.

As I've been reading around this topic ('cos I have to actually change the battery on my laptop), I've got the impression that on most (all?) newer MOBO's, the BIOS data is stored in flash RAM, so the CMOS battery is only used for the RTC. Therefore BIOS settings should not be affected at all by removing the CMOS battery.

I haven't found a definition of "newer", though, so I'm not sure whether this means 5 years, 10 years or what! The laptop is about 7 years old, Compaq pre-HP purchase.

SD

[mcdhu]

Mr Draper,

I know nothing about computers but have just successfully replaced my 2032 batt in my Dell Dimension because the date/time started to drift off when it had been unpowered for a while.

It was straightforward - power off, ping it out, ping the new one in - job done. All I had to do was tell it the date and time. I has written down the BIOS settings, but I hadn't played around with them so I had nothing to reenter. The only danger was 'pinging' the old one out without damaging any of the surrounding hardware or wires.

Good luck,
mcdhu

[mikeddavies]

The BIOS (basic input/output system) is now normally stored in flash RAM, allowing updating by "flashing", unlike older types which were ROM or EPROM. However, the variables - clock, date, boot sequence, onboard video or video card etc are stored in CMOS which is maintained by the 'coin cell' battery, commonly 2032 - if this is old or there is a fault on the motherboard which discharges it then the variable settings will be lost. Simply replace the battery, power the system up and enter the BIOS when booting - a message appears briefly- usually hit Del or F1 - during the boot sequence, and set the variables. Then SAVE the changes and exit.
Good luck

MikeD

[tony draper]

One is pleased to report the Draper home made super puter is all hunky dory now,one changed the Bios battery and lo everything including the PCI express is ticking away fine now.
Thanks for the help chaps:ok: