[SOLVED] Peculiar CMOS

[Gazpacho Soup!]

Hi All,

I’m sorry to be one of those people who only posts when when they get stuck, but I am well and truely stuck!

I have an HP spectre x360 running windows 10, which suited me very well until my son got overexcited watching old episodes of robot wars and excitedly stamped on it (it was a Hypnodisc match, so fair enough).

Although it still worked, the screen was cracked, so I bought a second hand one on evil-bay and dismantled the laptop to fit it. Trying to fix it - with my limited knowledge - is probably

All went well until I turned it on and got a CMOS checksum error (502). The machine then booted but neither the keyboard, touchscreen nor touchpad worked. I duly attached USB keyboard and mouse, which did work, and set about trying to repair whatever was wrong.

I have not suceeded.

I am not very very skilled with computers, and trying to do this myself was perhaps foolhardy. However I have learnt a little along the way and, to my little brain and based on what I read, the issues experienced seem quite unusual:

First off, neither the keyboard, touchpad nor touchscreen work in windows or in BIOS.
This I understand might lead one to suspect hardware problem, however I think hardware is ok; all were working fine before, the keyboard has power (one key illuminates briefly at startup) and, bizarrely, the touchpad work in the very narrow instance of when the machine is in the HP recovery programme.
I have tried reflashing the BIOS and the UEFI with latest HP offerings, but makes no difference.
i have also tried updating the drivers for all thre and this makes no difference (although, notably, the touchscreen has disappeared from device manager)
I have even done a complete reinstall of windows 10, but still I can only use an external mouse and keyboard.

I’ve now reached the end of my admittedly limited repertoire of skills. The one thing I would like to try but can’t is clearing the CMOS, however I don’t see how I can. These machines have no CMOS battery and the clearing method instead involves holding down two keys during startup (which I cannot do, becuase you have to do it before the USB keyboard initialises).

I am well and truely stuck. Help!
Tom.

 

[kerberos_20]

are u sure all flex cables are connected properly?

 

[Gazpacho Soup!]

Hi Kerberos

Visually they seem fine yes. I would suspect them too were it not for the fact that
A) the screen displays fine - it just doesn’t work as a touch screen
B) the trackpad does work fine when the HP recovery mode is on

it’s as if the CMOS error has stopped all human interface devices from working

 

[iPeekYou]

This sounds dumb,....but have you tried reconnecting the old screen? Then maybe limp through the CMOS clearing procedure with a cracked screen. Afterwards, reconnect the eBay screen and see where it lands you.

I share your vigour in foolhardy and janky attempts to fix things, and that might be the first thing I'd do in your situation. Electronics are weird, perhaps HP uses the same boneheaded approach like Apple where swapping components from another unit will cause some strange behaviour (like how switching cameras from one iPhone X --or 12, can't recall --will cause the camera to stop working entirely on both phone).

 

[Gazpacho Soup!]

Ipeekyou: I wondered that too, about the protectionist approach adopted by apple, but some searching suggests they do not (and this laptop is four years old).... yet, at least.

I therefore actually did reconnect the old screen yes but problems with keybord, mouse and screen all persisted (whereas previously the old screen had touch).

This therefore leads me back to my original concern that some in BIOS/CMOS is awry. I find it most frustrating that there is seemingly no way to clear the CMOS if your keyboard doesn’t work. If that were the problem, so annoying that it’s comparatively minor yet seemingly so intractable in this instance.

 

[iPeekYou]

Ipeekyou: I wondered that too, about the protectionist approach adopted by apple, but some searching suggests they do not (and this laptop is four years old).... yet, at least.

I therefore actually did reconnect the old screen yes but problems with keybord, mouse and screen all persisted (whereas previously the old screen had touch).

This therefore leads me back to my original concern that some in BIOS/CMOS is awry. I find it most frustrating that there is seemingly no way to clear the CMOS if your keyboard doesn’t work. If that were the problem, so annoying that it’s comparatively minor yet seemingly so intractable in this instance.

Hot diggity damn....I can imagine your frustration. I do agree that HP's approach to clearing CMOS is stupid and takes no account into complete (onboard) peripherals failure. Given that they also have desktop motherboards you'd think they'd implement an onboard clear CMOS solution.
Assuming we are correct to pursue the CMOS problem, seems like other than connecting another OEM, laptop keyboard to your laptop you're forced to use external peripherals.
My other guess is that some connections got short when the laptop is taken apart, causing the HIDs to go awry. But even then, that's an edge case and not like there's much we can do either way.

 

[Gazpacho Soup!]

Well I’m not giving up quite yet, and it’s just got a little more complicated...

I asked the who I bought the screen from whether it came from a damaged laptop and he said the cpu died but everything else seemed fine.

Then, as he seems to know a thing or two, he suggested I check both the BIOS and the ‘embedded controller’. A little digging reveal the circuit diagram below, which suggests there is a separate chip (it8977, bottom left) that holds separate instructions for connecting HID devices. This chip apparently does not get flashed when BIOS upgrades (unless anyone knows better?), meaning it could be my problem. I can even see these chips on eBay, but it looks like one needs a special device to flash them.

tom

 

[Gazpacho Soup!]

Sorry forgot diagram

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[Gazpacho Soup!]

Maybe I need to move this to motherboard discussion??? Mods?

 

[iPeekYou]

Well I’m not giving up quite yet, and it’s just got a little more complicated...

I asked the who I bought the screen from whether it came from a damaged laptop and he said the cpu died but everything else seemed fine.

Then, as he seems to know a thing or two, he suggested I check both the BIOS and the ‘embedded controller’. A little digging reveal the circuit diagram below, which suggests there is a separate chip (it8977, bottom left) that holds separate instructions for connecting HID devices. This chip apparently does not get flashed when BIOS upgrades (unless anyone knows better?), meaning it could be my problem. I can even see these chips on eBay, but it looks like one needs a special device to flash them.

tom

Yeah, you probably do need a flashing tool and some mechanism to interface with it. The software is most likely proprietary so slim chance we can find it online.

Personally I still won't pursue the fact the chip's firmware on yours suddenly going corrupt.... I'd probably try with another Spectre X360 keyboard first before delving into parts and software that are difficult to procure.

Good luck to you, man. I fear I've exhausted my troubleshooting capability.