Computer Related > Boot problem Computing Issues
Thread Author: James Loveless Replies: 13

 Boot problem - James Loveless
After some advice, please. I know only a little about computers.

Machine is a PC from 2015. Windows 10, Version 20H2. Over the last few weeks when I boot from cold, I get a screen with various info, ending with:

Chassis intrude! Please check your system
Fatal Error... System Halted

This just hangs there and the machine doesn't continue.

If I press the reset button on the PC, it successfully boots and everything works.

I'm worried that at some point the PC may not boot at all.
 Boot problem - smokie
It's telling you that someone has opened the computer case (or it thinks they have).

So check it's all screwed up properly first.

From memory you can usually turn off detection in the BIOS which means hitting a key sequence during boot to get into it then finding the setting and disabling it.

Do the visual check first then come back with the make/model of your computer and someone will help you get into the BIOS.

It's unlikely to be terminal.
 Boot problem - James Loveless
Many thanks.

There are four big screws on the outside at the back and they are tight. I did open the case a year or so ago to clean out some of the dust, but was sure to tighten everything up afterwards. Or is there something inside that may need tightening?

The machine is a custom build from PC Specialist Limited.

The motherboard is Asus X-99A. ACPI BIOS Revision 1801. No idea if any of that is relevant.
 Boot problem - No FM2R
Have you moved the computer, banged it, or anything like that?

You cna safely ignore it unless it irritates you. Then, as Smokie says, repeated pressing of F1 (probably, but might be F2, F10 etc.) will get you into the BIOS and then under Security you can hunt down that parameter and switch it off.
 Boot problem - smokie
It might need the onboard jumper removing to disable, see how you get on.

If nothing has changed and the machine is 6 years old it could conceivably also be a failing CMOS battery on the motherboard, though in my experience this more commonly throws a date/time request screen at boot. They aren't expensive or hard to change.
 Boot problem - James Loveless
Not sure what an onboard jumper is.

I've vaguely heard of the CMOS battery, though not sure if I could find it.
 Boot problem - James Loveless
No, it hasn't been moved/banged. It sits in the same place all the time, behind the monitor. I plug/unplug a USB wire for an external hard disk for backup every day and that's it.

Thanks for the tip about where to find the setting to turn it off. I'm relieved that I will still be able to go on using the machine. I have a horror of it failing.
 Boot problem - tyrednemotional
Chassis intrusion detection usually relies on a physical switch which is thrown when the case is opened. Frankly, they're more often fitted on machines for business use than those for personal use (which doesn't mean to say you won't have had one fitted).

The switch would be a simple intrusion switch with a connection to the appropriate header (pins) on the motherboard. An example of one is as follows:

www.ebay.co.uk/itm/Genuine-Dell-0UC635-Chassis-Intrusion-Sensor-SFF-Dell-Optiplex-745-755-760-/252455452691

.....though design will vary, as will the positioning, but it should be obvious when the case is opened (if fitted).

That particular Asus motherboard has a header that can be disabled by means of a "jumper" - this is a small connector that simply fits over two of the pins, and shorts them out, or it can indeed be disabled via BIOS settings.

If it is a valid alarm, then neither the jumper has been fitted (or left in place) nor has the detection been disabled in BIOS. As I said above, it is by no means certain that yours didn't have intrusion detection, but I find it less likely on balance that it would.

I do wonder whether the CMOS battery comment might be relevant (as a low battery would cause a potential loss/non-memory of certain settings). In particular, the motherboard documentation contains "A message appears when you connect the sensor or switch for the first time or when you reconnect the sensor or switch to the chassis intrusion connector. Reset the system to exit the message".

You are obviously doing the above, and it is working at least once, but obviously being repeated.

I think if you're up for it there is a three-part action for this:

i) Open the case and check if there is in fact an intrusion detection switch (it will be intended to be held "off" by the part of the case you remove)

ii) Check the chassis intrusion header (to which the above should be wired if it exists) to see if there are loose wires, or if no switch exists, to check for existence of a jumper. If you do want to do this, it will be a visual check with the case open, and it should be possible to post a link to a diagram of where to check.

iii) Check the BIOS for the enabling/disabling of chassis intrusion checking. Bios is entered using "DEL" at startup on this board. I would suggest that you could do this check if you are careful (and change the setting if necessary), but you will need guiding through the pages. (It isn't under "Security" (no criticism of Mark - I looked there first - it's under some miscellaneous settings in the "Monitor" menu.)

If all of those look OK, then I'd go with the suggestion of changing the CMOS battery (which isn't difficult, but as above, the usual first sign of it being low is date/time issues).
Last edited by: tyrednemotional on Sat 13 Mar 21 at 17:55
 Boot problem - James Loveless
Huge thanks for this.
 Boot problem - tyrednemotional
This link might well be interesting (though I'd do the three steps above before replacing CMOS battery).

tp69.blog/2018/02/21/chassis-intruded-fatal-error-system-halted/

If you do want to do the replacement, there will be a number of people on here that have done it, and give quick encouragement.
 Boot problem - James Loveless
Having read the above (thanks again, TnE) I think my situation might suggest a failed CMOS battery, as I'm in the habit of switching the machine off at the wall every night (except if it's grinding away on a Windows update or whatever) and therefore the PC has no mains power for maybe 8/9 hours in 24. This has been going on ever since I got it - therefore over six years.
 Boot problem - tyrednemotional
Not a difficult item to replace, and it looks very accessible and obvious on that board.

It will be (99.9%) a CR2032 as in the above link. It may need levering slightly to remove it - I tend to use something non-conductive like a cocktail stick.

If you go for it, ground yourself beforehand by touching the case for a few seconds. (and patently, the machine should be off and unplugged)

Be aware that you will lose BIOS settings if/when the battery is removed.

On first subsequent startup, you will need to set date and time again, and I suggest you go through the "load optimised defaults" path to get things back working.

BIOS is entered by pressing "DEL" repeatedly during startup, (it may just enter it anyway after battery replacement) and neither of the above should require any deep knowledge - The manual doesn't describe setting date and time, but my guess is that it is done by clicking on the "settings wheel" next to the date/time display on the prime BIOS screen - take care with date (it may not be DD/MM/YY format in BIOS, and 12/24hr clock). After you've set that, you can elect to load optimised defaults as you exit (menu item).
 Boot problem - Zero
Not seen a PC with a chassis intrusion switch for decades. Thought they went out in the early 90s.
 Boot problem - smokie
My mobo has the jumper and setting but the case doesn't. I guess that's how many are.
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