Mysterious issue preventing me from completing build :(

[harrisonjr98]

Hello all! Have a conundrum here and I’m really hoping to get help from somewhere as soon as possible so the machine in question doesn’t get written off and thrown into a closet for eternity.

 

Background, I’ll try and keep it short: I have an HP Omen Obelisk prebuilt with an i7-9700F and 2060.
 

My idea was to snag the 9700F for an upgrade to my personal rig, ship the 2060 to my brother as an upgrade for him, and then swap in an eBay i5-8500 and GT 640 (the hp mobo doesn’t have IGP outputs sadly) and give the HP concoction to my dad as a new office PC. Pretty simple right?

 

I did test the machine after buying it before stripping it apart, so I know that it worked in its original configuration. I can’t for the life of me get it to work now. I swapped in the i5 and GT 640 and powered it up. Windows was already installed on the SSD, and it blue screened instead of booting with the error “Machine Check Exception,” which Google tells me is when windows fails to “load any installed hardware or software.” Okay, I changed the hardware significantly, it’s probably just the windows install. Grabbed a known working bootable windows USB…. Same thing. Blue screened before I could even get to the options menu and tell it what I wanted to do. I thought the machine might’ve been ignoring boot order and going to the borked windows install, so I removed the SSD with windows on it and tried booting into the key again. Same error- “machine check exception.”

 

The weirdest part is, I can get into the UEFI just fine and it’s completely stable there. CPU and RAM both identify the properly. If there’s a way to identify GPU from the hp UEFI, I haven’t found it, but everything seems fine. Made sure to try both AHCI and legacy modes for my bootable installer.

 

My next thought was that maybe the PCIe slot-powered GT 640 wasn’t getting along with the machine, so I tried swapping in the ancient R9 280 from my personal rig and… can’t even get a video signal output from it, even though the fans spin up fine and the machine turns on without any beep codes or anything - a problem I didn’t even have on the GT 640! I was at least able to *see* that I was having issues! Ha.

 

So there’s no way to tell if it’s the GPU causing issues, because the only other GPU I have to swap in just doesn’t get along with this machine for whatever reason. I swapped it back to my personal rig and it outputs just fine.

 

So I’m at a total loss as to how to proceed at this point. I can’t get windows to behave on an SSD or even a bootable installer (which I know is good, I used it to install windows on another pc SINCE having this issue). I don’t know which of my two newly purchased hardware additions is causing the issue, if it even is either of them, and so I can’t proceed with returning either… just completely stumped where to go from here because I’ve basically tried everything.

 

ANY advice is massively appreciated at this point!!

[manikyath]

OEM boards tend to have poor cpu support, outside from the SKU's they are shipped with. i'd suggest checking the motherboard's documentation for CPU support.

 

HP's documentation tends to be quite good on that part, but for how good it is, it tends to be very hard to find...

[LateLesley]

Try booting it in safe mode, (CTRL+F8 before the logo, need to be quick) and boot in safe mode. That should avoid loading and drivers which might be upsetting it, and you can rip out the video driver, then try rebooting. At that point you can reinstall the driver for the GT 640.

 

Video drivers are one of the few drivers that can bluescreen the system, so it's probably that driver for your old card killing it. 

 

You may need to DDU the driver, before reinstalling the new one. 

 

https://www.guru3d.com/files-details/display-driver-uninstaller-download.html

[Deses]

Since you only tried with Windows, give Linux a go. Try booting into some Linux bootable USB like Ubuntu or Mint to see what happens.

 

2 minutes ago, LateLesley said:

Try booting it in safe mode, (CTRL+F8 before the logo, need to be quick) and boot in safe mode. That should avoid loading and drivers which might be upsetting it, and you can rip out the video driver, then try rebooting. At that point you can reinstall the driver for the GT 640.

 

Video drivers are one of the few drivers that can bluescreen the system, so it's probably that driver for your old card killing it. 

 

You may need to DDU the driver, before reinstalling the new one. 

 

https://www.guru3d.com/files-details/display-driver-uninstaller-download.html

I don't think that's the issue, he stated that even the Windows installer crashes.

[harrisonjr98]

16 minutes ago, manikyath said:

OEM boards tend to have poor cpu support, outside from the SKU's they are shipped with. i'd suggest checking the motherboard's documentation for CPU support.

 

HP's documentation tends to be quite good on that part, but for how good it is, it tends to be very hard to find...

Sure enough, if you look under "Processor upgrade information," the 8500 is absent. https://support.hp.com/us-en/document/c06124984

 

I found an 8400 locally for a good price which I am going to try next. I was under the impression that CPU compatibility was handled at the chipset level and thusly immune to OEM fuckery. Guess I was wrong? Still odd to me that the system appears to POST, and the UEFI recognizes it as an 8500 etc.

[LateLesley]

4 hours ago, Deses said:

Since you only tried with Windows, give Linux a go. Try booting into some Linux bootable USB like Ubuntu or Mint to see what happens.

 

I don't think that's the issue, he stated that even the Windows installer crashes.

Yeah, thats a fair point. trying Linux is a good shout. I'd be tempted to run a memtest86+ on it too. The fact the CPU is running makes me think it would be OK, BIOS's usually support CPU families, and usually it's a boot/no boot issue. Though sometimes the memory can be run over spec if the FSB speed is different, and that can cause weird issues. 

But the thought that crossed my mind when the CPU change then crashing was mentioned, was bent pin? It does happen sometimes. 

But yeah, running a live linux and seeing if it behaves or kernel panics, would be a good test. 

[harrisonjr98]

5 hours ago, harrisonjr98 said:

Sure enough, if you look under "Processor upgrade information," the 8500 is absent. https://support.hp.com/us-en/document/c06124984

@LateLesleyWhat's your thinking on this? It does seem that numerous skus that *should* be compatible on a chipset/socket level are excluded from HP's support list. My original thinking is that they only included skus that they shipped in their own systems with this mobo, but I don't believe they ever shipped both the F and non-F versions of the same sku on the Obelisk. I am going to try an 8400 tomorrow and will update the thread for anyone who stumbles upon it in the future to know whether it worked or not.

[LateLesley]

2 hours ago, harrisonjr98 said:

@LateLesleyWhat's your thinking on this? It does seem that numerous skus that *should* be compatible on a chipset/socket level are excluded from HP's support list. My original thinking is that they only included skus that they shipped in their own systems with this mobo, but I don't believe they ever shipped both the F and non-F versions of the same sku on the Obelisk. I am going to try an 8400 tomorrow and will update the thread for anyone who stumbles upon it in the future to know whether it worked or not.

Well. urgh - it's a difficult question to answer - there's many parts to the puzzle of if a particular CPU will work with a particular motherboard. I'll try and list them here, so you can get an idea of whats involved.

 

First is power - how much current the CPU uses, what voltage it needs, and this is handled by the VRM (Voltage Regulator Module). Lower spec CPUs (less cores and Frequency) don't need as much power as high end CPU's, and this is where a lot of pre-build manufacturers will cheap out, with less phases and lower power handling. So if you put a bigger chip in, it can overload the VRM. Sometimes to the point that bad things happen.

 

FSB & Memory Frequency - As you go up the CPU tiers, the CPU's can have faster Front-Side-Buses (FSB), and memory buses, but that is only part of the equation. The traces to the PCH and the memory play a part here, and poorly designed ones can't handle higher frequencies. So you may have a CPU with an 800MHz FSB and 1333MHz memory bus, and swap it for a newer chip with a 1066MHz FSB and can handle 1600MHz memory, but it doesn't work, because even if the CPU and Memory can handle those speeds, the motherboard might not and introduce problems. That's why folk start spending money on high end motherboards, proven to run at higher speeds. Pre-builds, not so much. 

 

Next is the BIOS - it needs to have the microcode programmed into it for the family of CPU you install. If it has, great, it has a chance of booting. If not, you're probably staring at a blank screen. Sometimes this can be fixed, if the motherboard manufacturer releases an updated BIOS with the newer microcode in it, but if not you are SOL.

 

Then if all that has worked out - you need to make sure the Memory can run at the speed the CPU wants to, sometimes you get odd situations where the CPU will handshake at a faster speed than the memory can handle, and on AIB boards (ASUS, ASROCK,EVGA,GIGABYTE etc) you can usually tweak timings and stuff, but OEMs like Dell and HP don't put those settings in the BIOS exposed to the user to change. 

 

So there's a few things that can affect whether a particular CPU is compatible or not. As you had the 8500 booting, it seems the microcode side of things is maybe ok, but the crashes could be power related, or maybe its a FSB issue or memory issue (Trying to run too fast). If you have access to settings for the CPU and memory speeds, you could try lowering them, and see if it stabilizes, and if so, the issue could lie with speed or power. 

 

As @manikyath said, going with a CPU of the supported list is best, but sometimes you can get lucky and run a CPU that is not on the supported list, especially if the board is a few years old, and newer lower power CPUs have come out. A good trick is to at least try and match the TDP with that of the old CPU, and the FSB speeds, then your chances of getting a new CPU to work is higher.

 

Now in your case you went from a i7 9700F to an i5 8500 so lets look at differences between chips. 

 

https://www.cpu-world.com/CPUs/Core_i7/Intel-Core i7 i7-9700F.html

https://www.cpu-world.com/CPUs/Core_i5/Intel-Core i5 i5-8500.html

 

so                                     9700F           vs       8500

FSB                               8GT/s DMI               8GT/s DMI    : both the same

Frequency                           3Ghz                  3Ghz             : both the same

Microarchitecture      Coffee-Lake             Coffee-Lake :both the same

Memory Support        DDR4-2666               DDR4-2666 :both the same

TDP                                  65W                        65W              :both the same. 

 

Only bit difference I see is the 8500 has integrated graphics, so you'd maybe need to make sure that was turned off in the BIOS if you have an external card. 

Looking at the specs, I'd rate the chances of the 8500 working as very high. Power shouldn't be an issue, neither should speeds etc, it's pretty much the same chip with 2 less cores. Since it's essentially a downgrade, it should have no problems running that chip. It may be worth just checking if there is an updated BIOS for your machine, and if there is, flashing it, as sometimes it can update microcode n stuff and support other CPUs. I think HP are pretty good at listing changes in their BIOS updates. 

 

Hopefully that's helpful. 

 

https://www.cpu-world.com/Compare_CPUs/Intel_CM8068403362607,Intel_CM8068403874523/

 

BIOS update info from HP.

https://support.hp.com/us-en/document/c00007682

Edited May 24, 2021 by LateLesley
Add HP BIOS Update Link

[Deses]

6 hours ago, harrisonjr98 said:

@LateLesleyWhat's your thinking on this? It does seem that numerous skus that *should* be compatible on a chipset/socket level are excluded from HP's support list. My original thinking is that they only included skus that they shipped in their own systems with this mobo, but I don't believe they ever shipped both the F and non-F versions of the same sku on the Obelisk. I am going to try an 8400 tomorrow and will update the thread for anyone who stumbles upon it in the future to know whether it worked or not.

Maybe they didn't try every single CPU of the family and only included in the list the ones they tested/ship, as you said. 

[harrisonjr98]

17 hours ago, LateLesley said:

Well. urgh - it's a difficult question to answer - there's many parts to the puzzle of if a particular CPU will work with a particular motherboard. I'll try and list them here, so you can get an idea of whats involved.

 

First is power - how much current the CPU uses, what voltage it needs, and this is handled by the VRM (Voltage Regulator Module). Lower spec CPUs (less cores and Frequency) don't need as much power as high end CPU's, and this is where a lot of pre-build manufacturers will cheap out, with less phases and lower power handling. So if you put a bigger chip in, it can overload the VRM. Sometimes to the point that bad things happen.

 

FSB & Memory Frequency - As you go up the CPU tiers, the CPU's can have faster Front-Side-Buses (FSB), and memory buses, but that is only part of the equation. The traces to the PCH and the memory play a part here, and poorly designed ones can't handle higher frequencies. So you may have a CPU with an 800MHz FSB and 1333MHz memory bus, and swap it for a newer chip with a 1066MHz FSB and can handle 1600MHz memory, but it doesn't work, because even if the CPU and Memory can handle those speeds, the motherboard might not and introduce problems. That's why folk start spending money on high end motherboards, proven to run at higher speeds. Pre-builds, not so much. 

 

Next is the BIOS - it needs to have the microcode programmed into it for the family of CPU you install. If it has, great, it has a chance of booting. If not, you're probably staring at a blank screen. Sometimes this can be fixed, if the motherboard manufacturer releases an updated BIOS with the newer microcode in it, but if not you are SOL.

 

Then if all that has worked out - you need to make sure the Memory can run at the speed the CPU wants to, sometimes you get odd situations where the CPU will handshake at a faster speed than the memory can handle, and on AIB boards (ASUS, ASROCK,EVGA,GIGABYTE etc) you can usually tweak timings and stuff, but OEMs like Dell and HP don't put those settings in the BIOS exposed to the user to change. 

 

So there's a few things that can affect whether a particular CPU is compatible or not. As you had the 8500 booting, it seems the microcode side of things is maybe ok, but the crashes could be power related, or maybe its a FSB issue or memory issue (Trying to run too fast). If you have access to settings for the CPU and memory speeds, you could try lowering them, and see if it stabilizes, and if so, the issue could lie with speed or power. 

 

As @manikyath said, going with a CPU of the supported list is best, but sometimes you can get lucky and run a CPU that is not on the supported list, especially if the board is a few years old, and newer lower power CPUs have come out. A good trick is to at least try and match the TDP with that of the old CPU, and the FSB speeds, then your chances of getting a new CPU to work is higher.

 

Now in your case you went from a i7 9700F to an i5 8500 so lets look at differences between chips. 

 

https://www.cpu-world.com/CPUs/Core_i7/Intel-Core i7 i7-9700F.html

https://www.cpu-world.com/CPUs/Core_i5/Intel-Core i5 i5-8500.html

 

so                                     9700F           vs       8500

FSB                               8GT/s DMI               8GT/s DMI    : both the same

Frequency                           3Ghz                  3Ghz             : both the same

Microarchitecture      Coffee-Lake             Coffee-Lake :both the same

Memory Support        DDR4-2666               DDR4-2666 :both the same

TDP                                  65W                        65W              :both the same. 

 

Only bit difference I see is the 8500 has integrated graphics, so you'd maybe need to make sure that was turned off in the BIOS if you have an external card. 

Looking at the specs, I'd rate the chances of the 8500 working as very high. Power shouldn't be an issue, neither should speeds etc, it's pretty much the same chip with 2 less cores. Since it's essentially a downgrade, it should have no problems running that chip. It may be worth just checking if there is an updated BIOS for your machine, and if there is, flashing it, as sometimes it can update microcode n stuff and support other CPUs. I think HP are pretty good at listing changes in their BIOS updates. 

 

Hopefully that's helpful. 

 

https://www.cpu-world.com/Compare_CPUs/Intel_CM8068403362607,Intel_CM8068403874523/

 

BIOS update info from HP.

https://support.hp.com/us-en/document/c00007682

Wow, that's a lot of fascinating info! Thanks. For my part, the local 8400 I found worked just fine, so either HP mobos are very particular about skus even within supposedly compatible generations, or the 8500 I had was broken. Thanks all for the brainstorming!

[LateLesley]

2 hours ago, harrisonjr98 said:

Wow, that's a lot of fascinating info! Thanks. For my part, the local 8400 I found worked just fine, so either HP mobos are very particular about skus even within supposedly compatible generations, or the 8500 I had was broken. Thanks all for the brainstorming!

You are more than welcome. I'm glad you got it going with the 8400, You may be right about the MB being very particular, i've come across that in the past with thinkpad laptops and WiFi cards - they only whitelisted a few models, and would refuse to work with anything outside of that. Another wee trick that some OEMs pull to make sure you go back to them for their overpriced spares. 

 

https://medium.com/@p0358/removing-wlan-wwan-bios-whitelist-on-a-lenovo-laptop-to-use-a-custom-wi-fi-card-f6033a5a5e5a

 

Anyway, glad it's all sorted. 

[harrisonjr98]

2 hours ago, LateLesley said:

You are more than welcome. I'm glad you got it going with the 8400, You may be right about the MB being very particular, i've come across that in the past with thinkpad laptops and WiFi cards - they only whitelisted a few models, and would refuse to work with anything outside of that. Another wee trick that some OEMs pull to make sure you go back to them for their overpriced spares. 

 

https://medium.com/@p0358/removing-wlan-wwan-bios-whitelist-on-a-lenovo-laptop-to-use-a-custom-wi-fi-card-f6033a5a5e5a

 

Anyway, glad it's all sorted. 

It's a bit beyond my knowledge level technicality-wise, but there was discussion a while back when AMD was going to cut b350 support for zen 2 and people were up in arms about it. It was something concerning physical storage size limitations accounting for more skus - or like, there was leniency in the spec about how much storage was required and so mobo manfacturers ran with it to save a buck - something like that.

 

It's beyond my knowledge level, as I said - but that was my first awakening to the idea that that was even a thing- being able to white/blacklist certain skus from a manufacturer-to-manufacturer level. It blew my mind that this wasn't locked, purposefully or otherwise, at a chipset level, to prevent consumer confusion.

 

I'd almost guarantee that HP did internal validation on the skus they planned to ship with this mobo, and maybe a couple of likely upgrade choices, and then blacklisted the rest and called it a day.