Baffling flashing cursor problem after POST

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Baffling flashing cursor problem after POST

Postby califauna » Fri May 25, 2018 3:26 am

Hi,

Recently I got a BSD crash while using the PC. Since then I've had a flashing cursor in a black screen at top left corner of screen after POST. Prior to that I got a couple of other BSDs which I was unable to attribute to anything. Unfortunately no crash dump file was saved for unknown reasons (dumps are enabled).

It appears to be something to do with the motherboard, as even with nothing attached except a bootable usb flash drive which works on other PCs, I still get the cursor.

Before testing with a usb drive I tried a bunch of stuff:
-tested power supply to hard drive by powering up hard drives using power supply then connecting them via sata adapter to other PCs. The drives can then be read on the other PC.
-changed ram sticks and slots
-tried different sata ports on motherboard. Including the Marvel 6Gb controller ports, j-micron 363 ports, and ICH10R southbridge controller ports.
-cleared CMOS, reset BIOS, remove and put back battery, switched to other BIOS (the motherboard has option of switching between two onboard bios).
-disabled all onboard devices and tried with BIOS configures for IDE.
-tried with other video card and other video card slots
-disconnected everything from board except boot device being tried.

At boot the motherboard LEDs light up as normal and then go off as they should. It does hang a little longer on the 'boot device' LED though, and 4 very faint beeps coming from the board (not the drives) which don't sound like the normal loud POST beep which indicates for example when no CPU fan is connected (I'm using a fanless heatsink)

Any drives attached are detected in BIOS in the 'sata configuration' section and in the 'boot devices section', but regardless, after POST I get the flashing cursor.

I recently switched to an SSD from mechanical. At first I was thinking maybe the southbridge or another sata controller got fried by the traffic, but after trying using the ports of all three sata controllers on the board (confirmed separate chips for each one) I suspected more the BIOS chips. There are however 2 separate BIOS chips on the board, which I have switched between, re-flashed the BIOS for each, removed and checked contacts etc.

Any ideas welcome before I have to send to ASUS to see if they can repair it. Wont be a warranty to repair though so looking to diagnose and if possible repair myself.

Rampage 3 Extreme Motherboard
Intel 980 Extreme CPU
Various drives tried
EVGA 750 p2 power supply.
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Re: Baffling flashing cursor problem after POST

Postby Karlsweldt » Fri May 25, 2018 7:44 am

Likely not an issue, but do an inspection of all larger capacitors on the motherboard. If any have domed tops, lean excessively or show leakage, that could be a reason. Should be repaired by a pro, if so.
Seems the bootstrap is hanging on finding a bootable path. Ensure you have only the main bootable media listed.. the hard drive, optical drive and one other. Any other drive will auto-detect. Check that the "search other bootable media" (or so worded) is enabled. Don't use a network boot path unless required!
For using other than the primary SATA data ports, ensure you have the RAID configuration set to 'auto' or 'JBOD' instead of any RAID class.
You might want to create a USB bootable drive, basic only, and use that as the only bootable path. If that still gives the same problem, then likely some damage has been done to the North Bridge chipset. "Legacy" USB feature has to be enabled.
Did note some listings for that EVGA 750 p2 PSU having problems. Do a voltage check on the main ATX power connection, any black lead as common. All voltages should be within 2% +/-, 1% is ideal. The -12 volt source can be off by 3% and still be viable.
A link to the main ATX pinout is here.. https://engineering.purdue.edu/ece477/A ... es/ATX.pdf
The "power OK" lead should show the same as the +5 volt source, only present as a signal when the PSU has stabilized. More than .2 volts lower, the system may not show life signs.
The "PS on" lead will show near +5 volts when the system is off, and near or at zero volts when operating.
The "+5 volts stand-by" will show +5 volts whether the PSU is active or not, as long as mains power feeds the unit.
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Re: Baffling flashing cursor problem after POST

Postby califauna » Fri May 25, 2018 12:32 pm

Thanks.

I have tried a couple of basic bootable pen drives which work with other PCs.

I have also tried with another working power supply already but will check output on PSU.

I suspected chip damage to the board as the BSODs started within a month of starting to use an SSD as did this boot fatal problem, which came immediately after a BSOD, all of which seems quite alot to be coincidence to me.
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Re: Baffling flashing cursor problem after POST

Postby Karlsweldt » Sat May 26, 2018 8:45 am

You may need to activate the AHCI feature for use with the SSD drive. Some motherboard designs work better with it, some without. Ensure that the first addressed SATA port hosts the OS drive.
Very unlikely that a hard drive of any kind would cause damage to the data bus, unless some unwanted "tinkering" were done to the drive. Regular hard drives have separate power and data connectors. Laptop drives do have a combined power/data link on one connector. But that is polarized, fits only one way.
I would reset all BIOS pages to default, then redo each page as to how the system is configured. If no 100% reset, then disconnect the PSU input, do a few tries at starting to drain reserves. Then remove the BIOS battery and leave for about 5 minutes. The CLR CMOS jumper should be set before removing the battery. Possibly some feature is cross-matched in the IRQ/DMA assignments. The BIOS does the initial assignment of features, then the OS does the final assignments. Sometimes the OS gets a bit whimsy and changes settings in the BIOS that it should not.
Not common for a virus to hit the BIOS settings, but still a chance. Maybe a check to ensure all is good? This link should refer to most OS versions.
https://answers.microsoft.com/en-us/win ... c0c6b3a32c
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Re: Baffling flashing cursor problem after POST

Postby Mr T » Tue May 29, 2018 3:50 am

Looks like board may be shot. If you cannot boot from USB and the RAM, PSU, Video card and PSU check out (ie work on a known working machine), points to board or CPU - remove heat sink and fan and CPU. Check for bent or missing pins in the CPU socket and give it a good clean up. Re-seat it if all looks OK and test again. If still the same issue, it will be motherboard, I wouldn't even bother contacting ASUS, just either get a new board, or use it as a chance to upgrade.... :)
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Re: Baffling flashing cursor problem after POST

Postby califauna » Thu May 31, 2018 3:52 am

The PC is now working. For posterity sake and any others who may have these symptoms, yesterday I put another CPU which I bought cheap into the PC and it worked and since then no problems so far. So I'm assuming something went bad with the CPU and this was the cause of all the above.

Would nevertheless be interested to hear any speculations on what fault with a CPU could cause such a strange set of symptoms , where it POSTs OK and passes the MB CPU test, and gets into BIOS, but cant find any bootable devices.

After testing with the new CPU (XEon 5502) which worked , I then put the old one (i7 980x) back in again, which again didn't work.

Xeon 5502 is back in and working fine again now.

NO other components or configurations were changed while testing the chips.

Whether its entirely down to the CPU or something to do with the interaction of the CPU and some other component I don't know, but whatever it is, I can say for sure that it's something to do with the CPU, because this is the only thing being changed.

A thought - perhaps one or more of the cores are bad but one or more of the cores are still good, and POSTing and BIOS relies a different set of cores to the bootstrap process?
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Re: Baffling flashing cursor problem after POST

Postby Karlsweldt » Thu May 31, 2018 5:04 am

Deleted your previous posting, almost identical to the last one. Duplicate posting is frowned on.
Good that you have a working system again. Possibly something failed in one of the cores or on-die features. Always best to consult the QVL list and compatibility list for what is certified to work best. Goes for memory modules also. With the newer on-die memory controller feature, lower voltages are specified for memory chips to properly page.
The 'i7 980' version of CPU is listed as compatible..
https://www.asus.com/Motherboards/RAMPA ... pDesk_CPU/
The POST process works in an entirely different realm from the OS. Two different environments. From simple BASIC to complex commands when the bootstrap is enacted.
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Re: Baffling flashing cursor problem after POST

Postby califauna » Thu May 31, 2018 12:08 pm

Karlsweldt wrote:Deleted your previous posting, almost identical to the last one. Duplicate posting is frowned on.
Good that you have a working system again. Possibly something failed in one of the cores or on-die features. Always best to consult the QVL list and compatibility list for what is certified to work best. Goes for memory modules also. With the newer on-die memory controller feature, lower voltages are specified for memory chips to properly page.
The 'i7 980' version of CPU is listed as compatible..
https://www.asus.com/Motherboards/RAMPA ... pDesk_CPU/
The POST process works in an entirely different realm from the OS. Two different environments. From simple BASIC to complex commands when the bootstrap is enacted.


Yes sorry about the double post. There was an approval delay but I couldn't remember if I'd posted or not and couldn't find any notification.

Yes I checked the CPU compatibility list when I started using the chip maybe 2 or 3 years ago. It was seemingly going fine for all that time. Could be just coincidence, but then SSD comes along and the crashes started within 2 or three weeks.

Will run this cheap CPU for a while just to check that whatever the cause was its not something that's going to keep frying CPUs, or doing whatever it is that caused the 980x to stop working.
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Re: Baffling flashing cursor problem after POST

Postby Karlsweldt » Fri Jun 01, 2018 8:03 am

Don't worry about double posting. Happens to all of us, one time or another. Likely just a data glitch in the sending/receiving of the post. If no desired results, refresh the page or renew the page link. Should be there. Been there, done that.
One main problem with CPU failure is that the heat sink cannot transfer waste heat efficiently, and parts of the CPU die overheat. There are thermal sensors in the CPU die as well as close to the belly of the CPU, and if temperatures rise too high, the CPU throttles back. And may initiate a forced shut down of the system. CPU to heat sink contact should be tight, with minimal thermal paste between them to effect the optimal transfer of waste heat. That thermal paste compound can dry out a bit after a few years.. becoming less efficient.
Seriously doubt the SSD drive initiated the problem. Just coincidence. The hard drive controller system is managed from a secondary chipset, the South Bridge, which manages all the I/O and storage channels. All data then passes through the North Bridge, sort of a main traffic hub.
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Re: Baffling flashing cursor problem after POST

Postby Mr T » Sat Jun 02, 2018 12:15 am

Extremely rare for a CPU to go bad, but it does happen.. It won't be anything you have done unless you fitted incorrectly (forced it in/bent pins/crushed it with heatsink). Is it still under warranty?
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