How to ”repair” a PC that suddenly changed to start with a black screen?

[Bengt T]

After long usage my PC, with Linux Mint 19.3, suddenly, from one day to an other, begun to boot slowly resulting in a black screen and an blinking cursor (underscore) in the upper left hand corner. There is no connection with the keyboard or mouse.

It is possible to access the a console after Ctrl-Alt-F1.

It is possible to access and login to the PC from a console of an other PC (via Ethernet and ”ssh -X...”). From the console of the other PC all directories seems ok and it is possible to start Firefox or Libreoffice with the presentation displayed in the ”console PC”.

It is also possible to boot from a DVD without any problem.

The SSD is far from full so lack of storage seems not be the problem.

From Googling I have found that many have experienced the same problem. However, from what I have found, always in conjunction with new installations.

Has anyone experienced the same problem as I have and, maybe, has a solution to suggest?

[Arlen Holder]

On Thu, 1 Oct 2020 06:10:22 -0700 (PDT), Bengt T wrote:

> Has anyone experienced the same problem as I have and, maybe, has a solution to suggest?

Certainly I have experienced the forever top-left blinking cursor
(and other blank-screen ills), as documented in gory detail here
(but for Windows, not Linux boots).
o Windows 10 BSOD indicates a hardware problem - but what hardware is the problem? <https://alt.comp.os.windows-10.narkive.com/oL7PTNKu/windows-10-bsod-indicates-a-hardware-problem-but-what-hardware-is-the-problem>
<http://www.pcbanter.net/showthread.php?t=1110105>

If you suspect hardware, this thread has gory details on making a
diagnostic boot USB via either Knoppix or Hirens Boot USB methods:
o Tutorial creating & using Hirens Boot CD & MemTest86 diagnostic stress
testing tools for USB boot to Windows 10 PE & WinXPmini on BIOS & UEFI
<https://groups.google.com/forum/#!topic/alt.comp.freeware/VWG0NNyGNHc>

That alone could take you a few weeks but if you still want more hardware
tests, this PC-centric diagnostic thread has a few more tests involved:
o What PC hardware diagnostic stress-testing freeware can you recommend?
<https://groups.google.com/forum/#!topic/alt.comp.freeware/dkkdOmL95d8>

[J.O. Aho]

On 01/10/2020 15:10, Bengt T wrote:
>
>
> After long usage my PC, with Linux Mint 19.3, suddenly, from one day to an other, begun to boot slowly resulting in a black screen and an blinking cursor (underscore) in the upper left hand corner. There is no connection with the keyboard or mouse.

Could it be related to system update? This quite common look when the
X11 fails to start for some reason.

> Has anyone experienced the same problem as I have and, maybe, has a solution to suggest?

Take a look in your /var/log/Xorg.0.log and see what it says.
I would guess there is an issue with the graphics driver, for example if
you use an older nVidia card and you been using the latest binary nVidia
driver, suddenly your graphics card has been removed from the current
driver, in a such case you need to switch to the latest legacy driver
and block the current driver.
Also kernel module version vs nVidia library version mismatch can cause
this kind of faults too.

You normally get a hint in /var/log/Xorg.0.log what it may be. Errors
begins with EE.
Run also dmesg and see if you have reoeating message about versions
don't match for your nVidia driver.

--

//Aho

[Bengt T]

The solution became to reinstall Linux Mint.

Thanks for your efforts.

[Daniel65]

Bengt T wrote on 04/10/20 03:51:

Bengt T, it has been several weeks since you came to this conclusion.
What has been the result??

The reason I ask is that I have been experiencing this same problem
(black screen with flashing cursor in top left corner) on this twelve
year old HP 6730b Laptop for a good twelve months ... maybe twenty-four
months. My work-around is to have a MageiaLinux 6.0 iso DVD in the DVD
Drive and boot up through the menu of that DVD to the (Spinning Rust, as
they say) Hard Drive Menu and make my selection and away I go.

I thought it might just be the button batteries with-in the Laptop case
going flat .... but have yet to open the case and stick in any of the
Button Batteries that I've brought!!
--
Daniel

[Carlos E.R.]

On 22/10/2020 12.44, Daniel65 wrote:
> Bengt T wrote on 04/10/20 03:51:

...

>> The solution became to reinstall Linux Mint.
>>
>> Thanks for your efforts.
>>
> Bengt T, it has been several weeks since you came to this conclusion.
> What has been the result??

He did not find a solution, he installed again.

>
> The reason I ask is that I have been experiencing this same problem
> (black screen with flashing cursor in top left corner) on this twelve
> year old HP 6730b Laptop for a good twelve months ... maybe twenty-four
> months. My work-around is to have a MageiaLinux 6.0 iso DVD in the DVD
> Drive and boot up through the menu of that DVD to the (Spinning Rust, as
> they say) Hard Drive Menu and make my selection and away I go.
>
> I thought it might just be the button batteries with-in the Laptop case
> going flat .... but have yet to open the case and stick in any of the
> Button Batteries that I've brought!!

The typical reason for a blank display with a not responsive cursor
blinking is failure to start graphics mode after an update to the
driver, as J.O. Aho explained.

I don't know exactly what symptoms a flat CMOS battery would have,
depends on each case.

--
Cheers, Carlos.

[Paul]

A flat CR2032 battery won't start. The hardware will refuse to start.
This seems to be a "feature" of the SuperIO, because the datasheet
for some SuperIO seem to have a VBAT connection as if the SuperIO
hardware monitor is measuring the voltage. However, the documentation
(hundred page datasheet) never mentions what the VBAT connection
is for.

From a hardware perspective, if the CR2032 is flat, the ORing diode
ensures no interaction where it counts. The +5VSB on the ATX supply,
provides VBAT power most of the time (so current is normally
not drawn from the CR2032), and the system really should have
started. It's only by nefarious means (motherboard design),
that you can knacker a system by sensing the battery is flat.
The design does not "inherently" pack up if the CR2032 is
not working. You can even run systems without a CR2032 in
the socket if you want. The exception would be these systems
that have added a check for no good reasons.

It's like the Dell systems, with the compression spring
fitting for the Northbridge heatsink. There are two electrical
connections, to the spring which keeps the heatsink on.
If the spring falls off, the computer won't start when you
press the button. Leaving this as one extra thing
for the poor user to investigate and repair. What this tells
you, is the clever engineers *knew* that spring would
not hold (we know why too), but instead of doing it right,
they just laid a booby trap across it :-) For some value
of "clever". The hooks have the wrong metallic finish
for proper soldering, and that's why they fall off.

There were features that did make sense. There was an AGP
slot protector added, to prevent the wrong AGP cards
from causing ruination. The feature blocks computer operation
until the newly inserted card is replaced with "something
that works". I specifically bought a motherboard with
that protection built in, at the time. For a while, the
circuit was equipped with a red LED, so the user would know
they'd made a mistake. Later motherboards saved $0.10 by
removing the LED and driver transistor (not so clever).

So yes, a flat CR2032 can stop a computer, but we don't
know why they set it up that way. No documentation. The CMOS
well that the VBAT powers, is isolated from the rest of
the Southbridge via transmission gates, and should have
nothing to do with breaking any SATA ports. You can't blame
"missing" hard drives on a flat CR2032.

Paul

[J.O. Aho]

On 22/10/2020 12.44, Daniel65 wrote:

> The reason I ask is that I have been experiencing this same problem
> (black screen with flashing cursor in top left corner) on this twelve
> year old HP 6730b Laptop for a good twelve months ... maybe twenty-four
> months.

If you have the flashing cursor, press alt-f1 to get to the first
console and be able to login with your user credentials.

take a look at your /var/log/Xorg.0.log for example:

less /var/log/Xorg.0.log

(to quit, just press q, pgup/pgdn to navigate)

now you should be able to read your log, the error tend to be in the end
of the file, so just press "end" or "pgdn" many times to get to the end
of the log.

The error should help you some or at least you can post it here, so
people has a chance to guess what gone wrong.

> I thought it might just be the button batteries with-in the Laptop case
> going flat .... but have yet to open the case and stick in any of the
> Button Batteries that I've brought!!

Won't make a difference, see Paul's reply.

--

//Aho

[Bengt T]

> Bengt T, it has been several weeks since you came to this conclusion.
> What has been the result??

> .......

My "solution" was to reinstall Linux with the same distribution and version as I had when the "black screen" problem appeared. This was easier and quicker for me, to get the PC back into operation, than trying to find the real reason behind the problem.

My PC has worked well since the re-installation. If the reason, in my case, would have been the battery, the problem should have come back, I guess.

[Carlos E.R.]

On 22/10/2020 14.13, Paul wrote:
> Carlos E.R. wrote:
>> On 22/10/2020 12.44, Daniel65 wrote:
>>> Bengt T wrote on 04/10/20 03:51:
>>
>> ...

A friend passed me the other day a Windows 7 laptop that would not boot,
with a battery that has been dead for ages. A Compaq.

The initial problem was that it needed to boot in repair mode, then it
would boot normally.

I booted a Linux on stick to do a SMART test of the hard disk and have a
look. I don't remember what I did first, the Linux test or the windows
repair.

Then I started to inspect things in Windows. Chrome would not start. I
tried to download Firefox or Chrome from the M$ browser: failure. I then
used an USB stick to bring in a browser and install it, and finally I
saw a message saying that the machine time/date was off by a lot which
impeded https to work. What? Then I noticed that the clock was off
indeed by years.

Even on automatics, Windows did not set the time on boot or even half an
hour later.

I commented to my friend about the date problem and she said that yes,
the computer failed to work until she corrected the clock manually every
day.

Thus, if it has an internal clock battery, it is also dead. I did not
open the machine. She is going to park it in a cupboard, she has a new
laptop with W10 and after a few days of resistance she is happy with it
(yes, I also installed a small Linux partition on it ;-) )

--
Cheers, Carlos.

[Daniel65]

J.O. Aho wrote on 23/10/20 01:20:

> On 22/10/2020 12.44, Daniel65 wrote:
>
>> The reason I ask is that I have been experiencing this same problem
>> (black screen with flashing cursor in top left corner) on this twelve
>> year old HP 6730b Laptop for a good twelve months ... maybe
>> twenty-four months.
>
> If you have the flashing cursor, press alt-f1 to get to the first
> console and be able to login with your user credentials.
>
> take a look at your /var/log/Xorg.0.log for example:
>
>
>

> (to quit, just press q, pgup/pgdn to navigate)
>
> now you should be able to read your log, the error tend to be in the end
> of the file, so just press "end" or "pgdn" many times to get to the end
> of the log.
>
> The error should help you some or at least you can post it here, so
> people has a chance to guess what gone wrong.
>

Thanks for this Aho and Paul.

Tomorrows the week-end, so I might be able to find a couple of minutes
to re-read your replies and I'll see if I can make some sense of less
/var/log/Xorg.0.log and get back to you.

Thanks.
--
Daniel