Repeating characters in ubuntu 20.04 boot - character

There are some repeating characters when my ubuntu 20.04 is booting, like [[^~[[^~[[^~ ... it seems like someone is pushing specific buttons but pushing buttons doesn't write anything when I try. Also sometimes when I'm writing something my keyboard starts repeating 0, and it stops when I push another button. I think it may be related to that problem. Is that a software bug or a hardware problem? What should I do? I add a picture of that. My laptop model is Lenovo Ideapad 520. (about three months ago I spilt a cup of tea on my laptop but these problems appeared recently, I'm not sure if they are related)
Console Screenshot

this is most likely a direct issue of you adding tea to your keyboard.
I have previously worked with repairing computers and sometimes a customer could tell you they dropped a glass of water in their keyboard a year ago and one day the computer couldn't turn on or their keyboard didn't work correctly.
without going into an over technical explanation, this is something that happens, and when you spill water in your computer (or any other type of liquid) the connectors and fuses in the board might get damaged and it can take a while before the problems start showing.
you can do 2 things, if possible you can deactivate the keyboard on your laptop and buy a USB keyboard and use that, which might work forever or to some other water related problem occurs.
The best solution is to bring your laptop to a computer repair service and tell them what happened, they'll be able to pull it apart and look for damage and might be able to just clean it with isopropyl and save it that way, or they will be able to tell you what to do.
Really depends on your budget and the age of the laptop tbh as depending where you live the repair can be costly.

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Hyperpixel 4.0 strange behaviour of Touch driver error

I since a few months, I have been using a Hyperpixel 4.0 Touchscreen with my Raspberry 3B+ without any problems. Since a few weeks i use my touchscreen with the Raspberry Pi 4 Compute module and mounted both on my own designed PCB. Unfortunately, I’m facing some difficulties with the Touch function of my Hyperpixel 4.0. I have no clue how to solve these problems because the circumstances, which cause the fault don’t make sense to me.
Which System do I use?
Hyperpixel 4.0 in combination with Raspberry ComputeModule 4 with 2GB RAM and 8GB onBoard eMMC. Both is mounted on my custom PCB, which is supplied with 24V, stepped down by an «APP63300WU-7» Step down converter, which provides 3A # 5.1V continuous output. The measured Voltage over 2 Days of measurement is a maximum of 5.2V and a minimum of 5.05V. The software ist the latest Raspbian.
What error is caused?
I have been running a GUI on my Raspberry Pi. I have one Page on which i have three sliders for changing brightness of my room light, colortemperature and one slide is to regulate the speed of some fans. Everything works fine in darkmode, but if I change to lightmode and touch the screen for about 1.5 seconds, the touch- function hangs up. My GUI doesn’t move anymore and I have a still image. I know that it’s only the touch function beacause if I plug in a keyboard and mouse, I can open for example chromium or other stuff without problems. With «i2cdetect »-command I can detect the Goodix GT911 driver on Address 0x14. Even if the touch has hung up, i can detect the Goodix GT911. I know that the address should probably be 0x5D but I thought it isn’t necessary to care about this problem as long as it works. After a reboot, the touchscreen works fine again until i use the lightmode of my GUI. Interesting to mention is, that i can click a thousand times for around 0,25seconds and no problems occur. But if I touch the screen permanently for around 1,5seconds, I instantly get my above described problems. Generally considered, this problems seems very strange to me and it doesn’t behave like any physical law i know…
On the first view, the error seems like a software issue ? Hear this!
If i use the official «Compute Module 4 IO-Board » to mount my Compute Module and Touchscreen, I don’t get the issue at all… My actual designed PCB ist the 2nd version. On the 1st version It also worked fine without any problems. The only differnce between version 1 and 2 is the wiring, which I tried to improve on the 2nd version and viewer parts which I only put on my 1st version to evaluate some functionalities like ethernet or 2nd I2C-Bus, which I’m not using on my 2nd version. The wiring did not change between these two versions, i only tried to increase the distance between the GPIO-traces to improve signal integrity.
So it seems like a hardware problem? But why does the GUI work fine in darkmode? I don’t have any explanation to that.
What did I do to narrow down the error?
I flashed a new image on my Compute Module and also used another Compute Module, Custom PCB and touchscreen as well, but without any success. As far as I experienced, the issue is only caused on my GUI and not on any other websites or images, etc. An interesting thing was the interrupt line, which is typically only drawn to 0Volts if the touchscreen gets touched. After the touchscreen hung up, I measured 0,084V on that line and as long as I touched the screen, this voltage rised to about 0,2V, which for me seems also like a strange behaviour. I also checked the «dmseg» file and got some entries for failed i2c tests of the GoodixGT911. I also tried the github fix for the swapped i2c address, but without success. I used the command «git clone GitHub - pimoroni/hyperpixel4: Driver for the Pimoroni HyperPixel 4.0" Touchscreen Display -b pi4-i2c-fix » for that.
What do I try next?
I dont have any clue what to do next. My only solution in mind, is to undo the «improved» wiring of my 2nd PCB to get as close as possible my first PCB version.
Conclusion :
I really need help and hope, someone can do me this favour. I’ve never found my described error behaviour in any forum. Are there any other usable forums for problems with the Hyperpixel 4.0? Let me please know.
Update:
I tried to reproduce the errors and specify the error source. As above mentioned, the touchdriver hangs up on lightmode (nearly every pixel on rgb(255,255,255)). If i change the color in lightmode to around rgb(245,245,245) the error does not occur. I also noticed that there are two flatband cables on the Hyperpixel 4.0: One for displaying the image and another for the whole I2C-Communication to the touch driver. I plugged out the one for displaying the image and got no problems at all. Even if was theoretically in lightmode(if display would have been on). The touchscreen worked fine and transmitted everyting flawless:
Conclusion on my Update: It seems as the rgb(666) datalines for displaying the image on the screen cause some problems on the I2C bus. I also checked the bus and the power supply with an oscilloscope but I haven't seen any unusual behaviour in any case. Voltage ripple was around 200mV Peak to Peak and the I2C-Datalines rised and fell really sharp
I still need help from you!
Thanks, Manuel

Pyscipopt (in Google Collab) does not show/print any output for the large-size network optimization problem in Google Collab

I am working on a non-linear network-optimization problem. When I run a large problem instance on the lab high-performance computers (imposing the time limit of 1 or 2 hours), those computers give me the output when the time is exhausted.
I wanted to use Google Collab to run the same code and to share it with my supervisors (they don't have Pyscipopt installed on their computers). However, when the problem size is small – all is good, but when the problem size is large, it says that the execution is completed (on the bottom of the screen) along with the time it took and a small red exclamation mark BUT it does not show any output for the large-size network optimization problems (neither it prints the solution nor it explains what is the reason/error of this behaviour).
Again, the same code works perfectly fine on high-performance computers, so I do not think there are any problems with syntax.
Please let me know if there are any solutions to the problem described.
Kind regards,
Lidiia
I tried to change "None" in the hardware accelerator to GPU and CPU. I tried to proofread the code in order to find any mistakes. I tried to not leave the Google Collab to run the code at night (I read somewhere that kernel stops working if there is inactivity) so I tried to click on something there to prevent the execution from stopping. Nothing worked.

Twincat 3: Modbus error 4 "ads mailbox full" turns on immediately in previously working project

I recently had a frustrating problem:
Modbus-connection throws in bError 4 as soon as bExecute is turned on. No variables could be read, and error persisted until reboot.
Previously working project stopped working over the weekend.
I might have fiddled around inside PLC, uninstalling couple libraries mainly, but logically thinking nothing should be wrong and I didnt do much at all. Its still possible I done goofed on friday, and didnt notice until after weekend.
On to the troubleshooting:
Reboot both machines
State machine is fine. Even made stripped-down project with one input and output and previously working minimalist state machine.
Reinstalled Modbus library in PC and PLC
Git revert the code couple weeks to a time when I 100% knew it worked.
PLC can ping PC in 1ms
Had an old project zipped in store, including "original" libraries
Reboot again
I still could wipe out PLC OS and start anew, but lets save that off for now.
"Thats all a mere mortal can do." I thought, and shot off a mail to Beckhoff.
Lets shoot off a mail to Beckhoff support.
Troubleshooting ensues:
Strip down the program even further, so only FB_MBReadInputs stays and bExecute can be flipped on or off manually.
Running only MBReadInputs, only MBWriteCoils, both at the same time
bError 4 problem persists no matter how much is stripped or ran.
Running the same project Locally on PC works just fine. Inputs can be read and output bits can be written.
In the end, flashing new image ended up being the solution.
Still in process of fiddling that out, so the actual problem isnt yet solved.
Update: Stuff works as it should. Some cosmic ray must have hit SD-card just right so during the weekend things got awry and problems surfaced.
Beckhoff image repo in my case: https://download.beckhoff.com/download/software/embPC-Control/CX90xx/CX9020/CE/TC3
Thats it, in the end wiping out SD-card is pretty basic thing to do when facing larger problems, but I just wanted to go through all the troubleshooting steps and end results for anyone struggling with Modbus and Twincat as much as I have.
I just reached out the same problem on CX8180. In my case there was some program uploaded before mine. I've activate my configuration and run PLC - get bError 4. TwinCAT errors code list says that is something with ADS mailbox and too much ADS calls. My program works fine on the same hardware elsewhere. Restart origin and activate configuration doesn't work.
I need to login with CeRHost and make a reboot of PLC. After that move communication works like a charm. The problem was the previous modbus communication.

Default Windows Dialog Browsing does not show "My Computer" nor "Drives"

Don't know if it's related to Eclipse, but it happened in Eclipse, so my first assunption will be, that it's something that has to do with Eclipse.
The problem is, for some strange reason, all of a sudden, whenever I can "browse" within Eclipse for a file/project, or whatever it is, the default window that is being shown does not contain any drives on my computer, and only a Desktop plus my user's windows folder. It is shown below:
As you clearly see, there is no way to go to the "My Computer" or any drive. I have a workaround (for now), but it will become pretty irritating fast, so I'm looking for a solution that caused all this. The workaround anyway, is typing the "C:\" or any drive letter, and hitting Browse button afterwards. If I do this, all is back to normal:
Anybody can help out a fellow programmer, who had the same weird case?
Thank God, the internet. After searching for almost 2 hours for this, I got lucky and found this thread:
http://forums.cnet.com/7723-19411_102-412058/browse-for-folder-missing-computer-and-libraries/
Well, when you have 16GB of RAM, 2 monitors, and 2 SSD drives (for some of you it might not be much, but for me it is), you kinda tend to loose yourself into thinking how "powerful" your machine is ;).
The answer was just like for the user in the above thread. I did have a lot of items on my desktop, that increased today. Seems at one point today I "crossed" the magical line, which broke the "Browse Dialog".
In anyway, posting here, if someone else will run into this issue in the future. I hope it will be helpful to someone.

OS Booting Issue

Because my work will get lighter for the next month or so, I decided to mess around with OS's, just to see how they work. I found this website, and I'm trying to run the code he provided. I am following the instructions exactly (to the best of my ability), but when I go to try booting with QEMU, I get this text:
SeaBios (version-blahblah)
Booting from Hard Disk...
Boot failed: could not read the boot disk.
Booting from Floppy...
And it never actually boots. I am relatively new to Ubuntu, and hoping that somebody would be able to point me towards where I made a mistake. I hope this is enough information to diagnose my error, and thanks in advance!
EDIT: Alright, I tried another tutorial which took me through very similar steps (but with slightly different code), and I still had the same issue. I also booted MikeOS from the floppy image it comes with, and it worked fine.
EDIT 2: Aaaaah! I just realized that when I pressed Ctrl+C, the text that was supposed to appear appeared for just a moment, then went away, along with QEMU. What can I do to make the text appear sooner? I've tried moving the infinite loop to after the display command, but to no avail.
I want to start by saying that I didn't read the entire page you provided (as I don't have enough time). However, the error that you cannot boot from HDD, regardless of the OS, usually (always in my previous experiences) means that either the MBA (Master Boot Record) is messed up/incorrect or you don't have a partition with a boot flag on it.
When I have some time I'll look deeper into that page and see if i can find exactly what the problem could be.
Do you have the bytes 0x55, 0xAA at offset 510 of your MBR?