Looking for an explanation as to why

Hi, I have a confusing problem, I have an iMac that is booting with the usb pen drive (linux mint) and running great, but goes to a black screen when I install and try to run it from the hard drive. Well, I have now figured out that if I connect the computer to a tv from the mini display port to an HDMI port the computer display works great, and at that point I can disconnect the cable between the computer and the tv and continue using the iMac. I am wondering if anybody has an idea as to why this works and how to make it boot up normally without the tv connected? Another interesting thing about it is, I can boot the computer up to the black screen and then connect the tv and the computer screen starts working again and at that point I can unplug the tv from the computer and use it.
Any thoughts on this would be appreciated.
Thanks, Rich

Hi Rich. I’m not familiar with Macs, but from what you’re saying, it sounds like you may not have a display driver installed on your Linux installation on the iMac, since Linux works when you connect the computer to a tv using a cable.

I’d suggest that when you have your iMac connected to the tv, you check your Linux system for additional drivers. You can probably find that in the Settings section of your Linux install or in its software store. Try typing drivers into the search area of your start menu, and it will likely lead you to where you can check for drivers. If you get the proper driver for your iMac, then I’d suspect that you could then reboot your system without using the tv cable and it would display on the iMac’s own screen. Just a guess but worth a try. Hope that helps.

having a similar issue with MBP, I had it running and after reboot I got acreen with message about

assertion `ELWF(R_TYPE) (reloc->r_info) == R_X86_64_RELATIVE’ failed!

first time at that screen, the reboot succeeded, next time through reboot cycle it came up that way on 3 consecutive restarts.

Hi @Blueghost05, I gave it a shot but the driver manager still says that all my drivers are good and there are no alternatives available, I do think it is a driver problem but don’t know how to find or install another driver without going through the driver manager

rlegarra, I’m thinking that it might possibly be something that be corrected in the Display settings. When you connect a laptop to a TV, you have the option of showing the output on both the laptop and on the TV. While you’re connected via HDMI to your TV, go into Display. It may show your TV setting and have an option for your monitor as well. See if you can make the computer monitor the default monitor, so it’s used when you boot up, so you don’t need to use your TV to see what you’re doing. That way, you may be able to set it up so you can use either the monitor or the TV as a display, but at your choice, not automatically, or at least both of them, not just the TV only.

MacksM3, I put this into my browser’s address bar to do a search for possible answers: what does this MacBook Pro error message mean: assertion `ELWF(R_TYPE) (reloc->r_info) == R_X86_64_RELATIVE’ failed!

I got a number of replies which I can’t evaluate since I’m unfamiliar with a MBP. So I suggest that you run that or a similar search query to see if any of the answers seem relevant to your situation.

Doing an error message online search is often, but not always, a way to resolve an issue.

Hi @Blueghost05, thanks for your input.
I did put that error into the search engine and a found reply that said to ignore it and reboot. That worked once. next time I say that error it came up on 3 consecutive reboots so I did a restore of the Mac OS and put the MBP conversion at back of list of things to do.
My daily driver is an old desktop machine with debian that works great. Old bios do not support virtualization so I want to use the MBP for that, but right now I don’t use that machine at all, so not critical that I figure it out right away.

OK. Glad you have a machine that’s working for you. Perhaps in the mean time you’ll come across just the info you need to get that MBP purring like a Linux kitten. Keep learning.

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@Blueghost05 I can go into display settings and see the monitor or the tv or both if the tv is connected, if it isn’t connected I can’t see the computer monitor after booting until I connect the tv again. I tried to make the tv the default and I then after a reboot couldn’t see the computer monitor, and couldn’t get into the system settings to make the computer the default again and had to reinstall LM again to get the computer monitor back to the default screen. This is a dilemma.

@rlegarra I would have thought that you’d want to make the pc monitor your default, rather than the tv, since you were having problems finding it. Since you made the tv the default, I suspect that prevented you from seeing the monitor at boot up. So if you reinstalled LM and got your monitor back, what’s the dilemma?

I thought I might be of help to you, but this is as far as I know. Perhaps Vasileios can assist you on this one.

Sorry @Blueghost05, I don’t mean to confuse you. I tried making my tv the default monitor and rebooted because I can only see the computer monitor with the tv connected. It probably wasn’t the smartest thing to try but I’ve run out of ideas. The reason this is a problem is I want to use this computer in my shop which has very limited space and I don’t have enough room to put a tv out there just so I can use the computer.

If you want the computer to be the default monitor, shouldn’t you be able to set that up while connected to the tv, so that when you reboot, the computer monitor would work?

I have the computer monitor set up as the default but for some reason the computer boots to the black screen and will only show when I connect the tv to the computer after the computer monitor shows up I can then disconnect the tv and everything is great until I need to reboot. I’m pretty new to this stuff but this seem pretty weird to me

@rlegarra I noticed it has been a few days since you posted. If your issue is not fixed let’s ask
@vasileios if he has any ideas any ideas on a fix for this situation. Cheers!

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@BigDaveAZ, thanks for the response, actually @vasileios came to my rescue and the problem has been solved. Short answer, he had me add “nomodeset” to the grub comand line and it solved the problem.I am now booting the computer to a live monitor without hooking up a television.
Yesterday was a good day.