Here is a page I found to doing a hard reset and resetting your password with your google account. It looks like you won’t need to do a hard reset, but keep in mind that you need to back up your data if you do because it will be deleted permanently from your phone upon doing so. https://www.hardresetandroid.com/blu/blu-dash-jr-3g-password-reset/
I’m not a professional tech, but it sounds like screen is damaged internally. If you want to fix it yourself, look here for the tools and price of a replacement: OnePlus 6 Repair Here is the link to the screen on the IFixIt Store, and to another seller online: OnePlus 6 Screen https://www.mobiledefenders.com/lcd-digitizer-frame-assembly-for-oneplus-6-black.html Here is a guide I found online also: https://www.youtube.com/watch?v=9CzGF_DF... Otherwise, you should probably take it to a shop. Not sure on the price there but I bet it will be a good bit more expensive than doing it through IFixIt. And if you want a good kit with all of the tools you need for this and future repairs except for a heat gun, check this kit out here: Pro Tech Toolkit
I found this online thread where somebody got the same error code on their MacBook Pro. It pointed to a battery issue and some rouge app. Not sure it it’s what is happening here, but it might be helpful nonetheless. https://forums.macrumors.com/threads/app...-hardware-test-result-code-meaning-4sns-1-40000000-vd0r-18-616.2131512/
I would need more information to make a good diagnosis, but I would start by checking the fuse box and the bulbs. It might also be worth checking the wiring if none of that works to make sure there is no short circuit with the frame or something.
Please disregard everything that I stated below, but I am keeping it for people to see. I was incorrect, and I did not do my research. I’m just a hobbyist trying to break into the community, and sometimes I’m wrong. I apologise for the misinformation, and I hope to learn more so that things like this do not happen again. Hello, I looked on Apple's website, and according to it they did not release a 21.5 inch IMac in 2015. To get your model number, click on the apple in the upper right corner, and at the top of that menu, click 'About This Mac'. On the first page, it should say the type and model of your computer. Just edit the question or post it in the comments and I can get an answer for you.