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Having problems with the touch screen on my sensation and this has now happened on my secound phone! both phones were ok out of box but after a few days first noticed problems from lockscreen as phone would not always unlock when draging app icon into circle then slowly geting worse until would take several swips on screen to even unlock! then started noticing similar problems in norm opperation? sometimes works ok but some times freezes up have tried factory reset and no differance. very strange having this problem on two phones?
Does the touch screen stop working completely?
Mine did that on Monday, had to get a replacement.
it seams to stutter once awake works slightly better? but still not responsive
I've noticed that the proximity sensor and gyroscope are being used aggressively to filter accidental screen presses.
For example, if I place my sensation flat on a table, the lock screen is very hard to unlock. If i place my other hand near the proximity sensor at the same time (or tilt the phone towards me) it unlocks easily. Until I identified this functionality I was beginning to think my right index finger was unsuitable for touch screens (since when placed on a table I tend to use my right hand, but otherwise use my left to unlock).
Hopefully this will be tweaked with future updates.
Sent from my HTC Sensation Z710e using XDA App
Many thanks I hope itd that simple?
I am having the exact same problem, for example on the lock screen I would swipe up but the ring will move slightly, and one icon I.e the camera icon will move towards the ring, another grip which is buggin me is that it will miss screen taps, I.e when texting or clicking an icon one tap will go unnoticed by the device resulting in either a missed letter, or the app not opening. This also goes for the 4 command buttons at the bottom, it happens on these too. I also get the occasional lock up.
Factory reset did not work
All of you are you using Sense, and no other launcher?
i900frenchaddict said:
All of you are you using Sense, and no other launcher?
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Click to collapse
Had the exact same issue on my first phone but i was using adw launcher, not installed it on my second phone and had no issues at all
Sent from my HTC Sensation Z710e using XDA Premium App
I am currently using launcher pro, but even using the htc stock launcher the problem still arises. When I did a factory reset, the problem was still apparent when entering my pin number for the first time.
Kurisu87 said:
I am having the exact same problem, for example on the lock screen I would swipe up but the ring will move slightly, and one icon I.e the camera icon will move towards the ring, another grip which is buggin me is that it will miss screen taps, I.e when texting or clicking an icon one tap will go unnoticed by the device resulting in either a missed letter, or the app not opening. This also goes for the 4 command buttons at the bottom, it happens on these too. I also get the occasional lock up.
Factory reset did not work
Click to expand...
Click to collapse
As I stated before, I experience this problem but it only occurs when the phone is laid flat and my hands are well away from the proximity sensor at the top left of the screen. I can say that the part you are describing with the lock screen is 100% the same problem I come across in certain situations.
Please test to see if the problem is still present when the phone is tilted in your hand and, if you are laying the phone flat when you experience the problem, try putting your other hand near the proximity sensor when you try to unlock.
If this happens as I describe then it is most likely a software bug which only affects users who have particular phone use habits.
Saying that, as you are having quite severe symptoms, during general use, it may be that you have a faulty proximity sensor in your phone - leading to missed screen taps when the phone thinks you are not touching the phone.
Well I laid the phone flat and unlocked it no less than 20 times, each worked flawlessly no problems at all..... Seems to have me baffled
Yes I've been having the same problem. First noticed it when trying to unlock it (phone was lying down), couldn't get the circle to move. Have had one complete touch-freeze. No input possible, however volume and power button worked. Took the battery out, restarted, and it worked fine.
I notice that input can be difficult sometimes, hit and miss or just have to push harder. Strange. Seems like a software issue to me.
edit: just had the same issue - circle wouldn't move. After picking the phone up I was able to unlock it, however still not as easy as it should be, a bit jerky.
Both my evo and my g2 had a grounding issue, for example if I had the phone laying down on the couch or bed, the screen would not respond to touch but if touch the phone with a finger and try to unlock it with my other hand it would work normally. So it seems to be a common problem with some HTC devices
Sent from my LG-P999 using XDA App
aim1126 said:
Both my evo and my g2 had a grounding issue, for example if I had the phone laying down on the couch or bed, the screen would not respond to touch but if touch the phone with a finger and try to unlock it with my other hand it would work normally. So it seems to be a common problem with some HTC devices
Sent from my LG-P999 using XDA App
Click to expand...
Click to collapse
The wildfire (my friend's got one) has this problem too. You have to keep touching the metallic housing for it to detect any taps.
You are correct, aim1126. I never considered grounding to be the cause but after re-testing it clearly is.
I guess it is a side effect of having a conductive unibody. So basically there will be no software fix, we just have to keep constant contact between our hands and the unibody. I wonder whether a rubber bumper would actually make this problem worse?
Edit:
Actually, the screen seems to adapt to not being grounded properly after a couple of presses. It works fine for me by the third time I touch the screen - weird. Well at least it is only a minor annoyance!
Sent from my HTC Sensation Z710e using XDA App
aim1126 said:
Both my evo and my g2 had a grounding issue, for example if I had the phone laying down on the couch or bed, the screen would not respond to touch but if touch the phone with a finger and try to unlock it with my other hand it would work normally. So it seems to be a common problem with some HTC devices
Sent from my LG-P999 using XDA App
Click to expand...
Click to collapse
My wife uses a G2 and I wouldnt call it a grounding "issue" honestly seems like more of a feature to make sure you ment to engage the screen.. Its kinda cool IMO
As far as the screen being laggy this sucks since I wanted to upgrade from my Vibrant to the Sensation.. I also am not sure its a software issue you guys are having.. I am running Sense 3.0 with gingerbread on the G2 and it is very smooth.. The option to silence a call or tirning on speaker phone by turning the phone over is neeto torpedo..
I'm having the same issue, from lock screen I drag the circle up and it just stutters. After a few tries it usually works, once unlocked the touch screen appears to work fine. I'd expect the issue would continue after unlock if it was a hardware issue.
mr_wi said:
I'm having the same issue, from lock screen I drag the circle up and it just stutters. After a few tries it usually works, once unlocked the touch screen appears to work fine. I'd expect the issue would continue after unlock if it was a hardware issue.
Click to expand...
Click to collapse
I made a video about the issue here, where you can see that the touchscreen problems do indeed persist after unlocking. Especially when typing and scrolling.
http://www.youtube.com/watch?v=Bk1BlXZQDrU
bcpk said:
I made a video about the issue here, where you can see that the touchscreen problems do indeed persist after unlocking. Especially when typing and scrolling.
http://www.youtube.com/watch?v=Bk1BlXZQDrU
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Click to collapse
That's very bad. Flaky lock screen is not good, and the example of not being able to scroll through apps without it running one is a killer. There are many times when scrolling through a list of selectable items is necessary.
Are you going to exchange the phone?
Have my hopes set on the Sensation, so would really like to find out what the resolution is.
happens in the pocketnow review that brandon just put up
http://www.youtube.com/watch?v=nlSvcOkoEwk&hd=1&feature=player_detailpage#t=143s
Issues with touchscreen being unresponsive.
Important Isuue usually appears at least after a week of owning the device
Quick test:
Lock device. Unlock, launch camera app in the lockscreen, take picture, try pressing back button, see if it responds straight away or with a delay. Test it with all apps on lockscreen.
Issue unlocking ? I.e dragging circle to the middle?
Bottom of a screen not responsive sometimes.
Back button slow to respond.
Apps launching when you try to change screen, i.e. phone registers swipe as a press.
http://www.androidpolice.com/2011/06/06/is-your-htc-sensation-having-touchscreen-problems/
CAUSE Grounding pin not touching back cover, which causes (by the looks of it) build up of static which messes up touch screen.
FIX Best to use in conjunction with fixes below.
POSSIBLE FIXes if above doesn't work, which it should, but don't expect immidiate results.
1.Shut down phone and pull battery out for at least an hour (i recommend overnight). Press power button as to turn phone on, which in theory should discharge all the left over current in the hardware.
Give it a go and let me know if it works.
2.Letting battery discharge till phone turns off,put on charge and don't touch it till it's full.
I want to thank abrown0809, eliteone, stuart0001(legendary patience ), zmfl, maschenazi, nugzo and all other people i forgot to mention for sticking with me while trying to work out FIX. Thanks to all the posters too.
I take NO credit for the fix.
Poll is here to show how many people have this problem to HTC, not to work out what percentage of users have it, as it will definitely be incorrect.
Vote yes if you EVER experienced touchscreen problems, even if its gone now.
PETITION for HTC to admit that there is touch screen problem.
All info below:
stuart0001 said:
Below is the worldwide support address. There are also country specific contact pages but I'd suggest we all contact the same place so they can't keep saying they're getting no reports.:
http://www.htc.com/www/contact/email-us/
Might be worth at least including the link below which demonstrates our issue perfectly
http://www.androidpolice.com/2011/06/06/is-your-htc-sensation-having-touchscreen-problems/
Click to expand...
Click to collapse
stuart0001 said:
I've also started a pertition here:
http://www.ipetitions.com/petition/htcsensationtouchscreenproblem/
Feel free to comment, sign & distribute as you wish
Click to expand...
Click to collapse
HT157V No issues
HT15HV80XXXX 6/1/2011
HT15BV80XXXX 6/8/2011
HT15EVXXXXX 6/13/2011 Current Device
Had big problems with the first two, both returned... Third is an improvement, however:
Seems to be a problem with the application data screen (where you can move to SD etc...) all of the data goes mental and the buttons flash sometimes causes a crash that only battery removal cures...
Back button seems to forget to work when the screen unlocks, normally returns to normal after several actions
Unlock screen is hard to unlock sometimes... helps if you are holding the device...
Screen is sometimes slow to respond
SD app icons on home screens do not regenerate after reset...
HT15JV
Circle issue in Lockscreen, and fast wish in appdrawer starts any app.
here's a video from me:
http://www.youtube.com/watch?v=zgpjmQyqYXA
@OP, what is the touchscreen issue btw? I haven't read anything about it...yet.
HT15TT - 05/26/11
No problems yet!
ht15tt
no problems
HT15CV
have the Circle issue in Lockscreen, Battery drains almost 50% in 1h wlan surfing, apps crash sometimes and at least restarts...
bet that ^^
im returning it next week i hope they will change it
HT15GV - No problems, touchsreen working perfectly.
Humming Bird said:
@OP, what is the touchscreen issue btw? I haven't read anything about it...yet.
HT15TT - 05/26/11
No problems yet!
Click to expand...
Click to collapse
Edited first post
HT15JV - no touchscreen or lockscreen issues so far
Only real bug is that non HTC widgets sometimes get flickering rainbow coloured stripes but they are strictly attached to the widget and vanish once I replace the it. So this should not be a display problem especially as the HTC widgets are never afflicted.
HT15ZT posting video now
My HT161T no issues at all
Sent from my HTC Sensation 4G using XDA App
HT15HV, no issues yet.
Had the issues on my first device, but don't know what serial it had.
Sent from my HTC Sensation Z710e using XDA Premium App
HT15MT
It had lockscreen issues yesterday. But it went away.
Sent from my HTC Sensation 4G using XDA Premium App
HT15ZT and haven't noticed any issues.
HT15RT, may build and ship date
all of the above in terms of problems. unlocking problem, bottom of the touchscreen not being responsive, swipes registered as taps fairly frequently, issues with wifi cycling and never connecting, and it has ruined the SD card it came with (do the point that it gets detected by my win7 computer but crashes explorer, and on my mac it just isn't detected) as well as the 16GB microsd I foolishly swapped in from my DSLR.
Did I mention that I still am absolutely in love with the phone?
Hmmm, still a bit random.... We just need to find a common factor. If anyone spots anything in common, just mention it, even if you are not sure.
I appreciate this thread. I am still considering purchasing this phone but the two major hold backs are the wifi signal deathgrip issue and of course the touch screen. I kinda went through this debacle with the mt4g and don't really want to go through the hassle again of finding a working model.
Sent from my HTC Glacier using XDA App
Did those with or without problems use a screen protector?
I left the stock screen protector on my unit and it works beautifully. Maybe because the touch screen unit is slightly displaced, static build up on the gorilla glass causes issues with some unit?
HT15RT works perfectly
Don't know if its my lockscreen only but whenever I have the weather lockscreen and its in the triple digits (eg. 100 degrees and over) right after you the weather animation the temp won't display properly. If its 100 or over the 1 will be to close to the right edge and you won't be able to see it. Anyone else getting this.
asj2583 said:
Don't know if its my lockscreen only but whenever I have the weather lockscreen and its in the triple digits (eg. 100 degrees and over) right after you the weather animation the temp won't display properly. If its 100 or over the 1 will be to close to the right edge and you won't be able to see it. Anyone else getting this.
Click to expand...
Click to collapse
yeah i also noticed this too and it annoyed me so much, i was like wtf is 02 degrees, instead of 102...but yeah i hope this gets fixed somehow
just tried it on mine. Yep, same issue. very odd. I've also noticed that on the clock when it's over 100 & clouds are there the 1 is covered up
Mine is fine
nextonline said:
Mine is fine
Click to expand...
Click to collapse
are you in an area with 100+ weather? if not, of course yours is fine. this thread is stating that once it hits 100 it gets wonky
Man this six on htc part on how this could be overlooked, really hope this gets fixed soon. It no biggie but its just anoying that's it there.
Using the weather lock screen. Today I got the bug where the bottom half of the screen was black and the whole lock screen was shifted up. I think someone else posted about this in another thread, but after trying to switch between lock screens it looks like it's specific to the weather lock screen.
If it helps, it seemed to happen after I disconnected the phone from my car charger. When unplugging it, the screen was all screwed up. I just hit the power button and got out. Later when unlocking the phone it looked like the phone was trying to put the lock screen in landscape, but just freaked out and it never lined up again.
Reboot fixed the issue.
DeezNotes said:
Using the weather lock screen. Today I got the bug where the bottom half of the screen was black and the whole lock screen was shifted up.
Click to expand...
Click to collapse
I experienced this yesterday.
Axefield said:
I experienced this yesterday.
Click to expand...
Click to collapse
Yup. That's it.
Sent from my HTC Sensation 4G using XDA App
now that i been using the sensation for a few days now i notice overall sense is really buggy, not just with the lock screen. i had times where the screen wont respond to my touch, launcher force closing and even random reboots. i really hope htc ota a update soon to fix all these issues.
get your lock screen back
Battery pull will reset your lock screen to default, I did it with the phone on and screen in portrait mode, but it won't stop it from doing it again.
I discovered that should you activate pattern lock, the camera will show no functionalities such as taking picture or anything. It will gave you the viewfinder and nothing else.
This happens when you bring the camera icon into the ring while in locked screen.
suhaimidee said:
I discovered that should you activate pattern lock, the camera will show no functionalities such as taking picture or anything. It will gave you the viewfinder and nothing else.
This happens when you bring the camera icon into the ring while in locked screen.
Click to expand...
Click to collapse
I had this Bug.. but it's fixed in the OTA update..
Haha, hooray for celcius.
I think this is a feature, not a bug. It's a mind trick. This helps you to think it is cooler than what it really is.
Sent from my HTC Sensation 4G using XDA App
asj2583 said:
how this could be overlooked.
Click to expand...
Click to collapse
Easy, the rest of the civilized world doesn't give a **** about the a temperature scale that's horribly broken and mostly made up. Why the US clings to archaic scales of measurement is baffling.
Matt1408 said:
Haha, hooray for celcius.
Click to expand...
Click to collapse
+100000000
Sent from my HTC Sensation Z710e
I have just replaced my digitizer (was dust under the screen and also a scratch on the digitizer itself, along with the fact I damaged it removing the sticky tape) and the whole screen is almost completely unresponsive. Brand new, but wont work fully until I touch the screen for a bit or give it time to sit after activating the lockscreen.
Once it is through it's "warmup" the screen works flawlessly. It just acts like a slug before that... Also rendering the quick launch lock screen completely worthless. Anyone have any ideas what could be the culprit?
Sent from my HTC Sensation 4G using XDA Premium App
I too replaced a broken screen on my sensation, and i am experiencing the exact same problem as you. Only for me it's only the lower left part of the screen that 'takes time to warm up'.
Did you find any solution?
Not yet. I have another digitizer on order, and fingers are crossed. If not, ill be biting the bullet and waiting for the nexus prime. I have this feeling that it is something other than the digitizer which is extremely sensitive. If people are claiming responsiveness issues after a week or two of use, and while on their sixth or seventh sensation... It sounds like something is slowly deteriorating or building up.
Sent from my HTC Sensation 4G using xda premium
I don't think it's the digitizer either, probably something else ont he phone. However i don't think it is the same problem as everybody else is having, since they experience their screen being unresponsive in general rather than just after turning on.
I am though going to try some of the fixes suggested, i.e. improve the grounding by placing some aluminum foil under the cover and see if it helps.
What does "turning on" mean? Cold boot up? If so, then the CPU on the phone will be busy doing stuff. If you mean waking up from sleep, then that's another problem.
for me it's both cases, both when booting the phone and just when turning the screen back on. What's strange is that it is only the lower part of the screen that's frozen :-S after 10-20 seconds it suddenly springs back to life just as nothing had happened and works flawlessly until i turn the screen of. Then i see the exact same problem again.
I also noticed now that the screen also freezes after calling somebody and when you hang up :-0 I really don't know what is wrong with the phone!
If the phone is unsecured (never sleeps) it will work flawlessly. As soon as I click the top button to secure the screen, or take a phone call, once I try to unlock/ use the screen again... The problem comes back. The left side of the screen is the most responsive, usually moving my finger around for about five or ten seconds will restore full sensitvity. I received a new digitizer in the mail, just waiting on tape. Interesting note; they are different digitizers. The original was HTC/ tmobile brand while the replacement is simply HTC. The ribbon cable also reads different. My original: pyd v1.0, sw-10 94v-0, e3082521117. The new one reads: pyd v1.0, e21954-1, ruICACichia, 94v-0 1112. The current digitizer replacement is also a standard HTC label... I wonder if it is because it isn't a specific model replacement.
Sent from my HTC Sensation 4G using xda premium
Alright so i tried doing all the fixes related to the grounding issue, and i didn't affect anything at all.
I'm going back to the repair shop today (have a three months warranty) to tell them to have a look at it again and see if they can fix the issue. Maybe they have a spare digitizer they could try instead of my current one. I will let you know if anything helps!
Sounds good. I am betting its either an incorrect digitizer for the model of phone (us/eu/whatever) improper mounting or damage, or just planetary alignment or something equally stupid. I'm really hoping someone figures out this problem... It is frustrating to spend more time figuring out how to fix a phone than you actually do using it.
Sent from my HTC Sensation 4G using xda premium
what9000 said:
Sounds good. I am betting its either an incorrect digitizer for the model of phone (us/eu/whatever) improper mounting or damage, or just planetary alignment or something equally stupid. I'm really hoping someone figures out this problem... It is frustrating to spend more time figuring out how to fix a phone than you actually do using it.
Click to expand...
Click to collapse
True, had i known from the start i would probably just have bought a new phone, rather than spend on the money on getting the screen replaced :-S
Well, I replaced the digitizer for a second time. Seems to be the same thing so far. Different initial responsiveness spot (looks like the right side might be more sensitive now) but I didn't have high hopes. I wonder what it could be...
Sent from my HTC Sensation 4G using xda premium
So i went back to the repair shop and got it fixed. I guess they weren't in the mood for scientific inquiry, because they simply disassembled the phone and installed a new digitizer. After that everything is working fine, altough i will never know if it was the digitizer itself or some faulty wiring somewhere :-S
Worked for me
I have had exactly the same problem you all have experienced. The first digitizer I ordered from a company on e-bay gave me huge problems at the unlock screen. Bought a new one from skalshop and it works perfectly. I even tried it without tape to make sure it worked before I glued the thing together and it worked perfect.
Anyone have their screen blink/flick on startup, on when you see sense rings for unlock. This doesnt happened all the time but you will notice it once awhile.
Is this hardware issue or software? Its not custome Rom I'm running. I tested out other and it sometime occur. On HTC One X it mention about this also.
Any input would be helpful. I don't like to flash Rom all over too see what caused it.
Sent from my HTC VLE_U using Tapatalk 2
I had an issue with Apex launcher. Every time I would select a folder on the home screen, the screen would pixilate, tile and flicker, not in that particular order. I uninstalled Apex and now everything is fine.
I read that the type of screen used on the One S has a type of matrix pixel or something that can be seen by a trained eye. Could that be what you are seeing.
hTc One S
I've been testing with this flickering. It noticeable if I restart my phone and look at the screen before the "sense ring" pop up. The screen will flick once. This occur on stock, custome Rom so I might think the hardware is acting up. This issued is known on HTC One X.
I restore back to stock Rom and move between app it also flick. Messed with brightness seen to help, but once I select auto brightness it come right back.
Man I'm not happy
Sent from my HTC VLE_U using Tapatalk 2
Talked to Htc rep. they might consider the display went bad. Usually, the screen shouldn't blink. Even when I reopen an app..it still flicker and turn black screen.
Next steps called back Tmobile and demand a exchange because I'm not happy with my $600 phones..that blink like strobe lights
Maybe I should never buy the first patch that released on launch day. LOL
Sooo... mine started doing something weird this morning...
Is it anything like yours is doing?
https://www.youtube.com/watch?v=PrW9xwdGd38
Aydthird said:
Sooo... mine started doing something weird this morning...
Is it anything like yours is doing?
https://www.youtube.com/watch?v=PrW9xwdGd38
Click to expand...
Click to collapse
That is worst then mine. My just blink sometime.
You should get a replacement. That is a bad backlights
Sent from my HTC VLE_U using Tapatalk 2
x1tyme said:
That is worst then mine. My just blink sometime.
You should get a replacement. That is a bad backlights
Sent from my HTC VLE_U using Tapatalk 2
Click to expand...
Click to collapse
Well it was weird, it was fine last night, even had done a backup on clockwork. took it off the charger this morning and restarted it. looked at it later and half the screen was like that. I restarted the phone again and it only did what you saw, tried restart couple times still came back but later on as I was finally leaving home I was texting someone and it just went away?? tried restarting it again nothing... not coming back?? no idea why. I did see on youtube another person with a one X doing the full screen like that, SCary.
I would return it but I'm rooted 2 months in and had to buy from someone else's upgrade so I'm not even sure what they'll tell me if I take it to the store or talk to HTC
I got replacement from T-Mobile since there 90 days exchange warranty and guess what? My screen still does it. I went ahead called HTC for advice and rep. Told me it just parts of O.S.
For yours side, if you sent to HTC for a repair. They might check if you tamper with phone and will charge extra :what:..
Hopefully it won't do it.
Sent from my HTC VLE_U using Tapatalk 2
only once in a while, when on lowest brightness, the screen would flash up very bright, after pressing the on button but than goes back to set low brightness.
Don't have an Issue like in your video
I've reverted the phone back to stock, not only does it still do it, but it was doing it while on the restoring mode. I've called T-Mobile, they are sending me a new phone. Unfortunately now I will be getting a refurbished phone. Pretty unnoying.... Hope its not defective too in some ways.
Sent from my HTC VLE_U using XDA
my screen will have a black square in the top left that will occasionally flicker only on the home screen when I swipe through. Does anyone have this specifically? Really hope there is a fix, it is quite an annoyance.
mattmann95 said:
my screen will have a black square in the top left that will occasionally flicker only on the home screen when I swipe through. Does anyone have this specifically? Really hope there is a fix, it is quite an annoyance.
Click to expand...
Click to collapse
Nope, that's all you.
On an other hand, my phone is only getting worst every morning I wake up.
Sent from my HTC VLE_U using XDA
Aydthird said:
Sooo... mine started doing something weird this morning...
Is it anything like yours is doing?
Click to expand...
Click to collapse
I have the same issue, but in a bigger area. I noticed that it happens when the screen is too cold.
First time it happened was when I was taking some pictures outdoors and it was under 0°C and snowing.
Second time also outdoors, strong cold wind, but above 0°C.
Don't know if this is really the cause, but it always happens under these conditions.
victinlauria said:
I have the same issue, but in a bigger area. I noticed that it happens when the screen is too cold.
First time it happened was when I was taking some pictures outdoors and it was under 0°C and snowing.
Second time also outdoors, strong cold wind, but above 0°C.
Don't know if this is really the cause, but it always happens under these conditions.
Click to expand...
Click to collapse
Mine originally started on a random morning, I live in Cali and phone usually on my bed so granted it's not under the blanket I'd imagine it stays fairly warm at nights. tho I had touched the screen with wet hands before and I've always been curious if that would have done it. I did since get a replacement which I haven't babied as much as the original one, it's been few months and seems to handle itself fine now (crossing fingers).
But if it happened once, it will happen again, mine came and went couple times, here is couple vids of the way it got... but eventually instead making a transparent gray, it was a full shade of it blocking that half of screen that wouldn't go away.
https://www.youtube.com/watch?v=cUM1FiLeb0c&list=UUvGuDLwvPLcA79xqQvL_OHA&index=7
https://www.youtube.com/watch?v=zM8rZc1_Pbk&list=UUvGuDLwvPLcA79xqQvL_OHA&index=1&feature=plcp
https://www.youtube.com/watch?v=21OaktvRsWU&list=UUvGuDLwvPLcA79xqQvL_OHA&index=6