Thanks for your reply mate. I've gone right in now and taken the screen assembly out. It looks like the ribbon cable to the display has gone weak. So I've ordered a service pack screen and frame. I'm confident this will sort it.

Hi guys.

Have any of you come across the S21 Ultra display going off without any reason? ie No water damage, no impact, it simply went black while i was watching a video online. There was sound when the screen went off momentarily but once i tried rebooting the phone nothing.
The whole screen is black when i force a restart & it does vibrate to say it is booting up but when it went off, i had it in silent mode so cannot hear if it does actually boot up. Ive tried connecting it to my pc but again, nothing., This is more than likely due to me previously connecting via Samsung Flow.
I love this phone & have removed the rear cover & disconnect the battery via the connector inside but again, this has done nothing.

I have a hunch the whole display may need replacing but it's quite an expensive gamble if maybe the problem is mainboard graphics related.

Any help would be greatly appreciated.

Gazza

Sorry it’s taken so long to reply, Have you checked the micro switch is working on the memory card door? If it is stuck in the open position then the camera won’t power on. You can usually tell if it works by pressing it in with the end of a pen or something. You should hear a noticeable click. If you don’t hear it then they are fragile & do sometimes stick.

Hope this helps.

See my reply below. There isn’t one.

Gazza

I can vouch that there is NO CMOS battery on this laptop. I now own one from a friend who had it condemned by another ‘repair tech’. It turned out that the display connector was not secured properly. Anyway, having stripped it down completely, i decided to replace the CMOS battery before putting it back together & there isn’t one. On the underside of the board is an area with white plastic in the shape of a button battery. On reassembly i noticed the CMOS had lost the clock memory. Which i put down to disconnecting the battery. It must be powered when the battery is connected & not separately.

Gazza

I used your guide when i repaired my mates X553. I found it quite easy. So thanks for the heads up on what to look out for :-)

The battery i removed yesterday had way more adhesive on the under side than in the above pic. I ended up having to get the old battery fairly warm before the adhesive would release. A tip if you are doing this is to use an old credit card cut in to narrow strips and insert them in to the gap where the adhesive release. That way the battery shouldn’t re-stick before you remove it.

The NFC Antenna is delicate. If you are just replacing the batter then i had to use a bit of heat to soften the adhesive before gently peeling it away from the battery. The adhesive is quite stubborn.

If you do not have any picks, You can also adapt an old credit or utility card by cutting it in to thirds. Then with some fine emery or sand paper, rub a sharp point on the one edge of the card. This will help you get access to the clips that hold the rear cover on. The one i did yesterday had quite a lot of adhesive around the edge & around the finger print sensor. Another tip with an old credit card is to cut it in to narrow strips to insert in to where you have separated the cover from the frame to stop it getting stuck to the adhesive again.

Another alternative if you do not have the iopener is to use a bed time hotwater bottle. Do not over fill it though. Just put enough hot water in to support the phone while you work around the adhesive.

I use both the hot water bottle and iopener together on Samsung's. It makes life easier