It all began with the mysterious appearance of these vertical lines on my screen.
After doing some research, I learned that there are two causes for this phenomena: 1) loose internal LCD connections or 2) bad LCD assembly.
I decided to find out which one was the cause for the lines on my Redmi 13C.
After using a heat gun along the outline of the phone back casing, I carefully pried a small opening on the side seam and worked some credit card wedges into it until the whole bead of glue was separated.
Then I removed the SIM/MicroSD tray and all the screws.
It's easy to lose small parts, so I made sure I put the group of screws in a safe area of my working surface where nothing could make them scatter onto the floor.
After removing the battery, I detached and reattached the two LCD-phone connections.
I reassembled the phone and turned it on.
This is what I got.
The vertical lines were now semi-transparent and had multiplied throughout the whole screen.
That's when I knew that my problem wasn't just loose LCD connections, but a faulty LCD assembly instead.
(Heavy Sigh)
I shopped online for a new LCD replacment for my Redmi 13C and found one on Shopee for 604 Php ($10.33) - price includes shipping.
"Not bad for a new LCD assembly", I thought, "Now let's see if it is genuine - not a knock-off and if I can do the replacement procedure without breaking anything else!"
The order arrived about 5 days later and included a nifty tool kit too.
Just as before, I removed the back, the battery and the screws. I detached the LCD connections, heated up the front and separated the old LCD screen from the phone.
Then I installed the new LCD screen assembly and reassembled the phone.
When I turned the phone on, I was happier than a pig in $hit!
The screen was perfect and the touch response was "better than new"!
(Doing the "Happy!, Happy!, Joy!, Joy! Dance" now...)
Submitted FYI.
May you and yours be well and loving life today.
In Lak'ech,
JaiChai