Lg tv Horizontal black stripes after replacement work

Hi everyone,

I have a LG 49LF550T

The TV was recently repaired for Backlight and power board replacement.

After getting it back, I noticed one or more horizontal black stripes across the screen that were not there before the repair.

The stripes are constant (don’t flicker) and appear on all sources (HDMI, TV menu, etc.), so it seems like a panel or connection issue, not software.

I’ve attached photos showing the lines.

From what I’ve read, this might be a loose ribbon / T-Con connection or a damaged TAB bond from reassembly.

Could anyone confirm what this looks like, and whether it’s fixable or means the panel’s damaged?

Also, would it make sense to take it back to the same repair shop and ask them to recheck the ribbon/T-Con connection?

Any advice would be appreciated - thank you