"Searching" even with no SIM inserted.

Hello. This can be a baseband ic issue I believe. The problem would be it requires soldering skills,and a heat gun. It could be a software issue,but I DOUBT it. If the baseband ic is loose,it can cause this soft of issue. If the phone is dropped very hard….or RUN OVER BY A CAR!!!!!….it could loosen this chip.

if you can’t do this repair,I recommend suggesting to the customer to contact irehab. It is owned by Jessa Jones. She is very good at repairing iPhones. This is her specialty. She is very nice,makes helpful YouTube videos,and is well known amongst ifixit and the soldering communities. She is the best iPhone repairs lady I can think of. The generally can repair the phones.

I cant even guarantee it is the baseband. It could be something else. Jessa would be able to pinpoint the problem and replace the part.

If you need anything else,let me know. Again,Jessa Jones is the way to go for your customer.