Anybody know? Just coming up with a bunch of Dell shops when search, not service centers.

I would ask in an official Dell store, by example in Central Airport, where an official service center is. If it´s a simple repair you can go to every other repair service.

You will need to call a central Dell number for Thailand. They will in turn give you the whereabouts of a Chiang Mai technician. There is no dedicated Dell service center in Chiang Mai. 

You can try getting Dell's number from one of the stores that sell their products. That is what I did. It may also be available online.

I ended up getting the job done at Advice, instead of the Dell authorized techy. It was much cheaper, and I had a good feeling after speaking with Advice.

On the rare occasion that I have had to use any type of repair or warranty work on any of my Dell products (more than 15 years using Dell in Thailand) this is who did the work for me:  http://www.svoa.co.th/