I work with the guy, he does computer repair on the side because it interests him, he doesn't really do it for the money.
Why did I trust him? Because when I said I had a laptop that I wanted him to look at that wouldn't power on, he said "Is it a Dell?" (he had no reason to ask that other than my statement that it wouldn't power on)
I responded"yeah"..."Ahh, yeah, I see it a lot, it's usually the motherboard, but sometimes it's a power supply, bring it in, I'll take a look." Came back the next day and said it was the motherboard, and that if I wanted to buy one online, he'd put it in, but it likely wouldn't be worth it...which it wasn't. I asked what I owed him for his time, he said "nothing"...I had to twist his arm to accept a couple bottles of homemade wine as a 'thank you'. So, considering he pegged it dead to rights just on his experience, I suspect he has seen it a lot with Dells, and not so much with others.