Jeff is the biggest sweetheart you will find in this business. He's helped me out twice now, and didn't ask for a dime. He once helped me unjam a SIM card from a second-hand phone I had bought, free of charge. And just today he helped me with my laptop, pinpointing the issue which resulted in a reformatted harddrive, but a working laptop in the end. Once again he tried to refuse payment, but since he literally saved me 2 days worth of work, had to give some compensation.
He's a bit softspoken, but he's an extremely honest and kind man who knows what he's doing. I'd highly recommend him. And seriously, if he tries to refuse your money, at least give him something for his time. Aren't enough good people like him out there.