Laptop repair + Portable Hard Drive recovery recommendation?

Hello, my Windows laptop seems to have an electrical short/hardware problem. Also, I have a Seagate external portable hard drive which needs to be fixed, or the data from it recovered if it’s not repairable. Does anyone know of a service in East/North/Central London which is NOT a rip-off? We, and our friends, have had bad experiences with rip-offs when having hardware repaired in the past. Thank you.