We're based in East London and have been working on Apple Macs for 12 years, doing all sorts of Repairs and upgrades.
No repair is too large or too small and I do not charge for full diagnosis and quotations. So if you decide you don't wish to go ahead with the work it won't cost you a penny.
I also have a call out service and am available day or evening. Many repairs and upgrades can be done straight away while you wait and because I work from home my prices are far lower than Computer Repair shops.