Disassemble the whole thing into its component parts and clean. If you use water, use distilled water and let the part completely dry. Get some of those compressed air cans, q-tips, isopropal achohol, etc.
My dad got a used computer of of eBay alittle over a year ago. The nearest we can figure was the guy was a smokaholic. Everything was yellowish brown and smelled stronly of smoke, then we turned it on. It just go stronger. It was a fun cleaning job.
oh, if you can take the PSU apart and clean it real well. Especially the fan. Otherwise you'll still get wafts of odor. Same with the CPU fan or any other fans in the system.
