Once had a lady at work tell me she couldnt figure out what was wrong with her machine. Told her I'd take a look at it at my nominal $35 fee.
Get the machine, it unmistakably smells like a Marlboro factory. Take the computer apart, it is ORANGE. Thick layer of tobacco tar coated fucking the entire inside of the machine, and the smell was nauseating. Lady was a chain smoker and smoked multiple packs a day sitting in front of her computer playing second life (this was only a few years ago, and yes she was very fat). Saw telltale discoloration on the GPU bracket. Tried to furn the fan, no only would the GPU fan not budge, but no fans in the system would either.
Told here this thing needed to be nuked from orbit, and to knock off the smoking in front of her computer (and smoking in general). She said she couldn't afford a new machine.
Here's the moron part: I said id clean her old one, but it was gonna cost her $250 before the cost of parts to clean this sludge out. Of course she said yes.......I'm a dumbass.
So I spent the next 2 days cleaning this fucker. 24 hour bath of a water/bleach mix softened the tobacco tar tot he point it could be peeled off (ewww) and re-whitened the case. Took the whole kit and caboodle apart and cleaned EVERYTHING. Then charged her another $200 for new fans and a new (to her) GPU.
Not worth it. Should have outright refused to work on the damn thing. I learned my lesson though, because she tried to bring me this thing again for the same problem last year, and I told her she was SOL since she couldnt stop smoking, she was just going to kill it again.
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I would guess your RAM upgrade calamity could have been caused by using "PC3L" instead of "PC3" RAM, PC3L is low-voltage 1.35V and PC3 is regular 1.5V.
HP and DELL provide service manuals for their PC products and they can be downloaded for free, great when upgrading or changing BIOS settings.
Gonna stop you right there. Putting DDR3L memory into a DDR3 socket will NOT, i repeat, will NOT cause it to go up in smoke. ABSOLUTELY NOT. DDR3L memory can still run at 1.5V if the system refuses to use 1.35V. It's built into the JDEC spec for DRAM. All DRAM must confirm to certian specifications, and running at nominal voltage is one of them.
EDIT: Smaug beat me to it. Loose power cable might be more likely, even then I've never seen a machine short out that badly from a loose connector. Only time I've ever seen magic smoke is when the power supply takes a gorilla sized dump.
