HI folks - i m new here and looking for help. I have about a 6 YEAR old HP520  (all in one desktop) ,  Intel I5 chip - been a great machine for my family.  About 6 months ago, i started to notice a noise that sounded like the fan,  and a few months after that,, it started to run slowly,,  too slowly to complete even common tasks effectively ( 30 seconds to open email). So, I installed CoreTemp, small software to monitor the temp of the procesors and learned they were all redlined after a short period of time.   So, i replaced the fan - in that process saw a lot of dust on the grill at the end of the duct that directs air over what looks like a big copper tube which ends directly over the processor.  I guess, being copper it conducts heat about 12 inches to the fan port where it is cooled.   So, when i replaced the fan, a vacuumed all the dust out,  etc. and put it BACK togeher  full of hope...     well, it does operate at lower temperatures for a little longer with the new fan, the overheating problems came back quickly nonetheless. TO confirm the problems with slow performance are heat related, i placed a wet cloth on the copper tube to dissipate heat and monitored the performance and temp and it was was fine,,  temp stayed normal and performance was fine..  took the cloth  off ( and it was HOT) temps went to redline and performace into the tank

anyone have any idea why the overheating issues continue?  I did run the HP DIAGNOSTICS as well and all was fine   - i am not sure how indepth these tests are, but indicated all was well..

any help appreciated. I had a i5 laptop that was running to 85C and I had to replace its heatsink which was also heatpipes. Somehow some of the ALCOHOL inside the tube must have leaked out through a poor solder joint I am guessing and so it wasnt working as it should have. I replaced the thermal compound and that didnt help. Replacing the heatsink is what fixed my issue similar to yours.that makes sense to me -  i assume the heat sink is the "copper tube" intended to transfer heat to the fan housing?

thanks very muchYes ... The tubes known as heat pipes draw the heat away and here is more info on how they work: https://en.wikipedia.org/wiki/Heat_pipe . Any little microfracture and they fail, and fail to get rid of heat.excellent and thank you for the wiki link  -  very informative - makes sense to me after reading. i will tear the thing apart, get the correct replacement number and order...


CHEERS and have a good weekend.