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10-07-2019 12:34 PM
Operating System: Microsoft Windows 10 (64-bit)
Hi, I've got an old Z820 workstation, and sometimes the system fans stay on full blast for no apparent reason - there's no workload, the system temperatures are all low, yet the fans are on full blast. Other times, they only come on under load. Any ideas why this might be, and whether anything could be done about it?
7 REPLIES 7
10-07-2019 05:05 PM
when the fans go full speed check the ambient air temp using the HP advisor program
your ambient air temp sensor (located in the power cable) or the circuit on the board may be failing
search this forum for numerous previous posts on this for more information
10-08-2019 08:29 AM - edited 10-08-2019 08:32 AM
you can also try replacing the sensor in the cable, it's near the button end covered in black heatshrink, and it's a common npn transistor you can use a 2n3904 or a 2n222a plastic body transistor as a replacement
note that the existing transistor will have two leads connected together and a single lead connected to colored wires, match the existing leads to the replacement and also note which lead connects to which color wire
you might also be able to use the z620 power cable on the z820, i know the z600 cable length will fit the z800 just barely
10-10-2019 09:37 AM
Thanks, but I'm not really up to soldering! I've been looking to get a new part, but I can't find it on HP.com, and I don't really want a refurbished part, in case it's duff as well. As far as I can work out, the part number is 644320-001 and/or 644320-002? But I can't find it on HP.com?
10-10-2019 02:58 PM
if hp still has stock it will be over 100.00 for the part
buying it from major companies who are HP authorized will be much cheaper
there is nothing wrong with buying used parts from people parting out systems on ebay as ebay will stand behind any sale where the seller says a part is in working order and refund the purchase price if the sold part is non working
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