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Inspiron 7459 AIO: Thermal Sensor Out of Range
Hello,
I noticed that the fan on my Dell Inspiron 7459 was running high and low sporadically, so I ran the system diagnostic from the UEFI/boot, and it told me "one or more thermal sensors out of range"-- Are thermal sensors replaceable? or is this possibly an issue with heat-sink mounting?
I've added a picture with the error message on the top right. It appeared during the diagnostic, and then stopped the progress.
thanks for your help! I've checked the 7459 repair manual, but it does not mention anything related to the thermal sensor.
beamermt79
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December 12th, 2017 15:00
Hmm. First off, the thermal sensors are generally built into the motherboard and are not replaceable. If they are going bad, the motherboard has to be replaced. I would go into the BIOS and reset everything to default. Sometimes there is a setting in BIOS that gets a bit off. If that doesn't work and you are out of warranty, you can try re-seating the heat sink assembly and redoing the thermal paste and see if that works. If you are under warranty, i'd have Dell deal with it.
captainsparkle
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December 15th, 2017 15:00
Thanks for the tip! a closer visual inspection implies that the stand-off screws for the heatsink are glued onto the MB, and two of them have come loose, which is likely causing the temperature sensor to be out of range!
Can anybody confirm that the stand-offs nuts for the heatsink mounting screws are, as appears, attached to the MB with an adhesive?
unfortunately, it isn't under warranty any more, so I don't have the option have a Dell repair; but, I do have access to glue! :-) I used to have thermal epoxy somewhere, which seems wise since it is so close to the heatsink, but I'm reading that superglue fails above 100C once it is set. so I shouldn't reach that temp (I'd hope?)
Any thoughts or suggestions?
captainsparkle
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December 15th, 2017 16:00
Hello and thanks for the response!
The link to the manual is great. I see the captive screws as mentioned, but that isn't the part I'm looking at. In my case, what appears to be "un-glued" from the motherboard is what the captive screws thread INTO. (if that makes sense!). From the same manual, page 16, you can see a picture of the MB without any parts attached. I'm referring to the four stand-offs (I think this is a dated term; not sure what to call them now. The nuts that the captive heatsink screws would fit into?) that are on each corner of the processor.
Its those parts, that the heatsink captive screws screw into, that appear to have come loose. I've taken the MB out, and they do not thread through to the other side or anything--hence why I assume they must be glued in.
I'm guessing this is not a typically user-serviceable part-- but I'd really rather not spend $1000 to get a new machine when some new adhesive will do the trick!
beamermt79
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December 15th, 2017 16:00
Hello! So I just looked at the service manual and the only tape or glue it talks about is what covers the heatsink and the fan. The rest of the heatsink that is away from the fan is held down by captive screws. It is possible there is some sort of glue or something on the screws themselves, maybe to keep them in place, but it shouldn't just be a glue or apoxy that keeps the heatsink down. Here is the service manual; it should be on page 51. Make sure to read it CAREFULLY as it states there is a sequence in removing the screws and heatsink.
It could also be that one or more of the screws backed out. Maybe try gently tightening the screws?
beamermt79
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December 16th, 2017 12:00
Hmm.. I think I see what your talking about. Since they are captive screws, they should screw into a plate like device on the back of the motherboard. I'd see maybe about replacing the captive screws. This manual doesn't show what screws they are though so i would google it. If you want to try the heat resistant glue, you can do it, just be careful not to get it on the board.