Switch fan turning off while installing heatsink

[Seancarter78]

Having a bizarre issue with my switch, had to open the thing up to replace a dodgy LCD screen and a buzzing fan. While replacing the fan, the small flap on the motherboard connector flew off and got lost. After doing a bit of research and discovering this is a semi-common occurrence, I've inserted the cable into the connector and taped it down, seemingly working fine, but the issue appears when I try to install the heatsink

For some reason, when applying pressure onto the heatsink while screwing it down (or inducing it manually like in the attached video), the fan completely shuts off. I had suspected this was an issue with the new fan I was installing, but repeating the process on my old fan showed the same issue.



Any advice at all would be great, as I can't for the life of me figure out what could possibly cause this. It doesn't seem to be something shorting out, as protecting the metal parts with electrical tape doesn't make a difference. The fan cable is 100% secure and works fine before I install the heatsink, I just don't understand how missing a tiny bit of a plastic clip could be causing this kind of issue.

 

[Hayato213]

Why is your switch on when you are swapping out/replacing component?

 

[jkyoho]

you may check your cpu temperature before and after you put the press/screw down the heatsink.
Unless you short the fan connector, fan should not be running when cpu temperature under 43°C, I assume the pressure you did make solid contact and transferring heat out of CPU ,so when idle the fan stop.

 

[Seancarter78]

Why is your switch on when you are swapping out/replacing component?

Not on for the entire duration, but switched on and off multiple times during the process to ensure all of the new components were working. Didn't want to close the system up just to find a loose ribbon cable that I'd missed, especially considering opening and closing the switch repeatedly is super bad for the SD card connector.

 

[impeeza]

looking the way your thermal paste is applied and the fact you are manipulating the console with the battery plugged and turned on.

No wonder if a great damage is on the console, you could create a shortcut or even overheat your chip-set.

the fan is made to remove heat from the radiator pipe, and if it is not properly attached there is no heat dissipation, the pipe and radiator needs no only thermal paste but some press which is provided by the case and screws.

 

[Hayato213]

Not on for the entire duration, but switched on and off multiple times during the process to ensure all of the new components were working. Didn't want to close the system up just to find a loose ribbon cable that I'd missed, especially considering opening and closing the switch repeatedly is super bad for the SD card connector.

First thing you should have done was disconnect the battery when you are swapping out or replacing the component, you risk damaging motherboard component doing that.

 

[Seancarter78]

you may check your cpu temperature before and after you put the press/screw down the heatsink.
Unless you short the fan connector, fan should not be running when cpu temperature under 43°C, I assume the pressure you did make solid contact and transferring heat out of CPU ,so when idle the fan stop.

Good info, thanks for the idea. I was just booting into stock OS to test the screen etc, but I'll stick the whole thing together again and run a game with cfw to check the temps and see if it's working.

Post automatically merged: Nov 27, 2023

First thing you should have done was disconnect the battery when you are swapping out or replacing the component, you risk damaging motherboard component doing that.

I understand the risks in working with live electronics, but I've worked on plenty of handhelds without disconnecting the battery before swapping components. Removing the battery would be safest but I feel having the console completely powered down is acceptable when you consider how prone to damage the mobo connectors tend to be on older switches. I'd rather take a fractional electrical risk instead of fumbling and potentially breaking the delicate internals.

Post automatically merged: Nov 27, 2023

looking the way your thermal paste is applied and the fact you are manipulating the console with the battery plugged and turned on.

No wonder if a great damage is on the console, you could create a shortcut or even overheat your chip-set.

the fan is made to remove heat from the radiator pipe, and if it is not properly attached there is no heat dissipation, the pipe and radiator needs no only thermal paste but some press which is provided by the case and screws.

The thermal paste is definitely a mess at this point, it was a nice clean application when I started but I've been hung up on this problem for a few hours at this point and repeatedly removing and replacing the part has smeared that toxic crud everywhere

I appreciate the concern but the switch wasn't on for the duration of the repair, only for a few moments between component swaps to ensure everything was working. I noticed this issue after powering the console back up again.

 

[Hayato213]

I understand the risks in working with live electronics, but I've worked on plenty of handhelds without disconnecting the battery before swapping components. Removing the battery would be safest but I feel having the console completely powered down is acceptable when you consider how prone to damage the mobo connectors tend to be on older switches. I'd rather take a fractional electrical risk instead of fumbling and potentially breaking the delicate internals.

Then you don't know enough, as a general rule, always disconnect the battery when working with electronics, you risk killing the fan, the SD card flex with the way you do stuffs.

Post automatically merged: Nov 27, 2023

The thermal paste is definitely a mess at this point, it was a nice clean application when I started but I've been hung up on this problem for a few hours at this point and repeatedly removing and replacing the part has smeared that toxic crud everywhere

I appreciate the concern but the switch wasn't on for the duration of the repair, only for a few moments between component swaps to ensure everything was working. I noticed this issue after powering the console back up again.

I do agree with @impeeza that the thermal paste is a mess, you are lucky that it is on the other component on the board.

 

[Seancarter78]

UPDATE:

@jkyoho was completely correct, the fan was seemingly spinning up because it was detecting that the cpu was overheating, but applying the heatsink sucked out enough heat to turn the fan back off. Closing it up and booting up dark souls had the fans spin to life quick as could be. Truly a bizarre issue that I never would have even seen if I hadn't been replacing multiple parts at a time. To think I could have avoided wasting an entire afternoon if I wasn't so concerned about wearing out any more connectors.