Reusing thermal grease on CPU?

[GS]

I need to replace the motherboard CR2032 battery on a Dell USFF
machine. But to access the battery you have to remove the heatsink!!

You can't remove the CPU+heatsink as a single item as the cpu
retention lever can't be released until you've removed the heatsink.

The handbook blithely says regarding the heatsink:

"Lift the heat sink/fan assembly, and remove it from the computer.
Lay the assembly with the fan facing downward, and with the thermal
grease facing upward."

"Installing the Heat Sink:
1. Place the heat sink into the chassis.
2. Tighten the captive screws to secure the heat sink to the system
board."

No mention of replacing the thermal grease! Will this work or should
I splash out on some thermal grease + solvent to remove the old
stuff?

It seems crazy that the coin cell is positioned under the heatsink
assembly. I bought this machine as "A1 refurbished" from Morgan
Computers but their "refurbishment" evidently didn't stretch to
replacing the mobo battery as it failed in less than 2 years despite
the pc always being plugged in until I needed to move it recently.

[Gordon]

Post by GS
I need to replace the motherboard CR2032 battery on a Dell USFF
machine. But to access the battery you have to remove the heatsink!!
You can't remove the CPU+heatsink as a single item as the cpu
retention lever can't be released until you've removed the heatsink.
"Lift the heat sink/fan assembly, and remove it from the computer.
Lay the assembly with the fan facing downward, and with the thermal
grease facing upward."
1. Place the heat sink into the chassis.
2. Tighten the captive screws to secure the heat sink to the system
board."
No mention of replacing the thermal grease! Will this work or should
I splash out on some thermal grease + solvent to remove the old
stuff?

Best practice is to do the solvent new grease route.

If the old grease is still soft then you might get away with it.

Also how hard are you going to drive the CPU?

Post by GS
It seems crazy that the coin cell is positioned under the heatsink
assembly. I bought this machine as "A1 refurbished" from Morgan
Computers but their "refurbishment" evidently didn't stretch to
replacing the mobo battery as it failed in less than 2 years despite
the pc always being plugged in until I needed to move it recently.

Batteries self discharge so they go flat even with no load on them.