F4-424 Pro CPU overheating

[HeatherC]

I have submitted a support ticket but no response so far and just wondered if anyone of the forum can help.

I have a TerraMaster F4-424 Pro, The CPU was consistently reaching 95–96°C under load. During servicing I removed the large CPU heatsink and found that the original thermal pad/phase-change sheet had torn.

Does anyone know the exact replacement thermal-interface material, thickness and dimensions required between the Intel N305 CPU and the original heatsink. I do not want to substitute ordinary thermal paste because the heatsink appears to have a designed gap above the CPU

[TMzethar]

Sorry to hear you're having trouble with CPU cooling.
It's fine to use regular thermal paste.

[HeatherC]

After replacing the factory thermal material with thermal paste as advised, the F4-424 Pro powers on and the fan runs, but it no longer completes POST. There is no startup beep, no Ethernet link light, and no network response, even with all HDDs removed.

I removed the RAM and powered on the NAS. It produced repeated error beeps with no RAM installed. I then cleaned the RAM contacts with isopropyl alcohol, allowed them to dry fully and reinstalled the original RAM module. With the RAM installed, there is again no startup beep, no Ethernet link light and no network response.

I have reseated the motherboard and confirmed that the RAM retaining clips are fully engaged. Please advise the correct hardware diagnostic procedure and whether a CMOS reset is appropriate. I do not want to perform a TOS factory reset or risk the data drives.

[TMzethar]

If the problem really is hardware‑related, there's no point resetting TOS — it lives on the drives and won't fix anything. If you think the fan isn't spinning up properly, try setting it to high speed to see if that helps.

This looks different from what we saw before — seems more like a hardware issue now. Are you using the right power supply? And yes, you can definitely try resetting the CMOS.

[TMroy]

There is a possibility that a component was damaged during the disassembly of the circuit board, or that it was not reassembled correctly, causing the device to malfunction. If you are unable to identify the issue, please contact our after-sales service department to request a repair.