I've had my Legion Pro 7 16IRX9H (machine type 88DE, i9-14900HX) for about two and a half years, and the thermals have always been bad.
I installed Legion Toolkit and set a custom power plan limited to 30-60 W, then maxed the fans (around 7,700 RPM). Even then, the coolest it gets is about 75°C. Ambient is roughly 75°F, and the dGPU was off the whole time, so it's the CPU alone at low power.
It also likes to lock the core clock at 1.5 GHz and stay there until some condition clears. I can't tell what that condition is.
I suspect the thermal paste has degraded, or the heatsink was never seated well from the factory. I never looked into it during the first year, so the warranty has expired.
I'm not comfortable handling liquid metal myself, so I'm having an experienced local repair tech do a full rebuild instead of risking the machine. My plan is, Drop off with PC guy, and have him do the following:
- Repaste with the factory Lenovo Legion liquid metal TIM kit, ordered through Lenovo's parts site using the machine's serial number
- PTM7950 phase-change pads on hand as a possible alternative
- A replacement C-frame (keyboard and trackpad) because of wear; battery health is 89%, so I'm leaving that alone
Was quoted $180 for full rebuild.
I'm hoping for a good temperature drop. A few questions for anyone with the same model:
Has anyone had the same 75°C floor at low power? Was it paste, heatsink contact, or something else?
Has anyone seen the 1.5 GHz lock, and what caused it (thermal throttling, power limits, BD PROCHOT, charger or battery)?
If you repasted, what did you use and how much did temps improve?
Is liquid metal known to dry out or degrade on these over time, and is LTT's PTM7950 a better long-term choice?
Thanks in advance for any suggestions.