Chipset no longer works?

My notebook has a permanent black screen, so I took the notebook to diagnose errors and was told that the graphics card is 100% broken. That's why I got a new MXM graphics card with the same connector for the graphics card slot and got myself Ordered thermal pads and thermal paste, which will arrive in a few days. In addition, at the service I was told that the mainboard had also been tested and 90% were problem-free and 10% were not stable, so the service man claimed that the chipset could also be defective His explanation for this claim is that the graphics card only breaks with the heater (don't know what he means by heater) and the chipset and graphics card are so close (i.e. In the mainboard) and are cooled by the same cooling system Claim, because when starting the LED goes on and the cooler goes on as usual, only I have a permanent black screen

He was probably referring to the vapor chamber. It may be that this has a bulge and therefore could no longer cool properly. He suspects that the notebook has overheated and the vapor chamber has warped. If the Vapor champer also cools the chipset, it can be damaged by heat or deformation.

Which CPU is built into the notebook?

In the PC sector, the term "heater" doesn't exist at most, but it can't be translated 1: 1. The heater usually refers to the heat sink.

Intel Core Duo T6500

And what does that mean

This means you have to assess whether your heat sink is still making sufficient contact with all components or has risen and no longer has sufficient cooling surface.

If you now expect an answer whether your chipset is still working or not, no one can answer that here. Since you've already ordered a new graphics card, install it and test it.

Yes, I wanted to install the graphics card but I have to wait until the thermal paste and the thermal pads arrive

Since the Core 2 Duo T6500 does not have an integrated graphics core, and with suitable mainboards for this processor only bring an iGPU with certain chipsets, the notebook can't display a picture without a dedicated graphics card.

On this old platform, the chipset still consists of two parts; a north / and a southbridge.

The Northbridge connects the central processor with the AGP / PCIE for graphics hardware iGPU and eGPU, with the RAM and the Southbridge. On the southbridge hang among others The interfaces for drives, peripherals, sound and the BIOS ROM.

If there's an error at a critical point in one of these two chipset parts, the processor may not be able to access the BIOS, RAM or other components (depending on the location of the error), which may even cause the BIOS initialization to fail can.

What the expert meant by "heater" is the so-called "heat pipe". This is a hermetically sealed copper pipe with the finest capillaries and a gas / liquid mixture. This tube connects the cooling fins with the coldplate (s), which in turn are screwed onto the chips that are to be actively cooled using thermal paste. (at least the CPU and the northbridge)

If a heat pipe is (permanently) thermally stressed too much, it can be structurally damaged on the inside and lose its special heat transfer properties (a kind of heat pump function).

Microchips can withstand relatively high temperatures of up to ~ 100 degrees (and even above) without any problems, but too much heat is not beneficial to the substrate in the long term, which means that at some point, even in the millions of circuits of such complex chips, errors can increasingly arise due to atomic migration. One mistake in the wrong place, and that's it for the chip.

With you, however, there does not seem to be a total failure of the CPU and chipset, otherwise the expert could hardly have said that 90% of the functionality was still there. (Stop next to it only 100% defect in the graphics unit)

I hope you have at least ordered the same MXM graphics card that was originally installed in the notebook. (i.e. An identical graphics processor) If you want to build in something more modern and more powerful than the original one, there may otherwise be an electrical overload of the MXM interface with its own power supply, or and / or PCIe incompatibilities between the card, BIOS and controller.