Optimal repair of HP 250 G6: overheat, cooler, display frame

There are some issues with the notebook HP 250 G6 running on Linux, which may probably result in the need for cooler fan cleaning and replacement of thermal paste.

I need to do anything to prevent the blank screen after repair, as I have no resources for alternative notebooks to work on.

I found these links to similar repairs: HP G62-453 disassembly for cleaning and thermal paste, HP Probook 6450b Fan Cleaning & Thermal Paste Replacement. Here are the links to HP service documentation: manuals list, HP 250 G6 Notebook PC - Maintenance and Service Guide, User Guide.

Approx. 3 months after the 2-year warranty period ended, a crackling-type sound from the cooler fan area began occasionally to appear upon booting the notebook, as if the fan was rotating with some obstacles. Sometimes it ramped up so loud that I needed to reboot the laptop several times, shaking it mildly up and down. The sound was apparently associated with an ambient temperature being continuously rather low, like ~+17°C in winter months, especially as I had been leaving the laptop closed overnight on a table without placing it in a protective bag, at ~1 meter to the side of a heating tube and radiator. Some time later I began to place the laptop in a protective bag every day overnight when not in use. But after relatively normal work in summer months, one day when it was +13°C of ambient temperature the crackling sound reappeared.

This HP laptop also has a ~2x20 cm outlet vent grid at the bottom, in addition to the major ventilation outlet slot in the top left area near the cooler fan. So all this time I had been using an accessory ventilation USB pad, on top of which the laptop was always placed. In some cases of possibly intensive RAM and CPU usage the temperature increased from ordinary ~30-35°C to 50°C and somewhat similar sound from the cooler fan then arised (as if it was rotating more intensely), the laptop would then generally get into a “frozen” state, which could be resolved either by reboot (more often), or by waiting for ~20 minutes for a mouse cursor/keyboard to be activated.

There also have been some sounds from the DVD optical drive such that as if the drive was going to be ejected, though I didn’t press the button to do this. Recently I noticed that these sounds from the DVD drive appear to be triggered by somewhat strong enough physical force applied to the laptop: like moving it abruptly in horizontal plane or typing with somewhat excessive physical force on the main keyboard. But the drive itself seems to work normally (at least for reading DVDs).

There also is an issue with left hinge cover ((4) on p.23 of the Service Guide), probably after a tiny piece of candle wick with wax accidentally got into this area. On the hinge kit ((5) on p.23 of the Service Guide) there appeared some bending of the metallic frame long horizontal part, due to which the display bezel ((1) on p.23 of the Service Guide) in the bottom left area is not seated flush to the raw display panel (3). Some time earlier, upon opening the display lid of the notebook to power it on, the display bezel in the left bottom was retracted by ~2 mm from the display outer back lid by some obstacle in the area of the left hinge cover (4), so that to open the notebook I needed to hold the display bezel (1) and the back lid together. I began to leave the notebook with the lid opened upon non-usage. Now I can’t actually close the lid at all, as the display bezel (1) in the bottom area near the left hinge cover (4) prevents closing the lid. There appeared to be some free ~1-2mm piece of plastic inside the area of the left hinge cover (4).

So currently I have tech grade isopropyl alcohol (CAS Nr. 67-63-0), 2 balloons of compressed air for dust removal, a set of plastic tools to dismantle computer parts, antistatic gloves, wireless antistatic bracelet, ProsKit 30pcs precision screwdriver set. My questions are the following:

1) Do I need additional antistatic containers or pads to hold the dismantled parts (as mentioned in the User Guide and Service Guide)? Can I place them just in carton boxes or on any wooden/paper non-conductive surface? (taking into account, that most probably I may need to only dismantle the cooler fan and the copper tube, diverting heat from the CPU to change the thermal paste).

2) What is the optimal cleaning agent for display frame (bezel) parts, and elsewhere necessary in this situation for the cooler fan and thermal paste areas? The guidelines in the User Guide p.48 are inconsistent: “Use the following products to safely clean your computer: Dimethyl benzyl ammonium chloride… If you are not sure that a cleaning product is safe for your computer, check the product contents to make sure that ingredients such as alcohol, acetone, ammonium chloride, methylene chloride, and hydrocarbons are not included in the product.” So can ammonium chloride be used or not? Can I use tech. grade isopropyl alcohol?

3) Apart from what is mentioned in the 2 ifixit links on HP repair, what else can I do to ensure that the only notebook suitable for work would be fine after disassembly?

4) If a thermal paste replacement needed (and I’ve read on ifixit that thermal paste replacement is needed for notebook generally every 3-5 years), what thermal paste would you recommend?

Thank you very much