BTO/CLEVO P950ER repair help needed :)

[revex666]

Re: BTO/CLEVO P950ER repair help needed

both are 3.4 ohms

[mon2]

Re: BTO/CLEVO P950ER repair help needed

So there is a shorted component on board - hope it is not the CPU.

Would you have a DC power supply?

If yes, dial it up to 1 volt and inject it onto this same main power rail and monitor the current draw and look for who is heating up.

Just finished a repair a few minutes ago - A1466 unit that had a sudden death. The ACN / ACP junctions had 0R3 ohms to ground. After injecting 1 volt (need to keep the voltage as low as the lowest power rail (ie. so CPU does not get killed in case it is still alive) -> one of the many tantalum caps split open under the process. That is, over time, the polarized tantalum caps do end up 'shorting'. Whomever is shorting will heat up.

After removing the shorted cap -> unit is once again functional.

[revex666]

Re: BTO/CLEVO P950ER repair help needed

i have this power supply: https://nl.aliexpress.com/item/10050...d=WMJckJ2jHoLp

I bought it for another project (anodizing steel), but i presume this will work. i never did this before so I will read a bit about how to inject voltage and what to look for. Looking forward to try it

[mon2]

Re: BTO/CLEVO P950ER repair help needed

Good power supply. It will work fine.

Dial it up to 1 volt (not higher) for the voltage. Allow for the current to be as high as possible.

You do not attach the laptop power supply while performing this DC power supply injection.

Then red power probe onto ACN or ACP. Black to ground. The current should spike -> what is the current showing on your power supply? This process will heat up the component with the low resistance. Hope that it is a capacitor that will heat up and crack under pressure. Otherwise, it could be the CPU but the heatsink will need to be removed to view if that part is the defective one.

I know of a good video to learn about this process on youtube...will see if I can find it.

Found it:

https://www.youtube.com/watch?v=wp1dPG9_N1w

[revex666]

Re: BTO/CLEVO P950ER repair help needed

so I watched the video. Interesting guy and I will learn a lot more from him in the future. However, he explicitly says: don't inject if you have more than 1 ohm resistance. because most likely there is no short or something else.
What is your take on this since I have 3.5 ohms?

[revex666]

Re: BTO/CLEVO P950ER repair help needed

So, i bought a thermal camera (i had finely a good excuse) and connected a wire to ACN and ACP.
With presets of 1V and 3A the board draws 0.8A and on both sides i did not see anything heating up. Whats next?