[global] Aliexpress: US$150 Razer Core V2 board -> add ATX PSU, TB3 cable for 65W PD TB3 eGPU with extra PCIe slot
In some better news: I now have a multimeter and I've measured the voltage of the 10 pins in the 'to LED' connector.
While the PSU is off, two of the pins output a voltage, which must be derived from the 5Vsb.
One pin puts out ~3.3V, and a second ~2.7V (from memory, true voltage may differ slightly).
This voltage must have been transformed on the mainboard somewhere: I have checked that none of the other rails have output and the 5Vsv is indeed outputting 5V.
I can't remember which pins these were. I'm waiting for resistors to arrive so I can test grounding these, hopefully bypassing the hall/reed/magnetic switch.
Still hoping to find a connector to breakout the 10 pin as I cannot solder that precisely! I've asked Razer Support for one but do not hold out much hope for that happening.
So with the power supply plugged in, but turned off, I've confirmed the only output in the 5Vsb. I've recorded the voltages from the 10 pin LED connector in the table below in this state, including the resistance between each pin and ground. These read left to right as per the photo.
Only the 2.76V pin 4 will power up the PSU. This works when I run it through a 10k resistor to pins 2, 5 and 6, and to the ATX ground. However this only half starts the PSU. It will start briefly, then stop. This causes the PSU to start outputting the 12V rail, but this is a pulse, then stops, then starts again.
This supply has a Brown 3.3V sense, which I have connected directly to the 3.3V rail orange wire. I get the same result without this. I have also tried different resistor values from 100k to 100R.
In summary, the 10pin definitely operates the switching function, through pin 4, but something is still missing.
Could it be that I need to ground the 3.3V Pin 3 as well?
@lefuturdelavenir, Thanks. I have just tried pulling down pin 4 and the POWERON to ground, the latter through a 10k resistor again.
The PSU powers on with constant 12V supply, but there is no PD delivery. Without the POWERON pulled down, the PSU fires up in pulses but it does briefly deliver PD.
I haven't yet managed to tried pulling those pins up- still quite hard without a ribbon cable to break out this header.
Interestingly, when I directly ground the POWERON, while the PSU runs constantly, I do not get any PD to the laptop, even when I ground pin 4 of the LED connector.
In contrast, when the POWERON runs to the JST connector, and I then ground the pin 4, I get pulses of power delivery.
Next step is to try and get a ribbon connector from Razer. Alternatively I will consider buying the LED board from Aliexpress, but I have not been able to confirm that this comes with the ribbon connector, which would not help me get any further.
Where does the 5 pin connector here lead?
And can anyone confirm if the black chip seen here is the magnet sensor, and that this is indeed on the LED board?
@lefuturdelavenir, great, so not needed for the poweron.
Unfortunately I have never actually seen a Core (of any version) in the flesh! So I can't confirm these things without the rest of the Core V2. I don't know what components there are other than the teardown in this site's review! So this is a fun/challenging exploration...
I believe the LED connector uses the JST-SH 1.0mm pitch format in a 10 pin connector. I have ordered these, which means I can practically work with each pin. Hopefully this will allow me to finally bypass the power on...