HP ENVY 13 almost dead.

[Francisco.s]

Hi, have a HP ENVY 13 with motherboard CINNAMON-6050A2867801-MB-A01 that is almost dead. There's no schematic for this board.

There are +3VALW and +5VALW.

Also there are activity in bios pins, but only when power connector is plugged.

There also some pulses (only for less than a second) in U60800, and the 1UH coil near this pwm chip.

I tried to find the datasheet for this chip, but no luck.

It's a 24 pin qfn but seems to have only 23 pin. (pin 10 does not exist)

Anyone have information about this chip?

S275 5335:

[mon2]

Re: HP ENVY 13 almost dead.

https://m.aliexpress.com/i/32951344033.html

[Francisco.s]

Re: HP ENVY 13 almost dead.

https://m.aliexpress.com/i/32951344033.html

Thanks mon2, it's exactly the same chip.

I've found that PGOOD (pin 1) is always at low level, but there's no shortcircuit to gnd in that pin. (diodo mode reading is good)

Pin 2 (EN) goes high for half a second, and only when power connector is plugged.

I think PGOOD signal is brought to gnd by other pwm circuit, most probably ddr pwm circuit.

I will check and post again.

[mon2]

Re: HP ENVY 13 almost dead.

PGOOD is most likely an open-drain / open-collector design. This means that this part will output a logic low but no logic high. The 'soft high' is defined with an external pull-up resistor that MUST be present on this line.

So PGOOD will be LOW while the power is NOT good or the threshold is reached.

So why use open-drain / open-collector ? This method can be used to logically OR together other devices onto the same line. So multiple devices can mate with to this line without harm to each other. In short, any device that outputs a '0' = LOGIC LOW, then they win and will keep the downstream device in RESET mode. As long as ALL devices on this line are floating the line, then the pull-up resistor will pull the line HIGH and RESET is released.

Then PGOOD will float this line when the power is OK = GOOD. This is why the external resistor must be present to pull the line to the logic high.

So check if PGOOD is low WITHOUT this IC. If this line is LOW without the IC then you have an external device causing this event. This line should be HIGH '1' logic level without the IC installed.

You can study any charger IC / switching power IC to review the power_good signal and how it works for a deeper explanation - it will be the same for this device.

[Francisco.s]

Re: HP ENVY 13 almost dead.

So check if PGOOD is low WITHOUT this IC. If this line is LOW without the IC then you have an external device causing this event. This line should be HIGH '1' logic level without the IC installed.

I will try with chip removed an check PGOOD level.

Thanks for your good explanation.

[Spider1211]

Re: HP ENVY 13 almost dead.

Avoid removing chips without understanding their function properly. Most regulators are used to control/switch external mosfet to produce certain voltage from a higher voltage (buck regulator). You should NEVER power a board if you remove the driver chip because the mosfet gate becomes floating. The voltage on the gate will eventually rise enough to open them causing them to conduct which in turn may send high voltage to the output. Sending 19V to a 1.8V chip for example will kill it.

Also note that pgood can be of 2 types; active high and active low.

Active high means the signal (pgood) will be a high voltage (3.3v usually) if the signal valid. If there is an issue, the signal is pulled low. Active high is the most common one.

Active low is the opposite and is usually denoted by a # (for example pgood#). Signal is high if there is an error and low if all is good.

In your case, referring to the chip reference above, said mosfet and driver are built into 1 single chip and therefore OK to power on.

If pgood is appearing then going away, its very likely because its sensing a fault (could be a short somewhere).

Before removing anything, I'ld suggest you do some troubleshooting first. Measure resistance to ground on all coils and report back.

[Francisco.s]

Re: HP ENVY 13 almost dead.

In your case, referring to the chip reference above, said mosfet and driver are built into 1 single chip and therefore OK to power on.

You are right, in this case there are not external mosfet, so I think it's safe to test it with chip removed.

Thanks for your help. I'm going to test it today, I will post results.

[Francisco.s]

Re: HP ENVY 13 almost dead.

I will try with chip removed an check PGOOD level.

I've made some measurements with chip removed and I'm get a bit confused.

It's weird but there are no connection between pin 1 ( PGOOD) and any point in the board.

Diode mode and ohms mode readings are open or infinite. The pin 1 pad goes to nowhere except to other pad to a nonexistent smd resistor.

Working without schematic is a nightmare.

I have checked other schematics like Quanta ZAS and lenovo 120S-11&14IAP, and G5335 chip have different works. Quanta ZAS uses it to generate VDDP_0.95V_S5, and in lenovo 120S generates +VDDQ. (DDR_OUT)

Both schematics have PGOOD signal connected to their respective power good circuits.

I don't think in this motherboard (CINNAMON-6050A2867801-MB-A01) G5335 chip generates +VDDQ or any ddr voltage, but not sure about it.

There are other chips from the same manufacturer as G5335 in the board but can't remember references now. I will post the exact references and continue with the investigations.

[Francisco.s]

Re: HP ENVY 13 almost dead.

I don't think in this motherboard (CINNAMON-6050A2867801-MB-A01) G5335 chip generates +VDDQ or any ddr voltage, but not sure about it.

There are other chips from the same manufacturer as G5335 in the board but can't remember references now. I will post the exact references and continue with the investigations.

Confirmed that G5335 does not generate +VDDQ, there is another chip to power ddr memories chips, its reference is G5388, and it is equivalent to APW8861.

There are datasheet for the last one but didn't find for G5388,

The output coil of G5388 is connected to most of ceramic capacitor near ddr chips.

Looking at the datasheet, pins 5 and 6 are the enable signal for S3 and S5, but none of them receives voltage to enable the G5388, (probably cpu do not generate PM_SLP_S4)

Any help will be appreciated.