HP ProBook 650 G4 Blinking Amber Light

[sect-sin]

Hello,

I have a HP ProBook 650 G4 with a continuously blinking amber light, no post issue. The motherboard version is CHROMIA-6050A2930001-MB-A01(A1), no schematics or boardview is available for it.

What I have done so far is the following: There is no short anywhere on the board, and all high and low MOSFETs check out fine (I checked resistances across G-S-D as well as diodes). BIOS and EC both get 3.3V, I tried reflashing both with fixed versions from hoaca, no change.

I measured all coil voltages, see attached image for values, some get voltages, some do not. 19V stops at one of the MOSFETs, which shows some strange values, see image for measurements (MOSFET is a SM3335PSQG). The charge controller is an Intersil / Reneas ISL9538H. Unfortunately there is no Datasheet available for it, so I do not know which pins to measure (see image).

Can anybody help me in diagnosing this? Thank you very much in advance.

Cheers,

sect-sin

[mon2]

Re: HP ProBook 650 G4 Blinking Amber Light

Attached is a reference schematic of the ISL9538 to get started.

[sect-sin]

Re: HP ProBook 650 G4 Blinking Amber Light

Attached is a reference schematic of the ISL9538 to get started.

Mon2,

Thank you very much, this is great. What should I measure (with utmost care most certainly)?

Cheers,

sect-sin

[mon2]

Re: HP ProBook 650 G4 Blinking Amber Light

From the internet...

Blinking Amber: Indicates a battery that is the only available power source has reached a low battery level. When the battery reaches a critical battery level, the battery light begins blinking rapidly.

Locate all mosfets near this IC.

Post their top side markings. We want to learn if they are N-channel or P-channel mosfets.

[sect-sin]

Re: HP ProBook 650 G4 Blinking Amber Light

From the internet...


Locate all mosfets near this IC.

Post their top side markings. We want to learn if they are N-channel or P-channel mosfets.

The green ones are all N-channel AON6380, the red ones are all P-Channel SM3335PSQG. On the bottom side of the PCB, there is another SM3335.

[mon2]

Re: HP ProBook 650 G4 Blinking Amber Light

In the posted picture of the logic board, the top left side of the isl regulator appears to have shorted solder pins.

Has this board been worked on already?

The other pins on the device are clean and you can see the pcb between each of the pins but not the left side.

Suggest to flux and heat with hot air to clean up the soldering. Go in circles and the solder will melt and self align into the pcb pads. If it is only a bad angle of the picture then ignore.

[sect-sin]

Re: HP ProBook 650 G4 Blinking Amber Light

In the posted picture of the logic board, the top left side of the isl regulator appears to have shorted solder pins.

Has this board been worked on already?

The other pins on the device are clean and you can see the pcb between each of the pins but not the left side.

Suggest to flux and heat with hot air to clean up the soldering. Go in circles and the solder will melt and self align into the pcb pads. If it is only a bad angle of the picture then ignore.

I have been working on the board, I replaced one of the SM3335 Mosfets, because I thought it was faulty (but it was not). So flux got on the ISL, but I have not touched it (see attached). There is not short, I can confirm.

[mcplslg123]

Re: HP ProBook 650 G4 Blinking Amber Light

Your problem seems like 19V not crossing the 1st dc-in mosfet. It wont unless the gate voltage is correct. Measure , with care, voltage on pin 17/18/19/20/24/8 and post here. I hope u have checked the dc-in fets for shorting. Check Resistance on CLR also.

[sect-sin]

Re: HP ProBook 650 G4 Blinking Amber Light

Your problem seems like 19V not crossing the 1st dc-in mosfet. It wont unless the gate voltage is correct. Measure , with care, voltage on pin 17/18/19/20/24/8 and post here. I hope u have checked the dc-in fets for shorting. Check Resistance on CLR also.

Hi mcplslg123,

Thank you for helping. I have measured everything, results are the following:

DCIN (17)=19,15V
VDD(18)=5,129V
ACIN(1)=3,866V
CMIN(20)=0V
ACOK(24)=3,305V
VDDP(8)=5,123V

I can confirm that none of the MOSFET's are shorted. I have attached a further picture showing what values both P-channel MOSFET measure.

Unfortunately I have no idea where the current limiting resistor is. If you can tell me what to look for, I will gladly measure.

Cheers,

sect-sin

[sect-sin]

Re: HP ProBook 650 G4 Blinking Amber Light

Hi,

I forgot to attach the photo, here it is.

Cheers,

sect-sin

[mcplslg123]

Re: HP ProBook 650 G4 Blinking Amber Light

All the measurements seems good. Try replacing the charging IC.

[sect-sin]

Re: HP ProBook 650 G4 Blinking Amber Light

All the measurements seems good. Try replacing the charging IC.

I have ordered a replacement, unfortunately none of my donor boards have it. Will be here in a week, will let you know the outcome.

Another thing came to my mind, as mon2 has already mentioned it. Is it possible that this notebook will not run without a working battery?

Cheers,

sect-sin

[mcplslg123]

Re: HP ProBook 650 G4 Blinking Amber Light

Very unlikely. It should work without battery.

[Sephir0th]

Re: HP ProBook 650 G4 Blinking Amber Light

Since some basic step down voltages like 5V, 3.3V and 1V are present and also ACOK is deasserted, I see no point to troubleshoot the DC-IN Circuit tbh. For the MOSFET in question near the NVDC circuit for creating the Main power rail you have to use your multimeter to to check to what it connects. Follow the rails and also look for connection the the charging controller just to be sure. It's hard to work without schematics but in these cases the multimeter is your only friend. if you don't want to troubleshoot the board for years you have to go ahead and check some things by yourself.

Do you have 3.3V at the power button by any chance?

[sect-sin]

Re: HP ProBook 650 G4 Blinking Amber Light

Since some basic step down voltages like 5V, 3.3V and 1V are present and also ACOK is deasserted, I see no point to troubleshoot the DC-IN Circuit tbh. For the MOSFET in question near the NVDC circuit for creating the Main power rail you have to use your multimeter to to check to what it connects. Follow the rails and also look for connection the the charging controller just to be sure. It's hard to work without schematics but in these cases the multimeter is your only friend. if you don't want to troubleshoot the board for years you have to go ahead and check some things by yourself.

Do you have 3.3V at the power button by any chance?

Hi Sephir0th,

First of all, I checked, and yes, there is 3,3V at the power switch. As you mentioned, I searched for the gate connection of the SM3335 which receives 19V but does not turn on. I found it, it connects to a SOT-26 chip, but I have no idea what kind of chip it is. I have attached an image showing to which pin it connects.

There are two such chips with marking S2AN, the other S2AN is connected to the other SM3335 (which opens correctly), though the gate of that one is connected to a different PIN. I could further trace back the S2AN's to the charging IC.

Has anybody any idea on what this chip is?

Cheers,

sect-sin

[sect-sin]

Re: HP ProBook 650 G4 Blinking Amber Light

Hi all,

Today the new ISL9538 charging chip arrived from Mouser. I changed it, but unfortunately this did not help. The same blinking amber light prevails and it is driving me nuts. I think this board will be my nemesis, but I am definitely not about going to give up.
I will measure around randomly as Sepiroth has recommended, but would welcome any suggestions from you guys.

Cheers,

sect-sin

[dvbsmc]

Re: HP ProBook 650 G4 Blinking Amber Light

hi
do you have white light with amber light blinking or only amber light blink without white light? (on the power connector)

[sect-sin]

Re: HP ProBook 650 G4 Blinking Amber Light

Hi,

It was amber blinking light, no white light. I do not have the board anymore though.

Cheers,

sect-sin

[dvbsmc]

Re: HP ProBook 650 G4 Blinking Amber Light

thank you for your reply
i have 2 board elitebook and probook with the NPCX797HA1BX IO, the white light is on and amber light blink, and all voltage are good, i tested multi dumps but same thing, i think the bga IO must be reprogrammed or earased or replaced with a new one

[jverganio]

Re: HP ProBook 650 G4 Blinking Amber Light

Hi,

It was amber blinking light, no white light. I do not have the board anymore though.

Cheers,

sect-sin

Hi. Just a reference. Blinking orange light means a faulty/corrupted bios chip. In some cases bad solder joints on the bios chip.