DAX1BDMB6F0 Power Issue

[Pierre-Yves]

Hello,

I have an HP Pavillion notebook laptop model 15 ab253ca.

I won't turn on. The power supply unit is fine. I changed the power button and USB card to which the power button is plugged in with no results.

The motherboard is a DAX1BDMB6F0 and connecting the power supply has intermittent results. The charging lignt comes on sometimes moreoften when the board rests for a while (1/2 hr to an hour). On rare occasions when I press the power button and the charging light is on, the computer comes on, but more often the charging light goes off and nothing happens. I need to unplug the power supply and let it rest for a while for the charging light to come back on.

I took voltmeter readings and there is 19.9V at the red wire coming in the board. There is 19.9V at the first mosfet, on both sides (where power comes in and goes out). The second mosfet comes in at 19.9V but leaves at 0.19V when the charging light is not on and at 0.87V when it is on.

Really would appreciate to connect with anyone who has some knowledge about these laptop power circuits.

[kotnatan]

Re: DAX1BDMB6F0 Power Issue

http://**************/load/noutbuki/.../307-1-0-56662

http://**************/load/noutbuki/.../307-1-0-56664

[BlueMidnight]

Re: DAX1BDMB6F0 Power Issue

There is no free schematic available for this board that I can find. But that may not be necessary.

First, we need to know the voltage on all pins input FETs. You mentioned the source and drain pin voltages, but we still need to know the gate pin voltages.

Second, a clear picture of that area of the board (front and back) would be helpful. The FETs are on one side and the charger IC is on the other. At the very least, the part numbers of all those would help.

[Pierre-Yves]

Re: DAX1BDMB6F0 Power Issue

Thanks for the response. I have uploaded three pictures of the board, one of the entire board, the other two of the area of interest (front and back). If you zoom in a bit, you can read off the part #s (One picture is here, the other two are in the next post.).

https://www.badcaps.net/forum/attach...1&d=1530143848

The voltage on the first FET after the red power wire coming into the board is 19.7 on all 4 pins. On the other side of that FET it is 15.5 on the first pin and 19.7 on the other 3 pins. On the next FET it is 19.7 on all 4 pins and on the other side, 0.7 on all four pins. On the third FET, it is 0.7 on all four pins and 0.00 on the other side on all four pins.

There is a bigger FET (I gather it is the "gate" you referred to) that has 24.6 on one pin and 19.7 on the other three and on the other side it has 19.7 on all four pins.

If I turn the board there is a FET that has 19.7 on all four pins and on the other side 0.7 on all four pins.

[Pierre-Yves]

Re: DAX1BDMB6F0 Power Issue

The previous pictures did not seem to upload correctly. Try these.

https://www.badcaps.net/forum/attach...1&d=1530145060


https://www.badcaps.net/forum/attach...1&d=1530145252

[BlueMidnight]

Re: DAX1BDMB6F0 Power Issue

There are a couple ways to get pictures to show up in your message. The best is to just use the "Manage Attachments" link and upload the pictures there. They will show up at the bottom of your post without you needing to add anything else to the body of your message.

For the pin voltages, it's best to list pin numbers they were measured on. For help with pin numbering, see here.

The connections to a FET are named "source", "drain", and "gate". The FET is basically a switch that connects the source and drain only if the voltage on the gate is within a certain range. That range is determined by the type of FET that it is. For more about MOSFETs, see here.

The 2 input MOSFETs on your board are indicated in the first attached picture. It sounds like you measured the small FET on the left, then the 2 small ones on the right, and finally the large one in the middle. Therefore, you seem to have 19.7V on all pins of the first input FET (red), except for 15.5V on pin 4. And 19.7V on all pins of the second input FET (yellow), except for 24.6V on pin 4. Am I understanding you correctly?

If that is correct, then 19V is passing onto the main power rail like it is supposed to. So, the next thing to try is to measure the voltages on all the grey coils. The coils are indicated in the second attached picture. I gave them names so they are easy to refer to. Measurements should be taken with the heatsink/fan, memory, and 3V coin cell battery installed. Each coil has 2 pins, but it doesn't matter which pin you measure.

[Pierre-Yves]

Re: DAX1BDMB6F0 Power Issue

Thank you, will do this tonight once back from work.

Pierre-Yves

[Pierre-Yves]

Re: DAX1BDMB6F0 Power Issue

Thanks again for all the information, I see that you have taken time to explain this so it is appreciated.

I had a mishap happen. The center pin in the power supply connector broke just now and of course I'm stuck...

I took the measurements of the grey coils before the pin broke but please note that the charging light was not on. Please note as well that the fan was not turning but was plugged to the board and the battery was in its place on the board.

A= 0.19v
B= 0
C= 0
D= 0
E= 1.02v
F= 5.07v
G= 3.33v

About your question, you are correct, and yes it is pin 4 with 24v. I took measurements on the pin that gave me 15.5v and made a better connection and that pin went up to 19v

I will try to find another power supply as soon as possible

[ggallarde]

Re: DAX1BDMB6F0 Power Issue

try this

[BlueMidnight]

Re: DAX1BDMB6F0 Power Issue

Thank you to ggallarde. I can now attach real names to everything without wondering how different the X1A schematic is from the X1B.

A = PL8 = Battery charge voltage (+BATCHG)
B = PL16 = CPU graphics (+VCCGT)
C = PL14 = CPU core (+VCC_CORE)
D = PL12 = CPU system agent (+VCCSA)
E = PL13 = Deep Suspend rail (+1.0V_DEEP_SUS)
F = PL11 = 5V rail (+5VS5)
G = PL17 = 3V rail (+3VS5)

And one I didn't label, way over next to the memory slots, is PL26 for the memory power rail (+1.35VSUS).

So it's actually getting pretty far. It has the 3V and 5V rails powered.

Next, find the EC chip. It's on the back of the board and has "iTE" written on it. See the attached picture.

- Measure the voltage on pin 119 (RSMRST#).
- With the power button board connected, measure pin 107 (NBSWON1#). There should be 3V. Press the power button. The voltage should drop to 0V. Release the power button and the voltage should rise back to 3V.

Count the pins carefully. And be very careful not to short out adjacent pins. It is safest to just look at where the traces go from those pins and measure the voltage at a nearby component or test pad.

[Pierre-Yves]

Re: DAX1BDMB6F0 Power Issue

Hello, & yes, nice of ggallarde to have provided the schematic for the X1B - Thanks!

Did the measures (with the center pin gone in the power supply connector, but that did not seem to make a difference).

Pin 119 on the EC reads 0v
Pin 107 reads 3.16v and when I press the power button, it goes down to 0.25V

and by the way, the memory power grey coil read 0v.

[BlueMidnight]

Re: DAX1BDMB6F0 Power Issue

Okay, so everything you've measured is working right up until RSMRST#, which is supposed to go up to 3V.

The last few pages in the schematic describe the power sequence. And if we work backwards from the RSMRST# step, we can see if there is anything else missing. There are 3 outputs we haven't tested yet.

Measure voltage on:
- iTE chip pin 89 (SLP_SUS_ON)... refer to previous post for pin numbering
- Firmware chip pin 8 (+3V_DEEP_SUS)... see attachment
- 1.8V regulator output inductor (+1.8V_DEEP_SUS)... see attachment

[Pierre-Yves]

Re: DAX1BDMB6F0 Power Issue

Hello,

ITE chip pin 89 = 3.02V
Firmware chip pin 8 = 3.33V
Regulator output inductor = 1.78V

Please note the following:
- When I hook the power supply to the card in the morning, the charging light comes on and if I press the power button, I get power. I can turn off and on the power from the power button and everthing seems to work. When I remove the power supply connector and hook it back on, that's when more often than not the charging light does not come back on and pressing the power button does nothing. Rest assured though that when I took all the readings above, the charging light was not on.

[BlueMidnight]

Re: DAX1BDMB6F0 Power Issue

Unfortunately, those readings are perfectly normal..

Next, check:
- iTE chip pin 87 (DSWROK_EC)... make sure this is 3V
- Just to confirm the sequence on this particular board (since some boards like to switch this up and the diagram is ambiguous).. is there any change in RSMRST# when you press the power button?
- Likewise, are there any changes in iTE chip pin 21 (DNBSWON#) as you press and release the power button?

If DSWROK_EC is 3V and there are no changes when you check the other 2 things, then there may be something going wrong with the EC (iTE chip) itself, a solder joint, etc.

[Pierre-Yves]

Re: DAX1BDMB6F0 Power Issue

Hello BlueMidnight,

After running the ITE, Firmware and regulator output inductor tests, I noticed that the charging light came on. I turned the power button on and it
it came on. Unplugging the power supply, plugging it back in resulted in the charging light staying on and being able to press the power button on and off and it worked. So I rebuit the laptop and turned it on, and it worked. I turned it off and could not turn it back on and the power button would blink when I pressed it. If I wait 15-30 secs, press the power button, the laptop comes on. I'm not too happy about that because it sounds like an intermittant problem and as you say, could be a solder joint.

I would have like to have done your last suggested checks but by the time I would take the readings, everything would be normal again. This is discouraging as I was looking forward to finding the issue with your assistance.

By Friday the 6th of July, I should get the new power supply I ordered. Apparently the center pin (smart pin) that broke off has a function and according to a post, when broken, there are issues powering up HP laptops so I would like to eliminate that possibility.

I will keep you posted. I put you down as a contact but I'm not sure how that works exactly.

[piernov]

Re: DAX1BDMB6F0 Power Issue

The center pin is needed for an HP laptop to boot.

[BlueMidnight]

Re: DAX1BDMB6F0 Power Issue

Just reply here and I'll get a notification.

It will be interesting to see if anything changes with the new AC adapter. At the very least, the ID pin (or Smart Pin as HP likes to call it) needs to be there to enable simultaneous charging of the battery while the notebook is powered on.

However, it is highly doubtful that pin alone is responsible for your current troubles unless enough of the pin remains to make intermittent contact. Whatever logic is programmed in to the firmware on this particular board, I am certain a random number generator is not involved. And yours seems/seemed perfectly happy to power up sporadically.

[Stevie2001]

Re: DAX1BDMB6F0 Power Issue

Do this if you do you will save shit load time.
Since it is power issue spend time taking notes down like this.

Your motherboard has power or charging ic find the main power if its hard then go through it one by one checking the number on ic and google it.

Your looking for power controller ic google it by looking at the numbers on top of ic and check the datasheet for each ic and the pins and here is what you do.

Looking for short.
Check datasheet which pin on ic is gnd and then ignore that pin and set multi-meter to beep mode and connect black to gnd and swipe red probe on all pins and se if any pins beep acvording to datasheet ignoring the gnd pin on ic and if non beep then that ic is good.

Some ic may not have gnd pin but carry out the same thing.
Do same on all ic you se on motherboard that has to do with power mate.

Some may reply to my post giving negetive replies.
I done this and it works give it a try its FREE dont cost nothing.

Make sure to inplug before test

[piernov]

Re: DAX1BDMB6F0 Power Issue

HP usually requires the center pin. Can't say for sure on all machines but I've seen multiple issues caused by center pin, so first use a known good AC adapter. Also some cheap Chinese ones will have a fucked up center pin level so use an original one preferably. AC adapter not recognized correctly may or may not generate a pattern (3 blinks maybe? not sure) on the power jack LED.

On the other hand Dell doesn't require center pin to boot, but it will not charge the battery and CPU may be throttled, and it will display a warning while POSTing.

[BlueMidnight]

Re: DAX1BDMB6F0 Power Issue

Yeah it's 3 blinks at the jack if it does the blinking pattern. But it will boot from a good battery and just refuse to charge it (URL="http://i.imgur.com/rqQrPVq.png"]with complaints[/URL]).

An adapter that is poorly manufactured or has a bent/cracked center pin can cause inconsistent behavior. An adapter with a totally missing center pin ought to be consistent in behavior. It kind of defeats the purpose of the feature if it decides to boot off an unknown adapter half the time anyway heh. Though.. stranger things have happened..