Scoff
Senior Member
Last Activity: 03-01-2024, 02:54 PM
Joined: 07-22-2017
Location: South West
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Great, thank you very much! -
Schematic and Boardview - Sony Vaio DAORJ5MB8E1 REV: E MBX-148 Model PCG-9W1M / VGN-BX197XP
Hi, looking for the schematic and boardview if possible, for a Sony Vaio Laptop Model PCG-9W1M / VGN-BX197XP. The motherboard has references DAORJ5MB8E1 REV: E and MBX-148. Many thanks -
Re: HP Probook 470 G4 - Power and Charging Problem
OK thanks. I've removed the heatsink, increased the voltage to 2v and yes, the PCH area does start to get a little warm, up to around 39 degrees. The amps draw goes up to 1.80 Amps and fluctuates around there. No more hissing noise from the power supply this time.
Does this confirm game over for this particular board? If so that's a shame, being my first ever attempt, however I know a fair bit more about laptop boards in general and their workings, than I did when I started - so not a total loss. Perhaps a tricky board...Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
Thanks for explaining. OK so I set the max current on my power supply to 3A, and set the voltage to 1v. Ground lead to board ground, and positive lead onto the inductor PL37.
I can hear a slight 'hissing' form my power supply, and the current draw shows as 840mA - nothing seems to get hot though, checking various inductors by feel, as well as the heatsink above where the PCH is.
Are you able to help explain what this result means please? I do have some 'freeze spray' as well as some IPA if it helps to...Last edited by Scoff; 08-20-2023, 09:27 AM.Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
The mosfet testing was simply because it was something else I thought I could check in the meantime, while looking at the shorted 3.3V rails.
This is my first ever board repair attempt, so I am learning as I go, with practically no experience in this field. Which is why I am probably checking things that are a waste of time at this stage, as it's all a learning experience.
Regarding the voltage injection - is there a 'best' place to inject the voltage on this rail, or can it literally be anywhere on the 3.3V...Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
Just to clarify, as I didn't format my above post very clearly - results of testing the 2 mosfets near the inductor PL37:
[B]Mosfet PQ46[/B] is a 7752 GA7S2D N CHANNEL. The Drain of this mosfet connects to pin 1 of the PL37 inductor.
This mosfet reads 0.004v on diode mode between source and drain both ways (both polarities of test leads), and 1.6 Ohms across in resistance mode.
Also, on diode mode and resistance readings between gate pin and both the source and the drain (with lead polarities...Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
Thanks. Before I started with the troubleshooting I did a visual inspection of the board for any signs of burn damage - using a loupe - and could not see anything at all. I did not however take any readings of any of the inductors - is this normally a good first step in these cases, or as a matter of course? If so, what readings should I have been looking for when checking the inductors?
I will do some test with the 1v injection on the +3V rail like you suggest and report back. In the meantime, I have...Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
Resistance between any of the +3v caps and GND is 0.6 Ohms.
I forgot to mention that throughout this whole time, even with the new DC IN cable, I have not once had the LED on the DC IN Jack light up. Only the white LED on the power button yesterday. I believe the jack LED should light up amber when the battery is present and charging, but it should light up white to show the charger is present/providing voltage I believe.Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
Trying a different approach this morning. Removed the laptop charger and power button, and applied power at the charging port with my bench power supply - at the same entry point as the charger would provide the 19v so as not to introduce any voltage after any of the initial components on the board. There appears to be a minor fluctuation in amps, only 10mA comes and goes back to 0 every second or so, no change in the 19v. I'm not sure if this indicates that there isn't a short or not, but thought it might be worth ruling out any...Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
OK so new HP DC IN connector/jack arrived today, and fitted it straight away. Initially I thought great, I couldn't get the voltage to fluctuate/drop like I was getting with the old DC IN connector. Things seemed stable on the 19v power rail. I plugged the fan back in, and still getting the 19v power rail at PR237.
I plugged the power button back into the board so I could try power it up. The small white led on the power button board started flashing - in time with the clicking noise from the board, for 8 clicks/flashes,...Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
OK another update, with, what I think is good news.
Set up the meter again this morning, after changing nothing since yesterday. Plugged the charger in. Straight away, I'm getting the 19v power rail present on both mosfets, and around 25v on the gates!
The board hasn't moved position since testing yesterday. I kept the +ve meter probe on the PR237 leg as it's an easy test point to maintain, and gently started moving the DC IN port/cable around, like I was doing yesterday. After a few minutes of trying to...Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
Thanks, I'll need to invest in a microscope setup in order to progress and make things easier going forwards. I've been looking into various options recently so have an idea of what to look at for starting out.
The intermittent nature fits with the failure symptoms I was seeing prior to dismantling the laptop - where it would randomly just not turn on, the battery would deplete even with the charger plugged in, and some white charge port LED blinking occasionally, over the course of a couple of weeks, before finally...Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
Are you referring to the schematic that Sametbey posted in #22? If so, that must be from a different board model to mine, as I don't have a mosfet between the two DCin mosfets? The only reference to Q7 on my boardview is the one I mentioned relating to the power button, which is why I wanted to check if that's what you meant. Sorry if I'm missing something here. My power schematic is in post #23 which shows my board.Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
OK I will remove that mosfet and retest. Just to confirm, it's mosfet Q7 relating to the power button circuit here?
The dc in connector is genuine and original - I've owned the laptop from new and it hasn't been opened before. Also using the original HP charger - I've even just bought a new genuine HP charger from HP as a spare, which I'm currently using to test with. Centre pin is indeed positive.Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
Thank you for posting that, that gives me a good idea of what I should be expecting.
I've been examining the board view and tracing back the BQACP and BQACN, and I can now see what I believe is the CLR, as both ACP and ACN connect back to PR237
I can see PR237 on my board just below the 2nd MOSFET here:
so I plugged my charger in and tested the voltage on either side of PR237 - 19.6v?? I was expecting to see 0v, based on my readings at the BQ chip...Last edited by Scoff; 08-16-2023, 10:46 AM.Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
Hello, thank you. Are you able to explain where I would check this please? Looking up CLR shows Current Limiting Resistor, but I'm unsure how to identify this on the board? Looking at the board view, it shows BQACN connects directly to PR227, and there is continuity measured successfully between the two, and it shows BQACP connects directly to PR226, and again there is continuity between them....Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
OK thank you - I'll have to get my magnifying glass out for that one - no microscope as a newcomer to this sort of thing, and that resistor is tiny. I've got some heat resistance Kapton tape which I used for the MOSFET swap, so If I use some of that it should keep all the neighbouring resistors/caps in place and protected, and I have a small nozzle for the air gun. I'll report back once I've (hopefully) successfully removed that resistor...Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
With all components including the new MOSFET still on the board, and the charger plugged in, I've taken the following readings in case they are helpful:
BQACN = 0.001v
BQACP = 0.001v
BQCMSRC = 0.01v
BQACDRV = 0.014v
ADP_DET = 0.03v
BQACDET = 2.72v
BQIADP = 0.016v
BQVCC = 19.38v
REGN6V = 6.02v
BQLODRV = 0.000v
BQHIDRV = 0.129v
ADP_PRES = 0.000v
So the ACDRV is way too low, meaning the gate is not opening the MOSFET, as it requires...Last edited by Scoff; 08-15-2023, 10:24 AM.Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
It's taken a while to get the replacement mosfets, and also i've had some unexpected health issues. Anyway, today I have finally managed to replace the PQ26 mosfet. My first ever hot air removal and replacement of an item like this, after purchasing a hot air station. I think it went pretty well - I spent a lot of time watching videos on techniques etc. to build up confidence to tackle this.
Anyway, replaced the mosfet and upon testing, sadly I'm seeing exactly the same behaviour - only getting the 19v power rail...Leave a comment:
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Re: HP Probook 470 G4 - Power and Charging Problem
Will do - its going to take a while for the part to arrive. In the meantime, is it worth checking/confirming anything else, such as the adapter detection that you mention? Or is there no point until that mosfet is replaced?
p.s your username brought back happy gaming memories
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