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paulo66 replied to ME Firmware Cleaning Guide

in BIOS Requests ONLY!

10-12-2021, 03:48 PM
Re: ME Firmware Cleaning Guide

Nah, I´ve just tried pressing the power button for 15 seconds and the unit has come to life everytime. So far.
It's funny how the tube is so infested with 'tutorials' that only offer this solution, you don´t want to know about it anymore. But hey it´s working.
Thanks for taking the time to reply

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paulo66 replied to ME Firmware Cleaning Guide

in BIOS Requests ONLY!

10-12-2021, 02:43 AM
Re: ME Firmware Cleaning Guide

The original chip was bad, so no backup. I then burned a new one though can't remember where I got the file. The issue persists, but it´s good to know that updating the BIOS using the HP utility rules out the ME region as a probable cause. I'll have to look elsewhere.

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paulo66 replied to ME Firmware Cleaning Guide

in BIOS Requests ONLY!

10-11-2021, 04:14 PM
Re: ME Firmware Cleaning Guide

Thanks.

I already flashed the BIOS (same version as before) as provided by HP, but my laptop still boots randomly and occasionally turns off. The sp96831.exe contains 4 .bin and 4 .s12 files. I have no idea why, nor if the HP flasher chooses the suitable version automatically.

I tried some of the files in the original post, but I don´t really know what I´m doing......

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paulo66 replied to ME Firmware Cleaning Guide

in BIOS Requests ONLY!

10-11-2021, 03:51 PM
Re: ME Firmware Cleaning Guide

Does anyone know if the BIOS updates provided by HP Support come already clean?

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paulo66 replied to Asus N61VN rev. 2.1 boardview and/or schematics, please

in Schematic Requests ONLY!

03-26-2021, 11:46 AM
Re: Asus N61VN rev. 2.1 boardview and/or schematics, please

Not necessary anymore.

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paulo66 started a topic Asus N61VN rev. 2.1 boardview and/or schematics, please

in Schematic Requests ONLY!

03-24-2021, 04:47 PM
Asus N61VN rev. 2.1 boardview and/or schematics, please

Strange short between charging port and pin 4 of second mosfet. Can't trace it

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paulo66 replied to Are some components spot-welded to the MBs?

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-24-2021, 06:13 AM
Re: Are some components spot-welded to the MBs?

Thank you for the thorough reply. I liked the encyclopedical style.
Those questions have all been addressed throughout the thread by various posters and some have been rebated.
Note on the second picture the mosfet was replaced using the st862d and the shielding was still in place.
I've since done some rework without any shielding and I'll eat crow after insisting with another poster nearby pieces would fly off the board with the new station none has so far.

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paulo66 replied to Are some components spot-welded to the MBs?

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-23-2021, 12:40 PM
Re: Are some components spot-welded to the MBs?

The mosfet in the ot took another 30 seconds, or less. This machine rules. I'm "blown" away. Sorry ...

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paulo66 replied to Are some components spot-welded to the MBs?

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-23-2021, 12:26 PM
Re: Are some components spot-welded to the MBs?

That is what's left from the coil that the 858 couldn't remove. The "casing" which is actually all ferrite was eaten by the tweezers.

With the 862 it took only 30 seconds. I´m amazed.

Now, how do I get the nozzle off the handle? I think it's stuck!...

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paulo66 replied to Toshiba C50D-A133 - one problem after another

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-22-2021, 12:20 PM
Re: Toshiba C50D-A133 - one problem after another

I can´t believe this s**t happened again.

Just got another non-working motherboard, this time identical to the first. Charge port ferrite inductor was open, shunted it with a wire. A decoupling capacitor from the B+ to the CPU was shorted, removed it. Second MOSFET was open, shunted with a wire. Managed to power the unit up, with power LED on, fan spinning, all voltages present. Powered it down, plugged the display, no image. No LED either. Buck converter burned my fingers

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paulo66 replied to HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-19-2021, 04:10 PM
Re: HP Pavilion Laptop Motherboard Not Starting Up

Is there any continuity between kbc vdd and the +3v_rtc?

Because there is only one point in the schematic where it´s clear the connection between +3vpcu and +3v. Page 7. Locate D11 and D12. D11 prevents the coin cell current from reaching the ldo output of pu7, or the low resistance would drain the battery quickly. D12 on the other hand prevents pu7 from charging up the coin cell. Which isn't rechargeable.

They´re Schottkys. So all this is at the cost of D11 voltage drop of 0.3V. Hence +3V < 3.3V....

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paulo66 replied to HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-19-2021, 10:04 AM
Re: HP Pavilion Laptop Motherboard Not Starting Up

Last post in a row.

What about injecting 3.3 at r406 (opposite side of the kbc) or at the kbc itself (pin 11)?

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paulo66 replied to HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-19-2021, 09:54 AM
Re: HP Pavilion Laptop Motherboard Not Starting Up

One thing I forgot to mention: maybe your laconic approach is the type professionals want to read. Practical advice for a quick fix. No time for theory because of deadlines. No customer likes to wait. I respect that and maybe this forum is not the right place for hobbyists that like to zoom in.

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paulo66 replied to HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-19-2021, 09:36 AM
Re: HP Pavilion Laptop Motherboard Not Starting Up

It´s not a matter of being convinced or not. It´s just me trying to learn with the limited info available. Instead of just, you know, blindly following orders.
I´m sure you know the old saying "Give a man a fish..." Maybe your knowledge is only empirical, and I respect that. Or maybe that´s your thing, in which case I´m out....

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paulo66 replied to HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-19-2021, 09:13 AM
Re: HP Pavilion Laptop Motherboard Not Starting Up

Second and third paragraphs in post #12. No answers yet, just speculating. Still trying to learn how the motherboards work at component level.

I´ve had a similar case with 1.8v ax pin 8 of the bios chip. Didn´t read the kbc vin because I didnt know what to look for. But the vreg was 3.3. The bios was defective.

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paulo66 replied to HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-19-2021, 03:05 AM
Re: HP Pavilion Laptop Motherboard Not Starting Up

Is it safe to power up the unit without the kbc in place? On another thread I was told not to do that.

Ldo is vreg, right? If there's 3.3 present at pin 8 of pu7, and there's less than 2v at kbc, then there is some kind of isolation. Otherwise the voltage loss would come all the way down to pu7.
The fact that there is a 0.3v difference under normal conditions seems to point to a semiconductor drop.

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paulo66 replied to Slow writing programmer

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-18-2021, 02:46 PM
Re: Slow writing programmer

Ummm nope. Mine is the CS. But whatever, mine serves me well. Autoelectric did a good job.

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paulo66 replied to Slow writing programmer

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-18-2021, 02:33 PM
Re: Slow writing programmer

I´ve been using a TL866II for years to update the firmware of vintage synths or simply burn the old quartz window EPROMs with the same code, since their information is held by tiny capacitors which, after a few decades of reliable service, eventually get discharged.

It´s also good for testing CMOS logic chips.

Usually the only error with these happens when a new EPROM with a different sufix or from a different manufacturer replaces the original. To get around with it we simply disable the Verify function, or change the...

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paulo66 replied to HP Pavilion Laptop Motherboard Not Starting Up DA0R53MB6E1

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-18-2021, 01:20 PM
Re: HP Pavilion Laptop Motherboard Not Starting Up

There is a boardview file for this board.

[url]https://drive.google.com/file/d/1v4Pac3k6QadBYgNa3hdKxZ0UsNkK88Xa/view[/url]

This one in particular offers limited info so you still need the schematics for parts names and values. For instance, R406 is zero ohms, and it leads to 116 other components.

The KBC_P+3V must be derived from the +3.3v linear output of pu7. Which reads normal, right? One of those 116 parts must be sinking a bit of current.

What is the voltage across...

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paulo66 replied to Are some components spot-welded to the MBs?

in Troubleshooting Laptops, Tablets, and Mobile Devices

03-16-2021, 03:53 PM
Re: Are some components spot-welded to the MBs?

Thanks. Yes, part of the problem is the leadfree solder. I will try that with the mosfet shown in the first post. Which btw is the high one. It sits on the B+ track. The low mosfet is the one with ground plane underneath, so it will be even more difficult to remove.

I´m trying to remove them to track down a strange short circuit in the +19V path. It´s showing unusual readings. The voltage fluctuates cyclically as if some auto-protect mode keeps turning on and off...

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