Razer Blade 15 Advanced (2019): BIOS Programming gone wrong

[lenhuy2106]

Hi all,

my name is Banh and I regretfully fried something on the motherboard of my Razer laptop rz09-02886 when I tried to reflash the BIOS chip.

tl;dr: I'm looking for someone with the same laptop.


At first, it was only bricked because of a bluescreen during the bios update (windows), but after connecting the clip of a ch341a usb programmer to a (this is my big mistake i suppose) powered motherboard, it released a little bit of the smoke next to the clip. Now it won't even turn on the keyboard or fans.

The programming itself worked somehow, as I could read the chip and write it. But I already ordered 2 replacement chips of the same model.

Now, a resistor (R1) next to the chip Vcc input looks fried to me (as it faded in color) and I measure wobbling 1.144-1.160 MΩ resistance across it. The other three (R2-R4) on the right side look ok to me (constant 33Ω).

After I press the power button, I can measure 1.6V on the Vcc pin, coming from a via (α) - not enough for the chip to work I guess (Gigadevice GD25B127D).

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So what happened here?







I think, by connecting basically two power sources (Programmer 3.3V from the left and the original 3.3V rail from the right), I have blown resistor R1 with too much current.

My plan is now (as the last resort), to let someone replace resistor R1 and the bios chip, and maybe the capacitor C1 just to be safe.

(1) But what resistor value is it? I can't find any schematics, even with similar circuit: Most laptops I find online don't have a resistor in between. Could someone with the same laptop measure it in comparison?

(2) Why do I measure 1.6V, if the 3.3V power is open? Or am I completely wrong here in my amateur guess? Could just be more destroyed here, for example behind the via (α), and replacing resistor R1 only would not do it? I mean, even without the programmer, it would be two voltage sources in circuit here (1.6V and 3.3V).
What could possibly need those 1.6V? And why is it connected to the chip?

(3) When does the pain get easier?

__________

In the last days, I've learned very much what (not) to do. Even without fixing the laptop, I hope to prevent others from doing the same mistake, as many success stories online may lead to people (including myself) underestimating the process.

Things which can go wrong, will go wrong, so please take all safety measures you can think of before touching a motherboard circuit. Additionally, I was in a state of shock after the failed flashing and should have calmed down first. If you're unsure or don't feel well, don't do it.

Thanks for the help and much greetings from Germany!

[Sephir0th]

Re: Razer Blade 15 Advanced (2019): BIOS Programming gone wrong

I believe Your originally issue wasn't the Power from two sources, but a mistake in the orientation of the Clamp or similar. This is one of the reasons why using the Clamp isn't recommended.

However, it happened. So how can you be Sure These parts are Resistors? The Pics aren't clear enough for me to identify it for Sure. So the First Thing you have to do right now is to share a clear HD-Pic of this area, because of e.g. non-available Schematics.

I See two possibilities Here. If your 3.3V Power Supply is still working fine in General, you could be in the right direction. If it is a Resistor, it could be failed (partially) open. No Magic behind. But you have to do some additionally measurements to be Sure about this. Share the pic and we will see.

Greetings from Friesland

[mon2]

Re: Razer Blade 15 Advanced (2019): BIOS Programming gone wrong

Hi.

1) R1 is likely a low resistance (current limiting) resistor to +3v3. During this event, the component is damaged and caused the smoking you have observed.

2) Guessing the value will be 33 to 100 ohms. You can use a meter in resistance mode and try to measure what it is now but will be much higher in value.

3) Respectively, do not force this same event and you should be ok to bypass this resistor with a direct +3v3 feed. A short piece of wire across the resistor terminals is fine. Then +3v3 will power this flash IC and operate normally if the flash indeed contains the proper firmware.

4) If you really wish to replace this part, remove it and source the following:

33 ohms 5% 0402 SMD resistor
33 ohms 5% 0603 SMD resistor ( I think it is this size from the picture )
33 ohms 5% 0805 SMD resistor

One of the above will fit this same footprint and work like before.

As noted, it is not required and acts much like a one-time fuse.

[SMDFlea]

Re: Razer Blade 15 Advanced (2019): BIOS Programming gone wrong

In the last days, I've learned very much what (not) to do. Even without fixing the laptop, I hope to prevent others from doing the same mistake, as many success stories online may lead to people (including myself) underestimating the process.

Things which can go wrong, will go wrong, so please take all safety measures you can think of before touching a motherboard circuit. Additionally, I was in a state of shock after the failed flashing and should have calmed down first. If you're unsure or don't feel well, don't do it.

Wise words in hindsight .No schematic available for this board.

[Vesko356]

Re: Razer Blade 15 Advanced (2019): BIOS Programming gone wrong

You probably connected the clip incorrectly (upside down), and shortened the chip accordingly, so it is best to program the flash memory after it is desoldered out of the motherboard, in this scenario if you do something wrong you can burn the chip at most, but the way you did it, and without having experience, many problems can happen. Resistor R1 has burned out (for sure) and that's why it shows such a high resistance (and difference in voltage on both sides). It's probably 33 ohms one, and if you're lucky it may be the only damage. The voltage on both sides should be 3.3 V. So the first step is to replace it, then program the BIOS on a new chip outside the board, then solder the chip in place and test.

[mon2]

Re: Razer Blade 15 Advanced (2019): BIOS Programming gone wrong

You know, now that we are on this topic...how in the world can these (dirt) cheap CH431 bios programmers work? Perhaps I am mistaken but the design cannot be reliable.

Have seen many write ups / videos where others claim to just clamp the Pomona 8 pin (clones) onto their SOIC device and program away.

So let us review,

Case # 1 - the logic board is powered on and the logic board powers this target SOIC device. Fine. How in the world does the SPI flash bus master release these SAME target lines so that this external CH431 programmer can assert its logic levels?

Solution: You have to apply a #RESET = LOW to release the SPI BUS master on the logic board = hi-z the lines and only then can this external USB widget work.

Case # 2 - seen this too many times. The USB widget powers this target SOIC device. Really? So now, a USB device (that is max 500mA according to USB spec) is powering the +3v3 rail of the logic board??

We are designing a programmer and see many flaws or are mistaken. In our design, applying push-pull level translators so we can intermingle with the logic levels and also another similar device for the i2C bus style of memory.

Welcome feedback from other owners of this tool. The above issue raised by OP was expected.

[lenhuy2106]

Re: Razer Blade 15 Advanced (2019): BIOS Programming gone wrong

So the First Thing you have to do right now is to share a clear HD-Pic of this area

I took one picture with a better camera. The damage is very noticable e.g. the black resistor(?) color fainted translucently:

So how can you be Sure These parts are Resistors

I admit, I'm not particularly sure that it's a resistor - I gathered, that there are three lines nearby with a resistor each. What other component could make sense instead?

If your 3.3V Power Supply is still working fine

As far as I can measure, yes. All my hopes rest on that.

it could be failed (partially) open

That makes sense. Do resistors fail partially, so that it halves the voltage? And what resistance would I typically measure in that case?

Thank you Sephir0th and greetings back

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You can use a meter in resistance mode and try to measure what it is now

Yes, I measure between 1.144-1.160 MΩ now.

it is not required and acts much like a one-time fuse.

Thanks. Any reason why it's 33ohm in particular, and not e.g. 0ohm instead? And how confident is this guess?
I still hope for someone with the same mainboard to give me the 100% safety, but if not, I would eventually replace it with your infos in mind then.

Have seen many write ups / videos where others claim to just clamp the Pomona 8 pin (clones) onto their SOIC device and program away.

That's the honeypot I fell to. Now, it did program successfully (according to the flash software), so I can't tell you more except the process in my case failed due to my own neglect.

Thank you mon2.

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it is best to program the flash memory after it is desoldered out of the motherboard

Yes. That would be my way to go anytime the problem reoccurs. It's a shame I needed the hands-on experience to know that.

Thank you Vesko356.

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Thanks again for all your valueable insight.