Troubleshooting Razer Blade 15 DA560

[chickenhawk88]

I started troubleshooting this Razer Blade 15 laptop DA560 motgerboard a while back, due to some shorted 19v, 5v, 1v power rails. I fixed some of components and think 19v rail is good, 5v rail is good, 3v is better but not all way i think, and 1v is still bad. At this point the diode reading on these rails are 19v - 0.032v , 5v - 0.167v, 3 - 0.63v and 1v - 0.005v .

When the rails when down, I went down different rabbit holes and seeing chips getting pretty warm on thermal but not blazing hot. Yet there were not any caps or any small components getting blazing hot. Example is EC chip, when installed it brought diode reading from 0.063v to 0.005v with .500 amp draw on 3.3v 1a bench power supply. So im asking is the EC chip getting warm cause its connecting part of shorted circuit within chip or just normal ops cause it got volt applied to it?

One other question. When i applied bench power 3.2v or 5.2v 1.5a, to the fuse where the power comes in, it takes bench power down to 2.91v with max 1.5a draw. And the mosfet after the first 2 in rush mosfet is showing warm on cam. I swapped the warm mosfet with new one with same result. So im thinking its doing its job shoving volt to ground see that there is fault in system ? Is this correct?

Im still kinda new to laptop motherboard repairs and trying to get this.

[Sephir0th]

Well, you are dealing with multiple shorted components at least on a)the Main Power Rail (sounds like High-Side Short), b)the 1.05V (likely bad PCH) and c)the 3V LDO (obviiusly the EC).

Basically each component which significantly changes the temperature while voltage injection in combination with unusual current draw is fried. In case of a warm Mosfet it might be different and the actual issue is located on the load side.

3V and 5V looks okay, but better to have (all!) values in Ohms mode, sinde Diode readings are almost useless and naturally hard to compare depending on what multimeter was used.

All questions answered?

PS: How was it possible to damage the board so massively in so many places at the same time?

Regards

[chickenhawk88]

Well, you are dealing with multiple shorted components at least on a)the Main Power Rail (sounds like High-Side Short), b)the 1.05V (likely bad PCH) and c)the 3V LDO (obviiusly the EC).

Basically each component which significantly changes the temperature while voltage injection in combination with unusual current draw is fried. In case of a warm Mosfet it might be different and the actual issue is located on the load side.

3V and 5V looks okay, but better to have (all!) values in Ohms mode, sinde Diode readings are almost useless and naturally hard to compare depending on what multimeter was used.

All questions answered?

PS: How was it possible to damage the board so massively in so many places at the same time?

Regards

I was trying to fix a bad memory slot that was shorted from corrosion on memory module slot. I changed out the tant cap, mosfet for 3.3v rail, hooked up everything including the laptop adapter. Then i heard a loud pop and smoke. Thats when i started down the rabbit holes. The current diode reading is with the EC chip out of the board.

I thought the diode mode would be better as it takes in account the different components/diodes. Like diode it will read one way and not other due to polarity. I am using Fluke 101 meter.Here are ohm reading for PCH. The resistance between the meter probe is .4 ohms. When i put black probe on pos of cap and red probe on inductor, i get 59.2 ohms, that would indicate the driver is ok and pch didnt get damage?

19v rail - 59.4 ohm
5v rail - 951 ohm
3v rail - 119.4 ohms
1v rail - 9.1 ohms



Thanks for your reply. I think really f up the board.

[Sephir0th]

With the Ohms reading we figured the worse situation of the 3V and even about the 5V I am not really convinced it being healthy. Although it proves what i assumed, you should repeat this measurement with Black probe to GND and Red probe to rail in question to rule out any false positive reading.

Either way, you have a lot to do and to find out what components causes all these low values.

[chickenhawk88]

Ok. So with thermal cam, i found 3 ic chip for the usb that was causing the short on 1v rail and i took them off.

Ec chip is still off the board.


Measuring at the +cap and gnd


Now the values for with black probe on gnd.
19v - 17k ohm and climbs slow
5v - 8k ohm and climbs slow
3v - 124.8 ohm
1v - 280 ohm

With red probe on gnd
19v - o.l.
5v - o.l
3v- 124 ohm
1v - 348 ohm

With red probe on gnd . Diode reading
19v - .362v
5v- .165v
3v - .065v
1v - .171v

[Sephir0th]

19V is good, 5V is good, 1V is good now too, although it sounds almost too high and although from the picture it looks more like 1.2V for the RAM (Where is the PCH located?). At the 3V you have still a partial short to GND which you need to figure out.

[chickenhawk88]

19V is good, 5V is good, 1V is good now too, although it sounds almost too high and although from the picture it looks more like 1.2V for the RAM (Where is the PCH located?). At the 3V you have still a partial short to GND which you need to figure out.

Thanks for reply, the PCH is to the left on the other side of memory module where I took the readings for the power rails. I checked the connections on the board for the usb chips and the VDD33 is 11.5ohms which is low.

Here is link to picture of motherboard.

https://www.badcaps.net/special/albu...60-motherboard

[chickenhawk88]

19V is good, 5V is good, 1V is good now too, although it sounds almost too high and although from the picture it looks more like 1.2V for the RAM (Where is the PCH located?). At the 3V you have still a partial short to GND which you need to figure out.

Here is side with the PCH and cpu and gpu

[chickenhawk88]

For some reason I can't upload a higher res /larger pic to the post.

[Sephir0th]

The actual +1.05V supply is more likely located here.

[chickenhawk88]

I do believe i was getting 19v there when the laptop was working with one bad memory module slot. I measure what kind of volt on the other spots where i got my readings and that where i got the 19v , 5v , 3v and 1v . But yeah i understand why thats the power supply for pch vcore , like all the caps by the gpu and cpu v cores.

I did some more digging and a few more chips were bad - Parade PS8461E (diplay) , P13DPX (display mux switch). I order these chips and will get here in few weeks from China.

Resistance read red on gnd

19v - 3.4k and climb slow
5v - 990 ohm
3v - 310 ohm
1v - 362 ohm

Cap by pch - 3.4k and climb slow

[chickenhawk88]

I tried looking at your YouTube link and dosent work, what happened ? Thanks again, i hope i can get this working somehow.

[Sephir0th]

I tried looking at your YouTube link and dosent work, what happened ? Thanks again, i hope i can get this working somehow.

Thanks for heads-up. Link is fixed. Unfortunately 310 Ohms is still to low for 3VALW.

[chickenhawk88]

Thanks for heads-up. Link is fixed. Unfortunately 310 Ohms is still to low for 3VALW.

OK. I'll keep looking around the board while I wait for the parts. Link is good now and subscribed to your channel.

[chickenhawk88]

Thanks for heads-up. Link is fixed. Unfortunately 310 Ohms is still to low for 3VALW.

Quick question. Is there way to check if the southbridge chip/PCH is gone, like checking the caps on the chip die itself? I have replaced all the components that I took off that was bad and now when I put 5v 1amp limit voltage on the input fuse where the 19v comes in from ac adapter it takes the full 1 amp draw. The dual mosfet with the arrow in the pic is one that is causing the amp draw, but when I removed it and applied the volt to individual pads it dose not take 1amp draw/ barely any draw. Its not the mosfet as I put a new part and got same result.

[Sephir0th]

This is likely not the Main Power Rail in what you're injecting, but the Dual-Mosfet related battery charging rail. So in worst case, you are injecting into the GND plane. Surprise, surprise, the board will take the whole 1 Amp then.

The DC-IN Mosfets are located on the right. The current sense resistor for main power rail is on the back. Next time you use your multimeter to proof please before blindly injecting somewhere what you might regret afterwards.

Either way, the observation after you remlved the Dual-Mosfet makes no sense, since at least the GND pads would take the current. So i assume you have additionally issues to get proper GND for your PSU.

Also I think I've spottrd that you lost already a important resistor at the bottom of this Mosfet.

[chickenhawk88]

This is likely not the Main Power Rail in what you're injecting, but the Dual-Mosfet related battery charging rail. So in worst case, you are injecting into the GND plane. Surprise, surprise, the board will take the whole 1 Amp then.

The DC-IN Mosfets are located on the right. The current sense resistor for main power rail is on the back. Next time you use your multimeter to proof please before blindly injecting somewhere what you might regret afterwards.

Either way, the observation after you remlved the Dual-Mosfet makes no sense, since at least the GND pads would take the current. So i assume you have additionally issues to get proper GND for your PSU.

Also I think I've spottrd that you lost already a important resistor at the bottom of this Mosfet.

Is the way the dual mosfet work is if there was something wrong with the circuit that it would sink it to ground thus protecting the circuit? So when I remove the mosfet and I checked each leg and none had a direct short to ground. I checked my earlier pictures , although kinda hard to see I don't see the missing resistor.

What do you mean proper GND for my PSU ? My bench power supply is plugged into a power strip, and that is into outlet. None of the ground pins are broken off. I'll look around to see if anyone has picture of the motherboard area.

[Sephir0th]

You don't need to be rocket scientist to understand that the bottom Pads are the GND plane, so no, it is not the way how the Mosfet behaves in your case. You simply did not connect the GND probe of the PSU properly. A small but serious mistake, especially when you start forming conclusions on this base.

From my understanding there is clearly a small component missing (circled). However we will ignore it for now since you have so much to do, that we will need months to get some sort of final diagnose anyway.

instead and since you're still running in circles caused by doing the wrong things in the wrong sections strongly suggest to start over, especially with the Main power rail and try to bring it backnto life.

But this requires that you take a look to the Charging controller now and in best case, measure voltages and resistance to GND of all pins.