Lenovo V330-15IKB - no picture

[YellowJacket]

Greetings badcaps community,

I would ask for little help with diagnosing Lenovo V330-15IKB, which I got as dead - after pressing the power button there was no reaction, just dead.

Model: V330-15IKB
Board number: LV315KB ; 17807-3 ; 448.0DC04.0031
Serial number: R90Q6BW3
(Schematic, boardview and resistances/voltages attached)

When I got it, battery had 0V, so I am diagnosing it without battery, with original lenovo charger. After some searching, I managed to make it run by reflashing the bios - but I have no picture ( even on attached monitor ) and no reaction to caps lock/num lock on external keyboard. On the laptop keyboard, there is capslock diode ON all the time. I tried many bios dumps, but the result was still the same. I am using this one at the moment --> https://www.badcaps.net/forum/showth...p+%28Lenovo%29 ( post #2 ).
Next, I tried to disable onboard RAM, by moving resistor R2010 to position R2009 - datasheet page 20, and this post helped me too --> https://www.badcaps.net/forum/showthread.php?t=100557 ( post #8 ). Still same result.

So I am out of ideas, and I would like to ask you guys, with more experience, how can I figure out, why it is stuck? Is there anything, I can try? Or it is dead cpu/pch ( bad solder joint maybe )? If it helps, I was able to measure these signals:
PLTRST# = 3.5V
DDR4_DRAMRST# = 1.2V
THERMTRIP# = 1V
There is no voltage at one coil ( PL4803 ), with power rail 1V_VCCGT, I believe, its not necessary, since its igpu, right?

Thank you very much for any hint.

MOD Edit:
Link to schematic - https://www.badcaps.net/forum/showthread.php?t=88250
Reminder: rules and organization of this section - https://www.badcaps.net/forum/showthread.php?t=117483
.

[reformatt]

Re: Lenovo V330-15IKB - no picture

Check input current with and without RAM. Check RAM connector pins are all solid to the PCB and free of debris etc.

[YellowJacket]

Re: Lenovo V330-15IKB - no picture

CORRECTION in the picture: the coil for main power rail is not 4.5V, but 9.6V ( 4.5V was before flashing bios, when the laptop was dead ).

Still, is it enough to be 9.6V at 19V_DCBATOUT power rail? I mean yeah, if there is battery connected without charger, there will be only ~8.7V here, but still, I am not sure ( datasheet, page 44 ).


@reformatt - sadly, I am not able to measure current. I was trying to do it with an oscilloscope, across current sensing resistor PR4401, but I can't read any value. RAM connector is indeed clean and intact.

[reformatt]

Re: Lenovo V330-15IKB - no picture

Charger in this is a buck-boost converter so you won't see 19V there, it will be roughly the max voltage of the battery. You have Vcore on the CPU, so this proves that all the supplies are ok. CPU should at least be warm even if it's not booting.

It's an Intel platform so your donor BIOS needs to have a clean ME region. I would suggest you upload your original BIOS to the BIOS group for repair and try that first, rather than using random donors.

Monitoring input current during power on gives you an indication as to whether the CPU is actually running (as you will see the current varying up and down as it's begins to boot). This is why you need to try that with and without RAM to at least see if the system is recognising the RAM.

[YellowJacket]

Re: Lenovo V330-15IKB - no picture

CPU is warm - the longer is board running, the more is temperature rising ( until some point of course ).

I would suggest you upload your original BIOS to the BIOS group for repair and try that first, rather than using random donors.

Sadly, I was unable to read original bios ( either I did something wrong, or bios chip was damaged ), so I have no original dump. I wrote here before - https://www.badcaps.net/forum/showth...67#post1281467 ( post 56# ), that's why I used that bios dump. I don't know what else I can try without original dump.

About current monitoring - I fully understand, and I always make this procedure during diagnosing, but not in lenovo case, where is middle pin ( rectangle charger connector ). Do you suggest me to inject 20V into the charger port? Would it work without using middle pin?

Thank you for your suggestions, appreciate it.

[YellowJacket]

Re: Lenovo V330-15IKB - no picture

Ok, I tried to inject 20V, during start with RAM current fluctuated between 370 - 440 mA, then it stayed at 380 mA.

Without RAM it stayed at 300 mA.

Note, onboard ram is disabled, as I mentioned before.

[rddube]

Re: Lenovo V330-15IKB - no picture

Could you post a picture without heat sink please.

[YellowJacket]

Re: Lenovo V330-15IKB - no picture

Attached. ( I was trying another stuff, so I decided to allow onboard RAM again, since it behaved the same. Just saying that, because on the photo you can see resistor strap on that place ).