Thank you, [USER="169897"]piernov[/USER]. Actually, you hit the jackpot. Amazing deduction!
I tried to hook a PSU on the LDO 3.3V output ( even, if there is kohm range ), and current consumption was around 300 mA. And no, it was no EC. There was two schottky diodes in its way, and behind second diode was like zero point something resistance to ground. Injection of 0.9V at that point heated up PCH in up-right corner of its crystal. So yeah, nice to meet you, donor board.
I only wonder, if this was just random failure, or the customer did something ( he previously...
YellowJacket
Senior Member
Last Activity: 04-15-2024, 09:05 AM
Joined: 12-27-2020
Location: Slovakia
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Looks like I am not alone, who is lost in this case without schematic. So to finish it somehow - do you guys at least have any idea, how to confirm dead EC ( corrupted EC firmware included ), eventually dead PCH, without schematic?
Also, is 1.4 ohm resistance to ground on that 1V power rail too low?Leave a comment:
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Thank you [USER="149220"]mcplslg123[/USER] , you gave me really difficult task though.
I tried to analyze the circuitry as much as I could, and I looked around both 5V coils and the 3.3V one. But all three had nearby an IC, which was hard to find datasheet of. First picture is an IC connected to 5V coil on the left ( from picture in first post, 3k5 resistance ). Second picture is an IC connected to 5V coil on the right ( 22R5 resistance ). Third picture is an IC connected to 3.3V coil ( 3k3 resistance ).
Anyway, I was able to measure 3.3V on one capacitor nearby...Leave a comment:
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Hi [USER="295753"]mon2[/USER]
1.) I flashed there original bios dump, after cleaning its ME region. As I mentioned, the laptop behaves always the same though. If you think, it is bios related, let me know, I will ask here on badcaps for another dump
2.) First DCIN mosfet is AON6428, second mosfet is AON7414. Charger IC is BQ738
- about LEDs : the one on the charging port, it is all time turned off. Then, there are three LEDs under power button. These LEDs are meant to shine together I believe, and this power button lights all the time, from...Leave a comment:
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HP 13-ad017nc - doesn't start
Hi all,
I got this laptop to fix, this is known history - firstly, laptop had some troubles with turning ON ( turned on at third attempt, or so ). Then, during windows installation, USBs were not working at all ( it was unable to detect any USB flash stick ). Even after installation and looking for some drivers. Then a guy told me, he tried to install some software ( from last conversation, it should be "any desk" software ), and during installation the laptop shuts down. From that moment, it doesn't turn on. After connecting the charger, there is no light on charging port... -
HP 13-ad017nc ; Board number: 6050A2919201-MB-A01
Hi friends,
I would like to kindly ask for schematic or boardview to this laptop:
Device: Laptop
Brand: HP
Model: 13-ad017nc
Board Number: 6050A2919201-MB-A01
I am unable to find it anywhere. Hope, it is available. Thanks in advance. -
Another solved case thanks to you, Lotas. It works now ( removed all resistors on right side, where was smaller resistance ).
Big thanks to you!Leave a comment:
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Thank you lotas (again).
Left and right side atached. I believe, I should check around 0 ohm resistors, right? Resistance to ground is in Mohms on CKxxx though. But there is only 20 ohms on VSTB1 and VSTA1....Leave a comment:
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Dell P2416DB - no picture
Hi friends,
I am here for asking for a little help with this monitor. It reacts to pressing the power button, but the only thing I get is working back light, with no picture. I was measuring all power voltages, you can see them in attached picture. There is 3.3V on the SPI ROM chip, and I can see healthy-looking communication on it ( pin 1 is changing ) after powering on. I can see nice clock signal on both crystals. I am even able to measure some low voltage data signals on LDVDS cable. So I believe, my issue in on the panel itself. I proved it by measuring VGH1 signal on a test...Last edited by YellowJacket; 01-16-2024, 07:49 AM. -
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 )....Leave a comment:
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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.Leave a comment:
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Re: Lenovo V330-15IKB - no picture
CPU is warm - the longer is board running, the more is temperature rising ( until some point of course ).
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 - [url]https://www.badcaps.net/forum/showthread.php?p=1281467#post1281467[/url] ( 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...Leave a comment:
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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 [B]19V_DCBATOUT[/B] 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...Leave a comment:
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Lenovo V330-15IKB - no picture
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...Last edited by SMDFlea; 10-19-2023, 06:49 AM. -
Re: Lenovo bios V330-15IKB
Thank youLeave a comment:
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Re: Lenovo bios V330-15IKB
So do you mean, that firmware, which linked hoaca388, should work, right?Leave a comment:
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Re: Lenovo V330-15IKB BIOS request
Thank you, hoaca388, but sadly, it doesn't work. No picture, CAPS LOCK is turned ON. Fan is spin firstly, then it shuts down. And after few sec it spins all time.
Maybe it is only for S/N: R90QX3JH? My serial number is R90Q6BW3.
// CPU is Core i5-8250uLast edited by YellowJacket; 10-18-2023, 01:42 AM.Leave a comment:
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Lenovo V330-15IKB BIOS request
Hi friends,
Device: Laptop
Brand: Lenovo
Model: V330-15IKB
Board number: LV315KB ; 17807-3 ; 448.0DC04.0031
Serial number: R90Q6BW3
I got this laptop with damaged bios chip, so I am trying to flash a new one, from lenovo support site: [url]https://pcsupport.lenovo.com/sk/sk/p...3-B07A93E0428C[/url]
I am unable to extract bios binary from original exe file, since I have no original dump. Is it possible without original bios dump?https://Lenovo V330-15IKB BIOS reque...> Hi friends,Leave a comment:
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Asus VX238H - pink area over picture
Hi friends,
I got this monitor, which works perfectly fine, except there is pink discoloration over right side of the screen ( picture1 ). When I disconnect LVDS cable, there is no sign of pink color, so its not backlight issue ( picture2 ). I took a closer picture of the upper right corner, you can see even some kind of pixel defects. Its only on that pink area ( picture3 ).
I believe, there is some problem inside the panel, the question is, if it is fixable. I have never met this kind of issue, so I really appreciate little help from you guys. What I tried so far - interrupt...
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