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Re: LENOVO Missing 5v/3v voltages
If you look at datasheet abs max Volt of en is 25v
I read it wrong?Comment
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Re: LENOVO Missing 5v/3v voltages
I read a post on a russian forum that pin 11 is indeed 19V .Just to be sure though inject voltage voltage on theat but but keep it low and slowly crank the voltage up.If you can get up to 19V then run a jumper between 2,3,4, or 5 to 11Comment
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Re: LENOVO Missing 5v/3v voltages
jumper on pin 11 checking voltage on all pins
PU401
PIN1- 0V
PIN2,3,4,5 - 19V
PIN6 0V
PIN7 0V
PIN8 0V
PIN9 0V
PIN 10 0V
PIN 11 19V
PIN12- 0V
PIN13-0V
PIN14-0V
PIN15-1.3V
PIN16 - 0V
PIN17- 0V
PIN18-0V
PIN19-0V
PIN20-0V
PU301
PIN1 - 19V
PIN2 - 19V
PIN3 - 19V
PIN4 - 19V
PIN5 - 19V
PIN6 - 5.8V
PIN7- 0V
PIN8 -0V
PIN9-0V
PIN10-0V
PIN11-0V
PIN12-19V
PIN13-19V
PIN14 -19V
PIN15- 5.8V
PIN 16- 0V
PIN13Comment
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Re: LENOVO Missing 5v/3v voltages
Pu301 is ok
Change pu401
Check capacitor pc422
Apply 3.3v with dc at pc422 and check with multimeter voltage drops or stable if stable change pu401Last edited by stingerchamp; 01-08-2021, 10:55 PM.Comment
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Re: LENOVO Missing 5v/3v voltages
Yes remove itComment
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Re: LENOVO Missing 5v/3v voltages
Confirmed
Change pu401 and likely KBC as wellComment
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Re: LENOVO Missing 5v/3v voltages
Good day sir I hope you can help me again I already cahnge the PU401 ic but I got the same reading on all pins
PU401
PIN1 - 0V
PIN2 - 19V
PIN3 - 19V
PIN4 - 19V
PIN5 - 19V
PIN6 - 0V
PIN7 - 0V
PIN8 -0V
PIN9 -0V
PIN10 -0V
PIN11 -19V
PIN12 -0V
PIN13- 0V
PIN14 -0V
PIN15 - 0V
PIN16 - 0V
PIN17 - 0V
PIN18 - 0V
PIN19 - 0V
PIN20 - 0V
ive tested the impedance of PL401 7KOHMS
PL402 27 Kohms is this normal sir?Comment
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Hello, I've been struggling with this one today. I'm troubleshooting a Lenovo 300-15IBR (board BMWC1/BMWC2 NM-A471) that turns on the power LED and does a bit of fan spin but nothing else. 3v3sb and 5vsb present, no 1.05v, no 1.35vddr, no vcore, no 1.8vsb.
BIOS has been reflashed with one I found here, supposedly tested OK by someone else. I don't have an EC programmer unfortunately.
I looked around and SYSON is 0v, SUSP# is 0v too. Forcing them to 3v3 enables the 1.35v rail, but the 1.05v and 1.8v rails are still missing (generated by PU704). EN_1P05A signal is 3.3v, and IN_1P05A... -
Hi all,
I got a Lenovo Thinkbook 16P G2 ACH on the bench with a botched BIOS (somehow my client blanked it). I restored the laptop and got it up and running with original BIOS from Lenovo Support website.
My problem is now that the machine details are missing in the BIOS (Serial Number, MTM, etc.)
I tried to write the details with the Lenovo Uone Tool but had now luck. It is giving me an error: "ERROR: Locate protocol with LenovoEeprom, Status=[e]. EEPROM fail when reading or writing data."
I am now asking here for help if anyone knows how to do this in... -
I have a TCL 55P6US with sound and backlight but no picture. This model does not have a T-CON board, and the right (rear perspective) panel board is fed from the left panel board. I have not been able to induce any change by disconnecting the secondary panel board or the tape cut-off method on the primary board.
There are a bunch of voltages missing on the panel boards. I can't find any shorted caps of the panel boards, and all of the missing voltage rails read in the kiloohms, which leads me to suspect the issue may lie on the circuit board, rather than a short in the panel.
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I've got an MSI Z390-A Pro motherboard that starts up fine, but it's missing the VCORE (and VGT) voltages. All of the other voltages are present (e.g. VCCSA, VCCIO) and I know the CPU (i7-9700k) is good. Now, the original PWM controller (UP9521P) had an internal short and I replaced it with a new one. All of the enable signals look good. The problem seems to be the PWM signals going to the MOSFET drivers. I checked them with an oscilloscope and they are all flat 1.5V with no pulses. I don't know why this would be and I'm not sure where to look next.Today, 01:25 AM -
Can someone please help me.. Mosfet is missing on this motherboard (Lenovo L340-15IRH) I cant find the part number.. Can someone please send me a picture or part number of the mosfet missing on the board.. Thankyou!
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