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didutgendut replied to Lenovo Y50-70(no touch) power on but no display

in Troubleshooting Laptops, Tablets, and Mobile Devices

07-16-2017, 09:33 PM
Re: Lenovo Y50-70(no touch) power on but no display

okay im going to check KB9022 as soon as possible.
one question is it okay if i get a short circuit when checking those pins ? because those pins looks really close to each others, and i only have a standard multitester leads..
anyway thanks for helping me

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didutgendut replied to Lenovo Y50-70(no touch) power on but no display

in Troubleshooting Laptops, Tablets, and Mobile Devices

07-16-2017, 03:56 AM
Re: Lenovo Y50-70(no touch) power on but no display

here's the measurement when powered on

PL101 20.5V
PL102 20.5V

PL201 2.4V
PL202 2.4V

PL302 2.3V

PL401 19.6V
PL402 3.3V
PL404 5.1V

PL501 19.6V
PL502 1.5V
PL503 19.6V

PL702 1V
PL701 19.6V

PL902 0.9V
PL903 0.9V
PL904 0.9V

PL1102 1.7V
PL1103 1.7V
PL1104 1.7V

PL1201 5V
PL1202 12.2V

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didutgendut replied to Lenovo Y50-70(no touch) power on but no display

in Troubleshooting Laptops, Tablets, and Mobile Devices

07-16-2017, 03:10 AM
Re: Lenovo Y50-70(no touch) power on but no display

is it okay powering it on without the heatsink ? because some coils are under the heatsink and when i powered it on, i can feel warm around the heatsink

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Last edited by didutgendut; 07-16-2017, 03:11 AM.
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didutgendut replied to Lenovo Y50-70(no touch) power on but no display

in Troubleshooting Laptops, Tablets, and Mobile Devices

07-16-2017, 02:54 AM
Re: Lenovo Y50-70(no touch) power on but no display

here's the measurement on coils with battery disconnected and adapter connected

PL101 20.5V
PL102 20.5V

PL201 2.4V
PL202 2.4V

PL302 2.4V

PL401 19.9V
PL402 3.3V
PL404 5V

PL501 19.9V
PL502 0V
PL503 19.9V

PL702 0V
PL701 19.9V

PL902 0V
PL903 0V
PL904 0V

PL1102 0V
PL1103 0V
PL1104 0V

PL1201 0V
PL1202 0V

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Last edited by didutgendut; 07-16-2017, 03:08 AM.
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didutgendut replied to Lenovo Y50-70(no touch) power on but no display

in Troubleshooting Laptops, Tablets, and Mobile Devices

07-15-2017, 10:53 PM
Re: Lenovo Y50-70(no touch) power on but no display

should i check the voltage with or without the adapter connected ?

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didutgendut started a topic Lenovo Y50-70(no touch) power on but no display

in Troubleshooting Laptops, Tablets, and Mobile Devices

07-15-2017, 10:37 PM
Lenovo Y50-70(no touch) power on but no display

hi my laptop display is dead (no image, no backlight, nothing)
when press the power button the keyboard backlight, power light, battery light is on, no hard drive light and the fan spins for a few seconds. also i got a little heat in the heatsink (i guess the source of the heat around PU1102,PU1103,PU1104)
i have tried replacing the ram, harddisk, external display, wiggle lcd cable, reset the power, etc but still no luck..

is there any other sugestion ?
here i attached the board schematic
thanks !...

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Last edited by didutgendut; 07-15-2017, 10:39 PM.
didutgendut replied to Lenovo Y50-70 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

07-09-2017, 05:01 AM
Re: Lenovo Y50-70 Completely dead, no lights at all.

so now after replacing all off those bad things the laptop turn on now but with a dead screen.. when i press the power button the keyboard backlight is on and the fan spin for a while and stop and it shows nothing on the screen. i already double checked the display connection to the board, and everything seems to be ok. what do i need to do now ?

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didutgendut replied to Lenovo Y50-70 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

07-07-2017, 02:30 AM
Re: Lenovo Y50-70 Completely dead, no lights at all.

okay so now im gonna replace those PU1102, PU1103 and the ceramic caps with the new one
wish me luck..

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didutgendut replied to Lenovo Y50-70 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

06-23-2017, 12:09 AM
Re: Lenovo Y50-70 Completely dead, no lights at all.

Oh man, i screwed up again. after few minutes charging the battery PU1103 seems blown up.
1. Is it beacuse i plug the ac adapter without the ceramic caps on the board?
2. i should remove PU1103 and check for the short again right?
...

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didutgendut replied to Lenovo Y50-70 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

06-22-2017, 11:31 PM
Re: Lenovo Y50-70 Completely dead, no lights at all.

Hello my friend, i've put back PU1102 to the board(hopefully soldered well :p)
1. it seems no more short in the board.
2. Plug in the AC adapter, 20V can now past through PQ302
charging light now light up
3. Can i try to power up the laptop without that ceramic cap? is it ok?...

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didutgendut replied to Lenovo Y50-70 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

06-22-2017, 10:14 AM
Re: Lenovo Y50-70 Completely dead, no lights at all.

hello, i just removed the PU1102 but the the problem still exist. resistance between PL301 and GND keep showing just 1,3 ohm.
So i inject 1v again to PL301, the board draw 1,34A from the PSU, and i start searching which component heat up. I found that the component beside PU1102 got pretty hot so i decided to remove it.
After remove that component(i guess it's a ceramic caps?) PL301 doesn't seen shorted anymore, it shows about 5 mega ohm but the meassurements keep moving. i inject 1v again and my...

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didutgendut replied to Lenovo Y50-70 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

06-19-2017, 10:12 AM
Re: Lenovo Y50-70 Completely dead, no lights at all.

ahh, sorry man. I made stupid mistake, i didnt meassure it versus gnd.
Here's the meassurement:
PL1102 17.3ohm
PL1103 17.3ohm
PL1104 17.3ohm

PL902 14.2ohm
PL903 13.2ohm
PL904 13.5ohm

PL502 187.5ohm
PL404 22.08k ohm
PL402 10.15k ohm
PL302 176.1k ohm
PL702 64.3ohm
PL1201 72.1k ohm
PL301 1.4ohm

Yes, i meassure it when injecting. i meassure it again and still no voltages.
After a few...

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didutgendut replied to Lenovo Y50-70 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

06-19-2017, 09:15 AM
Re: Lenovo Y50-70 Completely dead, no lights at all.

hi, sorry for the late reply. i have to take the PSU from my office first. i already follow the instructions you gave.
1. Yes exactly, mine is LA-B111P.
2. Meassurement on all big coil i can found shows 0 ohm.
4. i set the psu to 1V and connect it to PL301, it shown 1,34A drawn to the board. is it normal?
5. i meassure voltage on the coil you mentioned but none of them show 1V.
So the next step is to find other shorted component right? how hot will that component be? after a few...

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didutgendut replied to Lenovo Y50-70 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

06-17-2017, 10:56 AM
Re: Lenovo Y50-70 Completely dead, no lights at all.

Yes, i have bench PSU. Should i keep following instructions you just mentioned or use another method with the bench psu? Because i cant find PJ301....

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didutgendut replied to Lenovo Y50-70 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

06-17-2017, 08:01 AM
Re: Lenovo Y50-70 Completely dead, no lights at all.

there's no voltage at all on the board. would you please tell me how should i start test the board...

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didutgendut replied to Lenovo Y50-70 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

06-17-2017, 07:59 AM
Re: Lenovo Y50-70 Completely dead, no lights at all.

there's no voltage at all on the board. would you please tell me how should i start test the board

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didutgendut started a topic Lenovo Y50-70 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

06-17-2017, 05:35 AM
Lenovo Y50-70 Completely dead, no lights at all.

Hello.
I have a laptop for repair that probably dead.
Has no response at all, neither battery charging, neither on pressing power on, no led lights up.
the ac adapter is all fine i still can get 20v in the input section and all fuses in the input is still good(id pin is good)
when i do a short findings, i find that there is short between PQ302 pin 5-8 and the ground. is it alright ? would you please help me what i have to do next to check?
Schematics of M/B uploaded.
Thanks in advance !!!...

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didutgendut replied to Lenovo G50-30 Completely dead, no lights at all.

in Troubleshooting Laptops, Tablets, and Mobile Devices

06-15-2017, 11:06 AM
Re: Lenovo G50-30 Completely dead, no lights at all.

hi, i have the same problem here. In my case, yes there is short between PQ302 pin 5-8 and the ground. would you please help me what i have to do next?...

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