Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Troubleshooting Laptops, Portable, and Mobile Devices
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 04-21-2017, 01:10 PM   #41
Kashi1712
Member
 
Join Date: Jan 2017
City & State: Brussels
My Country: Belgium
I'm a: Knowledge Seeker
Posts: 39
Default Re: Lenovo Y50-70 (not touch) - Screen LED Backlight

Ok guys, good news, it is working ! Lcd cables had a bad contact on the screen so light is back now ! The ohm resistor was faulty :-)

Thanks again !
Kashi1712 is offline   Reply With Quote
Old 04-21-2017, 01:59 PM   #42
rookieme
Badcaps Veteran
 
Join Date: Oct 2014
City & State: Athens
My Country: Greece
I'm a: Knowledge Seeker
Posts: 204
Default Re: Lenovo Y50-70 (not touch) - Screen LED Backlight

glad to hear that!
rookieme is offline   Reply With Quote
Old 12-16-2017, 03:42 AM   #43
Csabeeboy
New Member
 
Join Date: Dec 2017
City & State: Budapest
My Country: Hungary
I'm a: Knowledge Seeker
Posts: 2
Post Re: Lenovo Y50-70 (not touch) - Screen LED Backlight

Guys, I don't know how to start a new thread, but it's related to the same lcd backlit problem.
Symptom: black screen, otherwise laptop works fine, even external monitors are ok.
Reason: Laptop hinge cover is broken, and when closing the lid, the lid pressed against the bottom part of the screen.
Solution: I ordered a new screen, which only lit up in a very very dim way. Because it did show some dim picture, the back light must not be working.
I tried to ring the fuse next to the 30 pin, and bingo it wasn't working.
I asked for the help of my younger brother who had a soldering station, and he jumped the fuse.
It works!
Attached Images
File Type: jpg 24474757_1775439629135736_176465658_o.jpg (72.5 KB, 28 views)
Csabeeboy is offline   Reply With Quote
Old 01-09-2018, 10:57 PM   #44
wcars05
New Member
 
Join Date: Jun 2017
City & State: Parts Unknown,Ohio
My Country: US of A
I'm a: Knowledge Seeker
Posts: 2
Post Re: Lenovo Y50-70 (not touch) - Screen LED Backlight

So I seem to be in the same boat with a different type of leak... I stumbled upon this thread a while back and I get voltage the whole way to the panel as per: http://diyprojector.info/forum/index...KbmJcxo4TbKDBV

I get ~ 20V on the 4 pins when testing between the GND and Backlight supply voltage. (there are 2 sets of 4 pins that make up the VS and GND going into the panel.

Looks like something died in the screen?

I was curious if there is a way to test for signal for enable/disable and the pwm?

I do have access to a oscilloscope. Looking for some diagnostic guidance before I waste $90 ordering a screen.

Page 21 shows the full diagram of the connector.

pins 28-31 are Back light GND

Pin 32 is enable
Pin 33 is pwm dimming

pin 36-39 are Backlight supply voltage

I figured the odds would be slim that all 10 arrays of back light LED's would go bad at once, but I might be wrong?

Any help is appreciated,
Thanks!
wcars05 is offline   Reply With Quote
Old 09-18-2019, 10:23 AM   #45
Distopik
New Member
 
Join Date: Sep 2019
City & State: Jyland
My Country: Denmark
I'm a: Knowledge Seeker
Posts: 2
Default Re: Lenovo Y50-70 (not touch) - Screen LED Backlight

Hi i have a similar issue and im looking for assistance i swapped the zero ohm resistor and get 20v on one end and 19.7 on the other end with the power supply when the machine is turned off but when i turn it on it drops to 02.9v on both sides of the im assuming it might be the wrong type of zero ohm resistor but im no expert so any help is appreciated
Distopik is offline   Reply With Quote
Old 11-22-2019, 03:55 AM   #46
IceLv
New Member
 
Join Date: Nov 2019
City & State: Koknese
My Country: Latvia
I'm a: Knowledge Seeker
Posts: 1
Default Re: Lenovo Y50-70 (not touch) - Screen LED Backlight

Quote:
Originally Posted by piernov View Post
R375 should be the component circled in red in the following picture. Maybe yours is blown too.

(Source: http://www.elektroda.pl/rtvforum/topic3228153.html )
I know this is VERY OLD post, but just wanned to say thanks a lot! Just replaced screen cable too and lost backlit, this picture saved me! That resistor/fuse was blown and i solered those 2 pins directly and everything works! Thanks!
IceLv is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums 2003 - 2019
Powered by vBulletin ®
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 01:13 AM.
Did you find this forum helpful?