z50-70 nm-a273 no display

[ous154]

hi guys i have lenovo z50-70
mb.nm-a273
no display en lcd but working on vga i tried everything
if any one have any idea plz help

[KillerFlash]

Re: z50-70 nm-a273 no display

Sir, try to check your LCD cable to motherboard if their is faulty wiring and kindly double check your lcd panel if their is display but no back-light, how ever try to use other spare of lcd panel to make sure that the motherboard is working via LCD.

[ous154]

Re: z50-70 nm-a273 no display

Thanks for reply but I tried another lcd and cable it's the same

[Ahmed ashour]

Re: z50-70 nm-a273 no display

I have the same issue
- tried BIOS
- another LCD and LCD cable but still gives no display
Any help plz
Thanks in advance

[SMDFlea]

Re: z50-70 nm-a273 no display

Check the LCD POWER circuit in the schematic

[Ahmed ashour]

Re: z50-70 nm-a273 no display

thanks buddy, I'll check it then give you fee back later

[Ahmed ashour]

Re: z50-70 nm-a273 no display

Check the LCD POWER circuit in the schematic

I couln't fix it unfortunately, so if there is any suggestion i'd be pleasured
and frankly i couldn't understand the LCD POWER circuit properly

[mielta]

Re: z50-70 nm-a273 no display

Hi
First messure voltage at JEDP1 Pin 1,14,16,20,21,23,30 an write it here

Pin1- ...V
Pin14-...V

[Ahmed ashour]

Re: z50-70 nm-a273 no display

Hi
First messure voltage at JEDP1 Pin 1,14,16,20,21,23,30 an write it here

Pin1- ...V
Pin14-...V

Thank you in advance for your concern buddy
as you requested
Pin 1 = 19.8 V
pin 14 = 0 V
pin 16 = 0 V
Pin 20 = 0 V
Pin 21 = 3.3 V
Pin 23 = 3.3 V
Pin 30 = 3.3 V

[mielta]

Re: z50-70 nm-a273 no display

Pin20 goes to +3vs the same witch goes to pin23 but on pin 20 there is an resistor R21
please check him

[Ahmed ashour]

Re: z50-70 nm-a273 no display

They don't name the resistors on Motherboard, that's why i couldn't find R21, Is there any way to find it

[mielta]

Re: z50-70 nm-a273 no display

follow the line from pin20 with an multimeter on Ohm

[Stevie2001]

Re: z50-70 nm-a273 no display

Try get boardview if u cant find free buy it

[technician37]

Re: z50-70 nm-a273 no display

i almost same problem..

sir how if pin 21 is 0v?
gpu heat up but processor is not.
bios have 3.3v same with power switch

it is possible reflash BIOS?

thanks in advance..

[caspian]

Re: z50-70 nm-a273 no display

If it has display on a VGA monitor and the GPU heats up too much while a heatsink is on the GPU, that means the GPU may be defective. So it is not a Bios issue. However, more tests are required to make sure the GPU is defective.

[on/off]

Re: z50-70 nm-a273 no display

sir how if pin 21 is 0v?

First make sure your problem NOT on LVDS cable or LED panel.
Connect your mobo with external monitor and display have working with it.

Pin 21 of LVDS conn doesn't appear:
DMC_DATA and DMC_CLK doesn't get signal 3.3V
LVDS not connect
Signal PCH_ENVDD not going HIGH.

Test and measure with LVDS cable connected without adapter or battery:
On LVDS conn Pin 21 not low resistance.

Test and measure with adapter or battery ( adapter preferred)
Check signal DMC_DATA and DMC CLK have correct signal. then
Check PCH_ENVDD signal.

it is possible reflash BIOS?

I think not Bios issue.