Most common culprit of laptop screen flickering?

[GoodEnough]

2 part question.

HP G62-340US
Screen is flickering.

Google indicates the video cable may be the culprit.
Or, do you think the MB is bad?
Or, do you think the LCD screen itself is bad?

In your experience, can you rank the most probable culprits?


Also, I disassembled the laptop and noticed the existing video cable says
DD0AX6LC005 <-- (5 at the end, not 1 or 2)

I ordered this for $5.
It gives a model number of DD0AX6LC001/002

Will this one be compatible?

 

[denis280]

Can you try with another monitor on it

 

[Ketchup]

If you tilt the screen and the image changes or goes back to normal, it is probably the cable.

Here is the cable I get when searching your laptop model:
http://www.amazon.com/350401C00-600-.../dp/B009N72P6S

It doesn't look much like the one your ordered.

 

[GoodEnough]

Tilting doesn't have any effect.
It flickered when I booted up in a disassembled state.

The 2 cables do appear the same, if you look more carefully.

Thanks.

 

[GoodEnough]

Can you try with another monitor on it

Not really, it's a laptop. No spare parts on hand.

 

[Burpo]

AMD or Intel? That doesn't look like a cable problem.

 

[Ketchup]

Tilting doesn't have any effect...

In that case I tend to agree with Burpo, it is probably not a cable problem.

A refurbished board is at least $70, so it's up to you if it's worth it.

 

[ArisVer]

Hook it to an external monitor to check if it's a screen/cable issue.

 

[corkyg]

Not really, it's a laptop. No spare parts on hand.

That really doesn't make sense. A laptop has a video out port - that suggestion means to connect it to an external monitor or TV - no spare parts involved. ???

Also, your laptop backlight is LED powered by DC. LEDs can sometimes flicker when brightness is low. Try going into Power Management and changing any settings that might be aimed at battery saving, etc. Turn up the power to max performance.

 

[GoodEnough]

I hooked the laptop to a normal VGA monitor.
There was no flickering!
What have we proven? That the motherboard works correctly?
Have we also proven the video card works, since it IS generating a clean image.

Issue lies with the LCD?

LCD cable will arrive in a few days.
If that doesn't work, what is the next variable?

Replace the actual LCD for $50?

 

[Ketchup]

They are a package deal. If the external connection to another monitor looks fine, it's the screen or cable. If not, it's the video chip on the motherboard.

 

[GoodEnough]

So, it's either cable, LCD, or video chip (MB)

If cable doesn't work, what's the next step?
Replace the $50 LCD?
If still no good, then replace $75 MB?
Or the other way around?

But, a bad video chip (for LCD), can still provide a good VGA signal?
This would mean new motherboard?
Mine is labelled DA0AX2MB6E1 and says AMD.
What would I need to swap from the old MB onto the new? CPU? Fan?

This Ebay ad

and this one and for a MB with dead video implies the video dies on these MBs?

Try new MB first?

 

[inachu]

From my historical viewpoint what has happened to that LCD in your picture.

Water damage
loose wire connector.
wire is damaged or solder breaks free(REFLOW)
damage to the video card- If so by also attaching external monitor. If same then bad video card.
Laptop could have taken a big hit of static discharge.
Ran a few times with the laptop outside to and from the car IN THE RAIN. smooth move exlax!
Always running laptop on the bed thus cooking the insides as the fan is below the unit trying to cool off the laptop but no you prefer to cook it instead and make the bed toasty warm

 

[GoodEnough]

I reseated the video cable while the LCD was apart, and that wasn't it.
New video cable here in a few days.

Video card is good b/c VGA out works fine.

Overheat in bed could happen.
Is the exhaust fan on the side or bottom?
Overheat means new MB ?

 

[ArisVer]

If the CPU fan is constantly at full speed you have heat problems.

Depends on the model, maybe at the back.

 

[denis280]

Overheat in bed could happen

Never never put the laptop right on the bed.place a board under it.otherwise it will pick up dust and fabric from the bed.

 

[Matt1970]

I am not going to say anything to jinx your chances with the new cable.

 

[GoodEnough]

I am not going to say anything to jinx your chances with the new cable.

You're not very optimistic, are you?

If it's not the cable, should I order an LCD or a motherboard?
I still don't know how to rule the next one out.

 

[corkyg]

Did you try anything at all regarding power to LEDs in the screen? Does the problem exist when running on A/C only with no battery? There is a flicker problem with some LEDs when running at low power to save battery.

 

[GoodEnough]

Yes, the screen flickers regardless of using the AC adapter cord or the battery.

 

[GoodEnough]

In case I need a new MB,
The serial number on the MB is DA0AX2MB6E1 (Rev E)

Is this the ONLY model number I can search for, to find a replacement MB?
What other MB's can I seamlessly fit into a HP G62-340US?

Actually, I see Ebay auctions for G62 MB's under serial number 592809-001
I also do see that number on my MB, but near the RAM slots.
It almost implies that 592809-001 is the RAM serial number.
IS is safe to assume I can use the MB's sold as 592809-001 ?

 

[GoodEnough]

One more time....
When the VGA output works, can I rule out a bad video chip/motherboard?

I think I will order a new LCD/inverter if the cable doesn't fix it. $50

 

[corkyg]

Krrp in mind that your particular screen is LED illuminated, not CFL. As I have said before, a common cause of LED flicker is running at low power. Have you check your power management settings for that?

Also, AFAIK, LEDs do not use an inverter.

 

[Matt1970]

You're not very optimistic, are you?

If it's not the cable, should I order an LCD or a motherboard?
I still don't know how to rule the next one out.

I think I can answer that without jinxing you. I have only seen one laptop have good video to an external display but would not work right to the internal even after swapping the screen and cable. So odds are it's either the cable or the screen.

In case I need a new MB,
The serial number on the MB is DA0AX2MB6E1 (Rev E)

That actually is your motherboard model number.

 

[GoodEnough]

Krrp in mind that your particular screen is LED illuminated, not CFL. As I have said before, a common cause of LED flicker is running at low power. Have you check your power management settings for that?

Also, AFAIK, LEDs do not use an inverter.

My LCD screen has a waferboard on the back (CFL?)
I think this is called the inverter. The back looks like this.
Is that motherboard strip called the inverter???

I think I can answer that without jinxing you. I have only seen one laptop have good video to an external display but would not work right to the internal even after swapping the screen and cable. So odds are it's either the cable or the screen.

The $5 cable worked in my laptop.
However, it did not fix the flickering.

So, I am now going to order an LCD see if that fixes it.
None of the $60 LCDs come with an inverter.
http://www.ebay.com/itm/230739252589?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT
http://www.ebay.com/itm/350657402124?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT
http://www.ebay.com/itm/360524326969?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

But, since the inverter may be the root of the problem, I don't want these right?
My model number for LCD is LTN156AT09-H04.
Can anyone help me find one that comes with a new inverter attached?



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