# How to test between a bad DC Jack and Bad Motherboard?



## Dennis_Fused (Feb 3, 2010)

Any information would be appreciated.


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## Techie19 (Feb 10, 2008)

Most common symptom of a bad DC Jack is having to hold the AC Adapter cable at a certain angle for it to make good contact with the DC Jack. This is due to the DC Jack being loose where it connects to the motherboard. The soldering points have become loose/damaged. On some laptops the DC Jack connects to the motherboard via a wiring harness. No soldering required. On these types the wiring harness becomes damaged by the wires breaking. 

A bad motherboard is harder to confirm but usually if there is no sign of life, no sounds, no fan spinning, no lights flashing or turning on, then this would be the case of a bad motherboard. 

Before ruling out a bad motherboard or DC Jack, you want to confirm that the AC Adapter is in good working order and it is putting out the proper voltage. You can test the AC Adapter with a multimeter. 

Hope this info helps.


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## Dennis_Fused (Feb 3, 2010)

Techie19 said:


> Most common symptom of a bad DC Jack is having to hold the AC Adapter cable at a certain angle for it to make good contact with the DC Jack. This is due to the DC Jack being loose where it connects to the motherboard. The soldering points have become loose/damaged. On some laptops the DC Jack connects to the motherboard via a wiring harness. No soldering required. On these types the wiring harness becomes damaged by the wires breaking.
> 
> A bad motherboard is harder to confirm but usually if there is no sign of life, no sounds, no fan spinning, no lights flashing or turning on, then this would be the case of a bad motherboard.
> 
> ...


Thanks for the detailed reply!
My reason for asking, and it appears that my issue falls into neither of those categories, my Laptop will show an LED light for 5 seconds before turning off again. No Fans or signs of life otherwise. I pulled the Motherboard apart, nothing but the RAM and CPU in with just the power switch and power to the mainboard plugged in, and the same thing occurs.

The DC Jack is nice and secure however.

I also tried this with and without the battery.
Also, I have two Adapters, both showing the same symptoms.
I have a 2nd laptop that uses the same adapter and the same battery, it is working fine with the battery and adapter.


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## ALR5 (Oct 16, 2012)

What is the model of your laptop? This can also be caused by your GPU/solder spheres needing reworked. I rework motherboards for a living and I see this symptom as well and are revived by reworking the chipset.


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## Dennis_Fused (Feb 3, 2010)

ALR5 said:


> What is the model of your laptop? This can also be caused by your GPU/solder spheres needing reworked. I rework motherboards for a living and I see this symptom as well and are revived by reworking the chipset.



It is a Gateway NV7316u


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## ALR5 (Oct 16, 2012)

Yeah, you have an ATI Radeon HD 4200 which is known to cause this type of issue like some nvidia chipsets. Bet you anything it needs a motherboard rework/reflow. Is this a personal laptop or a customers?


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## Dennis_Fused (Feb 3, 2010)

ALR5 said:


> Yeah, you have an ATI Radeon HD 4200 which is known to cause this type of issue like some nvidia chipsets. Bet you anything it needs a motherboard rework/reflow. Is this a personal laptop or a customers?


Personal.
I picked it up for $25 from a charge off hoping I could get it working :/


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## Dennis_Fused (Feb 3, 2010)

So I will be trying the Oven baked Reworking method tonight, with any luck I'll have a working laptop by the morning!


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## Dennis_Fused (Feb 3, 2010)

Alright, so oven for 10 minutes at 385 oven temp.
Motherboard isn't recognizing the battery being attached so won't charge.
Doing basically the same thing as before.
I left the oven open for about 1 minute before hand and ended up only leaving it in for 8 minutes because I jumped the gun now that I think about it.

Would that have made a big difference?


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## ALR5 (Oct 16, 2012)

Yes it can...If you don't get ALL the solder spheres, that can throw an error as well. It only takes one out of all of them to cause a hiccup. I really hate oven and heat gun tricks so I can't input much here as I have never done those methods. Just know you need to reach 217c-225c to get all them balls reworked...I hope you insulated the board pretty good before throwing it in there? lol


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## Dennis_Fused (Feb 3, 2010)

ALR5 said:


> Yes it can...If you don't get ALL the solder spheres, that can throw an error as well. It only takes one out of all of them to cause a hiccup. I really hate oven and heat gun tricks so I can't input much here as I have never done those methods. Just know you need to reach 217c-225c to get all them balls reworked...I hope you insulated the board pretty good before throwing it in there? lol


So it may have been due to it not reaching the sufficient temp.

I'd really like for this method to work, simply because I don't have the kind of money it takes to possibly get a heat gun or the such, for it to not work :/


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## pctoxicated (Sep 22, 2012)

That method will work about 3 times id say in a month youll end up replacing the entire board. The oven method actually does more harm then good.


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## Michael Kennedy (May 30, 2012)

*Symptoms of a broken DC power jack:*
- The laptop only operates when you hold the DC power plug in a certain direction (DC jack is broken or loose).
- The laptop only runs on battery power (no power is getting through the DC jack).
- The laptop gets no power at all.
- The laptop will not charge the battery.
- The laptop switches from AC power to battery power intermittently due to a loose or broken power jack.
- The laptop suddenly shuts off.
- The DC jack may feel loose.
- Sparks come out of the back of the laptop when you insert the power plug into the DC jack.

*How some repair centers handle DC jack repair:*
Most service centers don't want to deal with this problem by attempting to repair the DC jack. Many, including the large nationwide stores and the laptop's manufacturer, will either tell you the machine is not repairable or that they will need to replace the motherboard. These quotes usually run from $250 to as much as $800. They choose to ignore the fact that a broken DC power jack can be repaired without a motherboard replacement because they are not equipped with the tools or training to do DC power jack repair on your laptop.


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