Power issues with AC input NP9150

Anyone ever have an issue with DC losing power due to a connection issue with the power jack? Right now I'm pretty sure I've narrowed the problem down to something at or near the power input jack, because with the cord in the right position or with the right pressure inwards the power works fine, but I'mat a point where power disconnects far too easily, to the point of me needing to use the laptop at a certain angle. This issue has been getting progressively worse, so either degradation or cracked wiring? Is there an easy fix I can do at home that worked for anyone else?

Also, thread title should say DC input.

 

It could be the jack needs replacing, moving it around could start causing PCB damage if that's the case.. I take it the cord from the PSU looks ok?

 

The little metal bits on the inside of the plug on the adapter end could be bent too far apart over the years to make good contact with the centre pin on the jack. Sometimes able to be bent back into place with something strong but tiny enough to get behind them through a gap, like a sewing needle.

 

Repeated stress could be breaking the jack off the PCB. Might need to get that part replaced.

 

I tore down the laptop so I could get a good view of the jack on both sides. There's some cracking and brown residue everywhere. I think I saw something about the DC jack burning up over time being a very common issue, so I think that's what happened. I did try resoldering the main lead but that didn't do much, so I've decided to buy a new DC input jack along with a soldering kit to properly replace the DC jack. DC jacks can be found for really cheap on ebay for anyone looking to do the same.

The PSU cable is fine. I don't think the end uses pins like that. I tried bending whatever is in there up but it isn't working. Again I don't think the power cable for this model works that way.

 

That definitely sounds like it's stress breaking it. Make sure with the new one you're extra careful about plugging and unplugging it.

 

I took another look at the DC input side and did see pins that can be bent. I tried messing with it and the result was I was almost fooled into thinking I fixed it, but I still suspect the issue isn't just the contact pins themselves but also something with the connection from the pins to the motherboard. Maybe even something else like capacitors even though nothing looked blown out. I'm not really sure where contact between the power cable end and pins is supposed to be viably made, because I feel like I'm able to get good contact with metal but maybe not in the right places. Maybe corrosion has caused issues? Either way, keeping a stable DC power input is nearly impossible now. Even when I get a sweet spot of pressure on the cable it doesn't last more than a minute before a momentary break hits.

I still think replacing the entire DC jack should solve the problem, but there's something else. In the process of bending down one of the contact pins (which was very much flattened over time due to use compared to the others) inside of the DC jack, I accidentally caused some shorts with the power supply. The power supply still works and the laptop is fine so I don't think anything was damaged, but there were sparks at the DC jack with burn residue left. This entire situation is just so weird, but I'm still excited to give the whole soldering thing a go once my stuff comes in the mail.

edit: I have DC input running stable for now after some more pin bending, but I'm getting similar behavior that I've seen in the past where the battery has trouble charging, except now the battery can't be charged at all instead of intermittently. So I have to keep DC in without the battery installed. Should work for now until replace the jack.

 

Careful, that 19v can have a large amount of current put behind it, don't mess with the tip when it has been on recently (the capacitors can retain a lot of charge for a while).

Be sure to follow best soldering practises, videos from the like of Louis Rossman can help, if you don't do it right you could get shorts or cracking in the future.

 

I'm in the DC jack replacement process at the moment. The positive pin (#1) was burning up black to the core at the point of contact with the motherboard. I will update later.

edit: IT'S DONE! IT'S FINALLY OVER! DC power works and battery charges with no drops! Just don't do what I did and get impatient by drilling through the old leads due to having a cheap soldering iron that doesn't melt the old solder. I worked so long trying to wick up the solder and know I should have tried more to pry the leads out with force along with jack at the beginning. I've learned some lessons. But despite the drilling, the new jack works perfectly!

 

I have found applying a small amount of melted solder helps the heat transfer and get it all melted.

 

I tried that for a bit and it wasn't doing much, but maybe I wasn't doing it right. There's a lot of things I could have done better or should have had beforehand but luckily with the new jack working I didn't suffer major consequences.

 

Yeah drilling the PCB, that's pretty desperate. At least it is working now though, I'm guessing the pin had a crack in it.

 

The positive pin was black like charcoal to the core at the through hole, and there was definitely cracking. You could wiggle the pin around with a few mm gap. So power connection was being lost because those issues, and the jack contacts probably had nothing to do with it.

I just wanted to get it over with because I already had all of my equipment out and didn't want to wait 1+ weeks to get a better iron or a heat gun or something. I knew that as long as I didn't drill out the circuit that the job would be successful. My gut told me it would work but I was really anxious to make sure it actually worked and was sooo happy when I first plugged the power into the new jack for the first time and saw the LED turn on.

I haven't had any issues with power since. I even have a couple extra jacks if I ever need them but seeing the problem took 5 years to develop I will probably not be using this laptop by the time I'd need to replace again.

edit: On another note, I've also fixed my 7970m again by baking it. What a ride it's been with this laptop...I've had power issues multiple times, GPU issues multiple times, keyboard issues multiple times, and it's all been fixed over the years for a non-insane amount of money. It was about $100 for external repair after I made the giant mistake of inserting the wrong power cable into the laptop, then $40 for the recent soldering supplies and $60 for the two keyboards I've had to purchase for malfunctioning keys. The thing is still chugging and working great. Still an ivy bridge i7, a gaming relevant GPU that can be upgraded, 16GB RAM and a pretty decent color gamut 1080p screen. All from 2012 for $1500, still little reason to upgrade (and the DC jack problem really had me ready to get the casket out). I wonder if I'll decide to put in a GTX 1060 in a couple years and keep it going for a decade.

--Update 8/23/2018--
After 2 months the solder joint for the main pin cracked again. No burning this time, just wear from inserting and using the power cable cracked what was probably not the best soldering. I had to go back in and resolder the joint and the laptop is working fine again. I tried to make extra sure the solder flowed deep into the hole but I expect cracking again.

However, I did take the chance to try a method of adding redundancy for the P150EM that I saw on youtube that involves soldering a single wire from the end of the main pin to an empty contact through hole on the PCB on the outer ring of unused contacts. If you're looking down on the underside of the jack with the input facing towards you, this through hole is on the very upper right corner. It's supposed to be used for the P170EM style jack and thus would be occupied by a pin on the P170EM motherboard. However, after I soldered the wire, plugging in the power jack caused quite an audible spark and the laptop would showed no LEDs or power on with battery nor DC in. Removing the wire brought the LEDs and laptop back to working condition. I don't really know what went wrong, like if that video was wrong or whatever but I recommend not adding the wire unless you really know what you're doing. I'm not an experienced solderer and I'm no electrical engineer so I don't know how exactly I needed to do that codification but clearly I did it wrong. Yet again another bullet dodged with this laptop.

edit 10/1/2018:
I think I had to resolder the joint 3 or 4 times with the solder that came with my cheap solderng kit before I decided to buy better solder and some liquid flux to aid the welding. It's been over a week and the new solder seems fine. If this post hasn't been further updated then assume it's still working. I used Austor 0.6mm Lead Free Solder Wire with Rosin Core and AMTECH NC-559-V2-TF flux.

 

You are lucky it did not catch fire or fry something! Here's to some more happy years.