Skip to main content

Device repair and information for laptop computers in the HP G series.

110 Questions View all

Power Button Short Circuit?

I have a 15-g050ca laptop that was given to me. I found that whoever had tried to take it apart in the past had ripped the ribbon cable off the power button board. I was able to jump start the computer and verified that there were no other problems besides the broken button cable. I bought a new power button assembly but it did not seem to work. I plugged the power in and unplugged the ribbon cable from the mother board but in the process it triggered the machine to power on. While it was powering on I reinserted the cable and closed the clip but a few seconds later it shut down. As I pulled the cable out it started up again. I believe the system is behaving exactly as it would if I powered it on but then held the power button down until it shut down. Thinking I must have gotten a defective power button board I returned it and got another. Unfortunately, the replacement is doing exactly the same thing. Is it likely that something is shorted on the motherboard or am I simply not reassembling the cable properly?

Answer this question I have this problem too

Is this a good question?

Score 0
Add a comment

1 Answer

Most Helpful Answer

Hi @larry767 ,

Just verifying that the Power button board you have is part # 749650-001? Zoom in for a closer look

This is the specified part number for the power button board shown on p.46 of the hardware and service manual for the laptop, taken from this webpage.

On p.46 you will also find the necessary pre-requisite steps and then the procedure to remove / replace the power button board

What is the board number of the motherboard?

It may be possible to find the schematic of the motherboard by searching for (insert motherboard board number) schematic. Worth a try anyway

Was this answer helpful?

Score 2

5 Comments:

Yes, that part number is identified in the Amazon part I ordered and received (https://www.amazon.ca/gp/product/B073ZZJ...). I took a video of the issue I'm experiencing that might clarify what I'm seeing (https://share.icloud.com/photos/0iXMOvWh...).

by

Hi @larry767 ,

To me it appears as though it is operating in reverse to what it should, as you most probably have already concluded. It is as though the power button was being held operated when it clearly wasn't

You did say that the cable was ripped from the power button board and not from where it is connected to the motherboard, is this correct?

If you have an Ohmmeter, with the cable disconnected from the motherboard can you test the connections from the 4 connection points visible on the motherboard below the connector (as seen in your video) to the actual pins in the connector to make sure that they have continuity and are not shorting out inside the connector itself. (the shorting out might be noticeable if you can visually inspect the pins in the connector).

I'm suggesting this as without a schematic it is difficult to know what a good test is.

It could be faulty components on the motherboard around where the cable connects to or perhaps I was wondering if the BIOS might have been corrupted in some way.

Try going into BIOS and selecting the option to load the BIOS to default settings, restart the laptop and see if this has any effect.

Otherwise since you have replaced the power button board and assuming that the replacement was OK the BIOS (which controls the operation dependent on inputs) is being fed incorrect information.

You would need the schematic diagram of the power up / down section of the motherboard to determine what the input should be before startup.

What is the board number of the motherboard and do the components around the cable connector on the motherboard (assuming that some may be associated with the power button circuitry) appear to be OK?

by

I still have the old button (ribbon cable detached and pulled one of the pads off) so I was able to confirm that the button does function by measuring continuity between the appropriate pins (identified by googling the motherboard number and schematic as suggested by jayeff). I had already returned one switch that I bought from Amazon and sadly, I guess the replacement they sent is also defective. I measure continuity regardless of the switch being pressed or not - the switch itself is always on. So, I guess I return and try again. I'll maybe see if I can find an alternate source.

by

Hi @larry767 ,

If the button on the original board is OK and you are handy with a soldering iron and handling smd components and don't want to return the replacement board, can you swap over the buttons?

by

I could likely find someone to do it for me but I'd rather just return it and get a new one. Ideally I would just reattach the ribbon cable to the old power button board but sadly, one of the pads is ripped right off the board.

by

Add a comment

Add your answer

Larry Jorgenson will be eternally grateful.
View Statistics:

Past 24 Hours: 3

Past 7 Days: 7

Past 30 Days: 38

All Time: 2,059