Question Have I killed the motherboard? ASUS K55a

Nov 2, 2019
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Hi Everyone,

Computer Specifications:
Asus K55A Laptop (uses Asus K55VD Motherboard)
Power: cable-mounted DC Jack (https://encrypted-tbn0.gstatic.com/...GmV7rf8QCOH3b7zFsRwQd3F3z3Fpq7phbwgosPRk3RD7b)

Disclaimer: I'm familiar with hardware components and replacement, but i'm new to soldering/electrical

So, this is my mothers laptop. We got it in 2013, so it's served it's purpose for quite a long time. One of the issues this laptop has always had is it burns through chargers, but it's also always had a loose DC port which has never helped the situation. The battery died about 2 years ago, which is fine, since it's usually always plugged in anyway, so we've never really replaced it. Recently, the charger started playing up again. After investigation, I found that the DC port (positive pin in the inside) was extremely loose and well worn.

I decided to pop down to the shop and pick up a PCB Male Connector (2.5mm). The bloke in there said it might work, but it might not. The laptop has a cable-mounted power-jack (see above picture). So, I cut off the original DC port, which left me with 6 wires. 3 positive, and 3 negative. it's a 6-pin.

Hooked it up to the new port, power was going through, but no response from the computer (no LEDs, nothing etc). About 4 hours later after playing around, it switched on with the new jack. After that, I thought all was fine, assembled the laptop back together, pushed the power button, and nothing. It's been like this since.

Along the way, I'd made a few sparks here and there on the DC Jack due to wires colliding etc.

But, 2 days later, there is still no power going through. I tried the old DC port again, but I cut the wiring to it so that it doesn't really have a solid connection, and since that port is broken, it's not a definite solution that points to the motherboard being fried.

I guess my question is, have I potentially blown-up the motherboard due to sparks etc? It seems as dead as a door nail. However, multimeter shows power from the charger, to the DC Jack, and even to the battery pins. Replaced the CMOS battery just in case, and tried "jump starting" the power button, but all to no avail.

Any help would be appreciated.
 
Yes sounds like the motherboard is bad or the charging port is still bad. If no power going to system and the battery is drained it won't start.

Sounds like you had the battery connected when you were installing the jack, with no power you should have no sparks. Why not replace the whole thing instead of cutting the wires? Or remove the whole connection instead of soldering it in the system? Could be several things that went wrong here.
 
Last edited:
Nov 2, 2019
2
0
10
Yes sounds like the motherboard is bad or the charging port is still bad. If no power going to system and the battery is drained it won't start.

Sounds like you had the battery connected when you were installing the jack, with no power you should have no sparks. Why not replace the whole thing instead of cutting the wires? Or remove the whole connection instead of soldering it in the system? Could be several things that went wrong here.

Thanks for the response!

The battery wasn't connected at the time. The battery doesn't hold charge anymore in any case. The motherboard is still receiving power throughout the circuit, but no LED's turn on, and no power when attempting to turn it on.

It's true, it could be the DC Port still, as since the battery doesn't work, amongst a different DC port, it could just be lacking power.

I live in New Zealand, we brought this laptop over with us when we moved from the UK, so sourcing parts for it is difficult (besides chargers). The only DC Port I could seem to find (including locations around the world) were from Aliexpress, which I wouldn't trust. I have a local IT technician attempting to source a new 6-pin DC connector for it, but no joy so far. The new port that was soldered, was not mounted as a PCB port (even though it's supposed to), I just used the 6 wires from the old port, to wire it to the new port.