Fixing My ASUS RT-AC86U - Blown MT3125 IC

Symptom:

When I plugged it in, only the Eth4 LED lit up. Nothing else. No power light, no signs of booting. 

Research:

I found numerous posts indicating a common fault for this router: the MT3125 voltage regulator IC. So I proceeded to order the IC to attempt replacement. 

Repair:

I searched YouTube for videos on how to disassemble the router. I found this video helpful.

As expected, when I opened it up, there is a mini crater on the MT3125 IC:

When I pulled the faulty IC off, a few pads got ripped, but they seem to be NC(not connected) pads. I think 1 was ground as well, but there's a huge center ground plane so it doesn't really matter. The router was revived after replacing the IC. 

Ripped a few NC pads

I read on forums that the chip gets hot, and sure enough, when I use my thermal camera on it, it shows around 60-70 Celsius on boot. I stacked up a few pieces of my thermal pads so hopefully the heat can escape to the metal piece and not blow up so soon. 

Reaches 63 Celsius seconds after powering on

After adding thermal pad - hopefully it helps

Other useful links: 

Forum: https://www.snbforums.com/threads/asus-rt-ac86u-issue-dead-eth4-led-only.66442/

Logitech G603 Battery Drain Fix – How I Repaired Mine

Symptom

My Logitech G603 mouse started draining battery really quickly a while back. Initially, I thought it was perhaps a faulty battery, but after it went through a pair of fully charged AA batteries after a single week, I knew something was up.

I’ve found no cases online indicating the fix, all of them suggesting it to be a motherboard issue.

Upon powering it with my bench power supply, it draws 0.05A. I compared it with other wireless mice that I had, and they all only drew 0.01A.

Diagnosis

I turned on the mouse with my thermal camera and saw a component heating up.

Taken on my cheap mobile thermal camera

Marked A15, labelled Q10

The corresponding component is circled in the image above. It was hard to find the replacement part with no schematics and just a 'A15" marking on the transistor (excuse the ugly soldering, I desoldered it prior to test other similar transistors I had).

I tried searching on Taobao, and in the end found a matching part number: PJA3415

The chip marking when it arrived is different from the original. Because a connector is nearby and I didn’t want my hot air station to melt it, I soldered it using an iron instead. It’s kind of ugly, but it works.

Replacement component installed, marking "A5AE"

After replacing the component, the current draw on my power supply hovers between 0.00A and 0.01A. Battery drain fixed!

If you have a similar battery drain issue on your Logitech G603 mouse, you can perhaps try replacing this component to see if it fixes the issue.