The Tech Blog

Teardown & Repair: Asus Laptop

Posted under Repair, Teardown on December 28th, 2025 by Amaldev

Finally, I took the time to fix my ASUS TUF A15 which has been one of my daily-driver laptops. The wireless had been problematic for a long time, and I decided to do a hardware swap.

The problem was the WiFi/Bluetooth card, a MediaTek MT7921. It’s a bad chipset. You will find many reports online of WiFi disconnects and the laptop sometimes losing WiFi after waking from sleep. These modules are M.2 2230 A+E Key cards that plug into the laptop’s WiFi slot.

I decided to replace it with an Intel AX210 (WiFi 6E). The swap process is simple. Flip the laptop, remove the bottom cover, and lay the screws out on a flat surface in the same pattern they came out. Mostly, screw lengths differ, so process this prevents reassembly mistakes.

Now, the step most people skip. Always disconnect the battery before touching the card. When you slide an M.2 module in or out, it is easy to slip and short nearby pads with a tool. You do not want live power rails during that moment. On my unit, the WiFi card sits below the SSD, so it likely sees extra heat cycling (Probably a reason why it fails!). Pop the antenna connectors straight up, remove the single hold-down screw, swap the card, then reconnect the two antennas exactly as labelled. One would be the 2.4GHz and the other the 5GHz one.

Tweezers help for antenna routing and tiny connectors. Invest in a good pair. You have a normal one and a cross-action one. Cross action tweezers are great because they hold position without constant finger pressure. Most people don’t know of this.

Once the card is in, reassemble, do a quick dusting, then install the driver package and reboot. If you download drivers ahead of time, the first boot after the swap will be smooth.

The only note I want to give you is that, build the habit of debugging before you outsource to a shop. Stay curious, read service guides, and invest in a decent screw set at home. The repair shop should be your last option. Open things up and don’t be scared.

BTW: On most laptop WiFi cards, WiFi uses PCIe lanes, but Bluetooth is a separate USB connection on the same M.2 slot. Only WiFi is PCIe.

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Tech Explained: Bluetooth 6.2 SCI

Posted under Educational, Tech Explained on December 21st, 2025 by Amaldev

Last month, Bluetooth Core 6.2 made a change I have wanted for years. It solves a long-standing pain point in Bluetooth LE when you care about real-time response. Back when I was building low latency MIDI controllers at ACPAD, we were operating in the BLE 4.0 era. On that, I could move plenty of bits, but not shorter data faster. The main issue was the connection timing.

In BLE, a connected link wakes up in repeating connection events. The connection interval is the time between those events. Until 6.2, the minimum connection interval was 7.5 ms, which means your worst case packet can wait 7.5ms for the next connection, even before protocol overhead delays. For tight MIDI timing in real time instrument playing, this delay feels like a sound lag for professional musicians.

BLE 6.2 introduces Shorter Connection Intervals(SCI), pushing the minimum down to 0.375 ms when both devices support it. This means you can send small packets of data faster. In practice, that means you can get a polling rate over 1kHz. This is a big deal of HID devices like mouse. Gamers don’t use wireless BLE mouse for this exact reason. You will see a large boom in wireless BLE mouse and fall in the mouse with 2.4GHz USB dongles where this limit is not applicable.

Please note that your raw on-air speed is still based on the 2M LE PHY and that has not increased. Shorter intervals just reduce waiting time between opportunities to send small packets.

BTW, do not treat the smallest interval as a default setting. More transfers mean more battery loss. A better option is adaptive timing, meaning run a longer interval while idle, then negotiate a shorter one only during interaction, and return to a longer interval when activity stops. A 6.2 connection still starts at ≥7.5 ms and only then negotiates shorter intervals.

BLE 6.2 can mark some input packets as “flushable”. If packet loss conditions delays them, BLE can drop the old ones instead of sending them late. Good for mice or MIDI, as the late updates feel worse than a missed one.

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