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Notes on Don Quijote MUGA Stoic PC3, a Japanese (approx.) 200 USD low-end laptop PC

Don Quijote MUGA Stoic PC3

無我muga
the Buddhist doctrine of non-self, meaning that eternal and invariant self, or soul, is illusory
stoic
(adj.) determined not to complain or show your feelings, especially when something bad happens to you

This work is licensed under CC BY-SA 4.0.

No warranties are given by the author. Some procedures described in this work may void the warranty by the supplier and/or the manifacturer. Please read Section 5 – Disclaimer of Warranties and Limitation of Liability carefully.

Introduction

MUGA Stoic PC3 is the third generation product of a line of low-end laptop computers launched on 2020-08-28, by the Don Quijote discount chain store as a product under its private brand Jounetsu Kakaku (Passion Price).

Due to its poor performance and extensibility, I would not recommend this model in general. There are plenty of laptop PCs in used markets with higher performance, comparable prices and upgradable RAM and storage. You have been warned.

However, if you are stoic enough, you might find some fun from it. I hope I am.

I would like to strongly recommend to read Gotchas before doing risky operations.

Product information

The official product page: MUGAストイックPC3|家電|商品紹介|ドン・キホーテのプライベートブランド(PB)「情熱価格」|驚安の殿堂 ドン・キホーテ (in Japanese)

See Detailed Specifications.

Gotchas

Do not disable 512-byte sector emulation on the built-in eMMC.

While the built-in eMMC flash seems 4 KiB native and in fact you can disable 512-byte sector emulation with mmc disable 512B emulation <device>, don't do this.

If you do so, the vendor UEFI firmware slows down awfully its operation for unknown reasons and you can not boot from eMMC even if you clear UEFI boot entries and reinstall an OS into the device. In my case, it took nearly 11 minutes to load USB stick's GRUB, so does UEFI Setup.

I'd warn you once again: do not disable 512-byte sector emulation. Otherwise, you will experience an unrealistically long startup time a laptop computer sold in 2020.

Do not disable cache on the built-in eMMC.

You can the cache in the built-in eMMC flash by executing mmc cache disable <device>, but you must guess what is happen then. Don't do this, especially when you have disabled 512-byte sector emulation for some reasons.

Did you find interesting ways to brick the device?

Please leave a comment. Any recovery method would be highly appreciated, too. We need your brave soul and creativity!

Tips

  • To select the boot device, press F12 (Fn + F11) during startup.
  • To enter UEFI Setup, press F12 (Fn + F11) and then select Enter Setup.

Notes on the Internals

Too many things to write down here, but I will do one by one...

Detailed Specifications

It is possible that there is some differences between batches. If you find any difference on your board, please let me know using the comment form.

  • Model number: KNW14FHD3-SR
  • SoC: Intel Celeron N3350
  • RAM: NETSOL S5RG2G20CMS-MGCJ
    • Interface: LPDDR4, 2133 MT/s
    • Capacity: 4 GiB
    • Soldered: Yes
  • Internal Storage: UNIC2 UNMEN06GC2C31AS
    • Interface: eMMC 5.1
    • Capacity: 64 GB
      ... well, actually, it was 62,813,896,704 bytes (62.8 GB, or 58.5 GiB) on my laptop.
      The boot0, boot1 and rpmb partitions were 4 MB each, so they must not reserve 1.2 GB IMHO, but I am not sure.
    • Soldered: Yes
  • SD/MMC:
    • Type: microSD
    • Maximum Capacity: 128 GB (TODO: Confirm?)
    • Controller: Realtek RTS5170
  • UEFI ROM (?): GigaDevice GD25LB64CVIS (?)
    • Package: VSOP-8
    • Capacity: 8 MiB
  • EC ROM (?): GigaDevice GD25D10BTIG (?)
    • Package: SOP-8
    • Capacity: 128 KiB
  • Wireless NIC: Intel Dual Band Wireless-AC 3165
  • Super I/O: ITE IT8987E
  • Display: 14.1-inch 1920x1080 IPS
    • Model: Innolux N140HCA-EAC (according to DDC info.)
    • Touchscreen: No
  • Keyboard:
    • Layout: 83-key, JIS, QWERTY
    • Protocol: PS/2
  • Touchpad:
    • Protocol: PS/2
  • Webcam: Silicon Motion 300k Pixel Camera
    • Maximum Resolution: 640x480
    • Interface: USB
  • Audio:
    • HDA Codecs: Realtek ALC269
    • Speaker: 2x 1 W speakers
    • Mic: Available (Stereo?)
  • Other interfaces:
    • 2x USB 3.0 Standard-A
    • 1x HDMI Type-C (so-called mini HDMI)
    • 1x 3.5 mm in-and-out combo phone connector (CTIA TRRS?)
  • Battery
    • Model: U3285131PV-2S
    • 7.6 V, 5000 mAh, 38 Wh
    • Max voltage: 8.7 V
    • Rechargeable Li-Po
  • Power Supply:
    • Model: A241-1202000P
    • Input: 100-240 V AC, 50/60 Hz, 0.8 A
    • Output: 12.0 V DC, 2.0 A, 24.0 W
    • AC connector: JIS C 8303, ungrounded, parallel (globally known as US Type-A)
    • DC connector: Coaxial, center positive (TODO: Diameter?)
    • PSE: Yes, UL Japan 恵安株式会社 (PSE is the safety regulations for electrical appliances in Japan.)
  • Pre-installed OS: 64-bit Windows 10 Home in S mode, Build 18363
  • UEFI Firmware:
    • Vendor: American Megatrends Inc.
    • Version: AN12V 0.01 x64
    • Build date: 2020-05-13 16:25:00
    • TXE firmware version: 3.1.50.2222
    • EC version: 00.01
    • GOP version: 10.0.1030
    • Manufacturer: Keian(恵安)
    • CSM: No
    • Secure boot: Off by default
  • MIC Conformity Certification of Radio Equipment:
    • Certification Number: 201-200501
    • Category: Type Certification

Notes

  • Printing on some ICs is so poor-quality that I suspect that they are counterfeit. ROMs are especially doubtful.
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