Sony Xperia 5 II Repair Help: Learn How to Fix It Yourself.

6.1 in 1080×2520 OLED panel, HDR10+, HDR BT.2020, 10 bit, 120Hz, 449 ppi, 80.9% screen to body ratio, 600 nits max brightness
Protection: Corning Gorilla Glass 6

Ports:

3.5mm Jack (Top)
USB Type C 3.1 port (5Gbps) (Bottom)
UART (via SD Card, 1.8v)
SD Card Slot (MicroSD, up to 1TB)

Audio:

Audio Codec/DAC: Qualcomm Aqstic WCD9385, 24 Bit/192kHz (32 Bit/384kHz unofficially)
Amplifier (Speaker): 2x Cirrus Logic CS35L41

Audio Features:

Dolby Atmos (E-AC3 JOC/AC4)
360 Reality Audio
DSEE Ultimate
Dynamic Vibration
Intelligent Wind Filter
Hi-Res Audio (up to 32 Bit/384kHz)

Battery/Power:

4,000mAh Li-Polymer Battery (3,860mAh Typical/Min)
Charging Speed: PD 3.0 21w, 50% in 30 min advertised

Camera (Back):

12 MP, f/1.7, 24mm (wide), 1/1.7", 1.8µm, dual pixel PDAF, OIS
12 MP, f/2.4, 70mm (telephoto), 1/3.4", 1.0µm, PDAF, 3x optical zoom, OIS
12 MP, f/2.2, 124˚, 16mm (ultrawide), 1/2.55", dual pixel PDAF
Zeiss optics, color spectrum sensor, LED flash, panorama, HDR, eye tracking

Camera (Front):

8 MP Wide, f/2.0, 24mm (wide), 1/4.0", 1.12µm

Video (Back):

4K@24/30/60/120fps HDR (Hybrid Log Gamma), 1080p, 720p

Video (Front):

1080p 30FPS

Color options:

Black, Grey, Blue, Pink, Purple (Limited Edition)

Networks/Communications:

Cellular: GSM/HSPA/LTE/5G
SIM: 2x Nano SIM (shared by SD slot) (Excluding Japanese models), 1x Nano SIM (Japanese models)
Modem: Qualcomm Snapdragon X55
Bands (2G): GSM 850, GSM 1900
Bands (3G): HSDPA 800 / 850 / 900 / 1700(AWS) / 1900 / 2100
Bands (4G LTE): 1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 19, 20, 25, 26, 28, 29, 32, 34, 38, 39, 40, 41, 46, 48, 66*
Bands (5G NR): 1, 3, 8, 28, 77, 78 SA/NSA*
WLAN: Wi-Fi 802.11 a/b/g/n/ac/6, dual-band, Wi-Fi Direct, DLNA
Hotspot: Wi-Fi 802.11 a/b/g/n/ac/6*
Bluetooth: 5.1, A2DP, aptX HD, LE
Positioning: GPS, GLONASS, BDS, GALILEO, QZSS
NFC: Yes
NFC-F/Osaifu-Keitai/FeliCa: Yes, Japanese Models only*
FM Radio: Yes, Japanese Models only

Features:

Water Resistance: IP65/IP68 dust tight and water resistant (low pressure water jets; immersible up to 1.5m for 30 min)
Sensors: Fingerprint (side-mounted), accelerometer, gyro, proximity, barometer, compass
Bootloader Unlock (all variants excluding Japanese carrier models)
Physical Camera Shutter
Assistant Button (can be remapped)

Notes:

Some earlier Xperia 5 II and Xperia 5 III devices had particularly bad "Lightsaber" issues. The OLED screen would fail with a permanent line, this is due to them using Samsung display panels, which had a design flaw with the ribbon connector. The only solution is to replace the OLED panel. Heat may exacerbate how fast the device gets the OLED line of death.
Japanese models have major compatibility issues with US cellular networks, but will work partially on T-Mobile USA, however some features like VoLTE do not work out of the box. To enable VoLTE, you will need to re-flash with Xperia Companion. 5G is also not supported on any variant in the US. Tested with SOG02 variant
The UART Port is located in the SD Card Slot. Do NOT use 3.3v or 5v, it is strictly 1.8v TTL. Using 3.3v or higher will permanently damage the device.
5G NR is only supported by Global and Asia variants, will not function at all in the United States
While the device has those 4G LTE bands, not all of them are available everywhere. Notably, the SOG02 has a very limited band selection, on T-Mobile US, it can only use Band 4 AWS-1. This leads to extremely poor connectivity, sometimes to the point that you cannot connect at all.
Hotspot on most models can do 5GHz, but on the Japanese models weirdly, they are limited to 2.4GHz only.
Only Japanese variants have NFC-F/Osaifu-Keitai/FeliCa because this is a hardware feature, which isn't included on non Japanese variants.
The fingerprint scanner on some Xperia variants, particularly the 1/5 II, 1 III/5III are prone to failure.
The amplifier used for the headphone jack in the 1 and 5 II is considered weak, which can result in low volume for some IEMs and earbuds, fixed in the 1 III and 5 III

Variants: