Samsung Galaxy S25 Ultra troubleshooting

Published specification

What is true of this model and changes how you fix it

These are the properties that decide which procedure applies. Each is read from the manufacturer’s own published figures for this model, not carried over from a sibling that shares its retail name.

Display

174.2mm (6.9" full rectangle) / 172.2mm (6.8" rounded corners), 3120 x 1440 (Quad HD+), Dynamic AMOLED 2X, up to 120 Hz. Samsung quotes two figures for screen size — the full rectangle and the rounded-corner measurement — which is why this phone is listed at two different sizes in different places and neither is wrong.

Refresh rate

Up to 120 Hz adaptive. A high refresh rate is one of the larger discretionary battery costs on this phone: it is genuinely smoother and it genuinely costs runtime, which is why battery complaints on this model are worth checking against the refresh-rate setting before anything else.

Panel

Dynamic AMOLED 2X. This is an AMOLED panel, so dark mode reduces consumption for real — black pixels are switched off rather than backlit — and a static bright element left on screen for very long periods is the one wear risk this panel type has.

Rear cameras

200.0 MP + 50.0 MP + 50.0 MP + 10.0 MP. A 200-megapixel main sensor produces very large files at full resolution, and it is the reason this model fills storage faster than almost anything else in the range. Samsung defaults to a binned lower-resolution output for exactly that reason — a storage complaint here is often a capture-resolution setting.

Zoom

Optical Zoom 3x and 5x, Optical quality Zoom 2x and 10x (Enabled by Adaptive Pixel sensor). Zoom range is the practical difference between models in this line. A close-up that will not focus at the long end is normally the telephoto's minimum focus distance rather than a fault — taking the same shot at 1x confirms it in seconds.

Video

UHD 8K (7680 x 4320)@30fps. Resolution and frame rate dominate how quickly video fills storage and how hard the phone works thermally — sustained 8K recording is the single most common reason a Galaxy camera stops mid-take and warns about temperature.

Memory and storage

12GB RAM with a 256GB storage tier. RAM matters directly to one symptom: apps reloading when you switch back to them is memory pressure rather than a crash, and it is more likely on the lower-RAM configurations.

SIM

SIM 1 + SIM 2 / SIM 1 + eSIM / Dual eSIM. Three combinations are supported, and the default line for calls, for messages and for cellular data are three separate settings — crossing them produces calls arriving on one number while data or messages use another, with almost no indication that anything is wrong.

Wi-Fi

802.11a/b/g/n/ac/ax/be 2.4GHz+5GHz+6GHz, EHT320, MIMO, 4096-QAM. This is Wi-Fi 7 hardware with 6 GHz support, so it can use bands an older phone on the same network cannot — which is worth knowing before concluding the router is at fault when one device performs differently from another.

Bluetooth

Bluetooth v5.4. Version affects range, reconnection behaviour and which accessory features are available — a newer accessory paired here operates at this version's capabilities rather than failing, which is regularly mistaken for a pairing fault.

Connector

USB Type-C. Note that a USB-C cable which fits is not necessarily rated for this phone's charging speed: USB-C carries several power profiles, and a data-oriented cable charges slowly or intermittently while seating perfectly.

Samsung's own specification

Samsung publishes the full specification for this model at samsung.com/uk/smartphones/galaxy-s25-ultra/specs/. Where any figure above matters to a decision, that page is the authority and this one is not.

Biometric

An in-display fingerprint reader, which looks through the screen. A thick or incompatible screen protector genuinely interferes with it, which is why unlock reliability often changes the day a protector is fitted rather than gradually.

Modem

5G capable. In marginal 5G coverage the phone hands repeatedly between 5G and LTE, which costs more battery and generates more heat than settling on either — so the preferred-network setting is a real diagnostic lever rather than a preference.

Charging

Supports wireless charging. Coil alignment is tighter than it looks and a thick case, a metal plate or a card in the case defeats it entirely — so wireless charging failing while cable charging works is usually the case rather than the phone.

Water resistance

Rated water resistant, which is not waterproof and which degrades with age, drops and seal disturbance. The rating covers incidental exposure; it is not a guarantee, and moisture-detection warnings are deliberately conservative and can persist after the port feels dry.

Platform

Android, with a manufacturer interface layer over it. Battery optimisation and background-execution restrictions are applied per app and are far more aggressive than on iOS — which is why 'set this app to unrestricted' is a real fix here and has no equivalent elsewhere.

Where these figures were read. samsung.com/uk/smartphones/galaxy-s25-ultra/specs/ (Galaxy S25 Ultra — Specs), read 2026-08-28

Manufacturer support for this product line. Samsung Support — Mobile device support. Official Galaxy model manuals, diagnostics, updates and repair support.