3 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Costly or dangerous
Steam Deck LCD board-level fault: black display, dead controls, fan at 0 RPM, CPU stuck at 400 MHz
An owner describes a sudden hardware failure (out of sleep) where the internal display goes black, controls die, the fan reports fault, and the CPU is stuck at 400 MHz; a fresh SteamOS reimage does not fix it, pointing to a board-level fault rather than software.
What to check. This is a sudden, non-user-caused hardware failure that survives a full OS reimage. If buying second-hand, ask whether the unit has ever shown this symptom; it is not fixable by software and may require board repair.
Steam Deck LCD random shutdowns and high GPU temps after BIOS update
An owner reports the LCD model became unstable after a BIOS update, with random shutdowns, NVMe-style boot errors, and high GPU temperatures.
What to check. If you buy an LCD Deck, be aware a BIOS update can trigger random shutdowns and thermal spikes; owners report rolling back the BIOS as the fix. Verify the unit's BIOS/SteamOS version before purchase.
Valve phasing out original spare parts and batteries for the Steam Deck LCD
Reports that Valve is phasing out original LCD spare parts via iFixit, with batteries out of stock and low likelihood of restock; OLED parts remain available.
What to check. For an EU buyer, the LCD model's repairability is shrinking: original batteries are being discontinued, so a worn battery may not be replaceable with an official part. Factor this into the purchase decision.
These reports come from the pages linked under each item: owner forums, repair guides and workshops. They are not a diagnosis of any one unit, and a careful check of the one you are buying still applies.
Text from the Kriko Gaming consoles catalog, version 0.1.1, under the CC-BY-SA-4.0 license.
