5 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Costly or dangerous
50QN90A boot loop with blinking red light; owner reports chronic panel/power design defect
A 50-inch QE50QN90AATXTK owner describes the same boot-loop symptom (red light blinks twice, stays on black screen) after ~4 years, and states the authorized service and his own research attribute it to a chronic panel/power-supply design defect in the series.
What to check. This corroborates the boot-loop pattern across screen sizes in the series. The owner reports the panel replacement quote was near the price of a new TV, making out-of-warranty repair uneconomical.
QE55QN90AATXK enters boot loop after warranty; service quotes 35,750 TL panel replacement
Turkish owner of a 55-inch QE55QN90AATXK reports spontaneous boot loop shortly after warranty expiry; authorized service diagnosed 'panel arızası' (panel failure) without any inspection and quoted 35,750 TL — more than the TV's second-hand value.
What to check. A buyer should treat the QN90A panel as a known failure point after the warranty window. The repair quote is near the cost of a new TV, so an extended warranty or a different series is worth considering.
QN90A 85-inch owner reports bootloop after 3 years; another panel failure after 2.5 years
On Samsung's own Danish product page for the 85-inch QN90A, a German customer review reports a bootloop after 3 years, and another review reports the panel defective after 2.5 years with repair uneconomical. These are on the manufacturer's official page, so they are first-party customer reports.
What to check. This is independent corroboration from the manufacturer's own site, in the EU market, of the boot-loop and panel-failure pattern at 2.5–3 years.
QN90A CEC control with receiver stops working after firmware update, later resolves itself
An AVS Forum owner reports CEC (HDMI-CEC) control between the QN90A and an Onkyo receiver stopped working, possibly after a firmware update, but resolved itself without any changes. This is a transient connectivity annoyance, not a persistent defect.
What to check. CEC glitches after firmware updates are common and here self-resolved. Low concern for buyers; a firmware update or power cycle usually restores it.
QN90A from 2021 emits loud cracking noises from the TV after 2.5 years
A German owner of a 2021 QN90A reports loud cracking noises coming from the TV after ~2.5 years, with no picture faults. This is a low-severity cosmetic/mechanical concern, not a functional failure.
What to check. Cracking noises from the chassis are annoying but not a functional failure; the owner reports no picture issues. Low priority for a buyer.
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 Televisions catalog, version 0.1.1, under the CC-BY-SA-4.0 license.
