Common Issues

The 2 series is generally well-received by the community and are many peoples' favorites, despite their faulty little noggins.
Do not attempt AIBO repair without knowing what you are doing. These dogs have proprietary parts and are extremely fragile. Even seasoned AIBO veterinarians have had repair failures. We are not liable if your dog breaks.

DHS, PAS, TAS (Droopy Head Syndrome, Pan Axis Syndrome, Tilt Axis Syndrome)
By this point, all unrepaired non-supercore dogs have or are developing at least one of these syndromes.
Dogs afflicted with DHS, PAS, and/or TAS are unable to move their head on the afflicted axis due to the faulty clutch slipping.
Developing syndromes still allow for movement, but may get stuck at the extremes of the axis - ie TAS dogs needing their head manually tilted back to its default position during boot so it can tilt in the opposite direction.
When powered off, afflicted axes have little to no resistance and don't make any mechanical sound when moved manually. When powered on, the afflicted axes will loudly whir as it attempts to move the head into the correct spot.
Developing DHS/PAS/TAS will get worse over time, with or without use.
Supercore models had the pitch axis fixed, resulting in immunity to DHS. PAS and TAS are still possible, but less likely.
This will need to be pinned by a professional. Do not attempt this repair yourself. You will break your dog.

Jitters
A buildup of dust in the dog's potentiometers causes them to send inaccurate readings. This makes the dog try to fix it repeatedly, resulting in the affected part "jittering" or shaking.
Minor jitters can be cleared with runtime and physical therapy (manual movement of the afflicted part), while major jitters may require disassembly to clean the potentiometer directly.

Missing ears & tail are common, but do not affect the functionality of the dog and are solely cosmetic. 3D-printable replacements do exist if this bothers you.