You can adjust your Community Subscriptions in Settings
You can add Community Subscriptions in the search bar that says "Subscribe to more communities ..."
when the unit is switched on these eer codes are displayed in a sequence.
Here's the service manual
http://photos.medwrench.com/equipmentManuals/3890-3683.pdf
533 - Boot NVROM uninitialized error
After that error 533 appeared, the equipment did not turn on again?