I have a few queries regarding the burn in process as applicable to completed PCBs.

1. Is there any tangible benefit in doing the burn in at room temperatures ? Like for instance whenever we complete a unit it is left on power with a code that loops through the typical cycle. This has at times showed up faults like insufficient heatsinks for regulators that shut down; unduly heating ICs / transformers due to some problem ; noise related issues when the unit crashes due to insufficient filter arrangements.

Apart from above is it true that when fresh components are left powered they kind of bed-in and if no fault shows up in this phase of say 48 or 72 hours then the units will settle down reliably?

Though we are doing this as a matter of routine, I would be happy to hear from the experts if there are any guidelines for proper burn-in.

PS : A search on forum with Burn In as keywords returns 403 pages of burn in as applied to EPROMs and the like.

Thanks

Raghu