Re: Isn't TO-2015 a power transistor package?
I can't remember if they were TO-3 or another large metal power package of the era, but as I recall the technicians who serviced the CU Titan computer used to identify blown power supplies by tapping the transistor cases and listening for the rattle of a large germanium die that had fallen off.
On another occasion I discovered that an "engineer" at one company I worked for had built a large custom DC power supply using paralleled 2N3055 - which some of you may remember - but with neither ultrafast fuses nor any proper means for ensuring correct current sharing in the output stage. I discovered this when the supply went titsup*, and two cases had arced through leaving large holes while a third one was just in the process of melting when the power was tripped. At least you could see what was happening.
*transistor internal transfer of silicon by unexpected plasma.