I came across a shorted diode which needed replaced. It read 0 Ωs in both directions. The part number most significant appeared to be RB30. Above that was a number A34. The silk screen indicated a zener diode. I found a datasheet containing a list of zeners which contained the RB30 sequence inside all the part numbers. One device listed 3A4 as a stamp code. That particular diode had a zener voltage of 9.1 V which seemed appropriate for its location in the circuit, a charging circuit for an 11.1 V battery pack which powered the programming unit. I used a 9.1 V zener which I had on hand. That replacement along with a 330μf cap brought the unit back to life. I am unclear as to what the number referred to as a stamp code represents. A mnftr's inhouse code or maybe minimum mAs required? Really don't know.
Surface mount device. On the bottom of the case are embossed R6 and under those two, 0P. Also, on top of the device appears to be a circle with a line attached that runs to cathode marking. The letters inside the circle appear to read ON. I think it may well be a manufacture insignia. The circle is approximately 1/32" in diameter. Cathode is definitely attached to + side of solder pad.
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