Sir tharindunn . . . . . . .
Ahhhhhhh so . . . . you have WANNIEN power supply.
Your zener identifier IS being a valid number string, but with none of their units falling in the lower 2V ( 2V1)
range or being as high as a 20 V value ( Their max voltage offering is being 18V.)
No idea on the other * diode. *
With this wattage of a power supply as this unit is being, the MAIN units SMPS and its components should be elsewhere and be using a controller and a set of large power FETS.
What I see this problem area as being, is the standby power supply section of the unit and that 8 pin . .less
pin #6 . . . as having its controller and internal power FET . . . ALL . . . contained within that case.
Pass us that I.C. s number to research, and you MIGHT just be lucky in the respect that this manufacturer
just copied the design of the IC manufacturers tried and true Application notes guidelines.
RATHER than having to be rushed and gambling on their own untried creation.
That data then might reveal the types and values of parts involved, by consulting those Application Notes.
My Viewing . . . . . via the re-referencing of your photo . . . .
Looks like the HOT AC line power comes in and routes up to the * UNK * power diode anode with a shunt
ceramic capacitor across the diode . It then creates a half wave DC supply to feed down to the right bottom
corners YELLOW and BLACK main raw DC supplys storage capacitor . It then feeds the 8 pin IC to create
the drive to the YELLOW KAPTON wrapped BLACK standby Switch Mode Power transformer up above .
Its secondary then outputs into the top, centrally located Full Wave Bridge rectifier block which then feeds over to the right, to the large BLUE main Low Voltage Supply storage capacitor.
(Check its voltage rating . . . . to therewith, evaluate an expected max. )
Some voltage from the secondary is routed to the right to what probably is a TL-431 adjustable zener reference and it drives the 817 family of optical isolater at the right side of the transformer.
This feedback loop provides load compensation correstion of the supplys regulated output voltage
Also, see if a foil path tracing of that main filter output does additionally reveal its feeding its output through an interim dropping resistor and ending up at the cathode of that mystery zener diode.
If so, then one might expect it to be either of the common used supply values of 12VDC or 5VDC.
That is also in acoordance as to that 12 V might then, ALSO, be further divided on down to a 5V value at another circuit tie in.
73's de Edd
