Unfamiliar Zener Diode

[pbinet]

I am a hobbyist electronics repairer and am working on a number of projects including a DVD player consumer SMPS 110V and I'm stuck with one component I can't identify that reads short. On the board it is identified as a zener diode and it connects in reverse between the control pin of the chip MIP2E4D and the secondary winding. The component length is 2.3mm. I have attached a photo and would appreciate any help

[harp]

Green green mean 55, maybe 5.5V? Aplication circuit maybe help...

[R_J]

Is the zener connected between Hot ground (S of ic) and (C of ic)? It is likely a 15v zener diode (panasonic MAZ4150) Is this power supply in a Sony dvd by chance?
Looks like the Control pin voltage is, Min 5.7v, Max 6.6v Typ 6.2v

The Blue on the lead is the Vz rating, brown first band, green second band, green third band

[pbinet]

Thanks RJ. It is a Sony DVD and that is the circuit. Can I use a standard 15V zener or do I have to source the MAZ4150?

Peter

[R_J]

I would just use a standard 1 watt zener, it seems to be more for spike protection than anything, I would also replace the two electrolytics in that circuit.

[pbinet]

Thanks RJ. Both caps read OK with reasonable ESR but I'll change them as you suggest.

Peter

[stj]

did you check the diode off the board?

[pbinet]

Thanks to all! My first time posting in this forum and I am well impressed with all the responses. Thank you all. I have followed RJ's advice and the high voltage supply is working. There are ten low voltage supplies four of which read differently than posted on the board so I will now work on tracing/replacing the components in those lines.

Regards,

Peter

[R_J]

The markings printed on the board may be wrong for this model dvd, the power supply is made by mitsumi for many different products, maybe it is time to post the model number of the dvd player or look online for a service manual.
Does the dvd player work? which voltages are wrong? some of the voltages are switched and only present when the player is on.

[pbinet]

R J Yes I should have posted the model number it is Sony DVD player model NC875V. I now have the service manual with schematic from ElectroTanya. The low voltages are on pin 1 reads 5.45V should be 8V, pin 5 reads 3.5V should be 5V, pin 5 reads 3.0V should be 3.3V, and pin 6 reads 3.5V should read 5V. Two components on the board I don't recognise are green smd capacitor looking components which the schematic marks as P311 and P312. One of them P311 doesn't read and no voltage is flowing from it into the two diodes D315 and D317 in series.

[pbinet]

Apologies as I noticed I uploaded the full manual instead of just the power block schematic. I have now attached the schematic and a photo of the component P312. I have already removed P311 from the board. Two issues with these components in the circuit are P311 blocked all voltage and P312 drops 1.5 volts. The block diagram elsewhere in the manual shows these as connectors. I don't know if there is something special about these components or if I could just replace them with zero ohm resistors?

[R_J]

They appear to be smd fuses (different sony model) are there any letters on them?

[pbinet]

Yes the letter Z (photo attached). I did temporarily put in zero ohm resistors just to check and now have all working voltages.

[R_J]

Looks like N which would be 2 amp likely 32v. Good to hear it is working.

[pbinet]

Thanks RJ. I'll source those and finish the job when they arrive. I really appreciate your help.

Peter