Sony Diode St02d-140

[tech2014]

It has the marking T2D98. It is open circuit. Does anyone know where I can find this part or is there a replacement I can use.
thanks

[ReeceyBurger123]

Re: Sony Diode St02d-140

Ebay, or search google. You sure its O/C normally these when they fail will go S/C but it can happen ?

[tech2014]

Re: Sony Diode St02d-140

I found the data sheet for it. I don't think its open circuit going by the symbol/pinout from the data sheet. Measuring across it measures from anode to anode.

[Electronic Handyman]

Re: Sony Diode St02d-140

Best way to check that part is de-solder one end from the board or totally remove it.Mouser.com probably has it cheaper then what i found on ebay.

[R_J]

Re: Sony Diode St02d-140

It's a clamping diode, it's going to check open, it conducts when the voltage accross it exceeds the breakdown voltage of:
Min. 130
typ. 145
Max. 160
when its in circuit working it probably has around 130 -145 volts accros it.
Clamping at a maximum of 200 volts . at that point it probably fully conducts acting like a short
https://cdn.badcaps-static.com/pdfs/...cf2b63802a.pdf

[redwire]

Re: Sony Diode St02d-140

Shindengen ST02D-140 pdf
It looks like a 145V 200W unidirectional TVS with a 600V series reverse diode. I haven't seen that combination offered by other companies. Used for snubber clamps.

I would put a P4KE150A or 1.5KE150A and a UF4005 in series to make it out of two parts.

It should check out, start conducting at 145V but no 0.7V (open) in the reverse direction. These probably fail short.

[budm]

Re: Sony Diode St02d-140

Can you tell us what kind of unit you are working on and the location where this Snubber/Clamping diode being used?

[tech2014]

Re: Sony Diode St02d-140

Can you tell us what kind of unit you are working on and the location where this Snubber/Clamping diode being used?

It for a Sony STR-KS360 a/v receiver. The fault is when you try and power it on, the unit shuts down. I get all my voltages for a few seconds then they drop back. Checked all voltage regulators and all are good. I get no voltage coming out of IC921(see screenshot). I decided to remove the diodes to test and D921 looked open, but now I know its fine.

[budm]

Re: Sony Diode St02d-140

So what DCV do you on all of the pins of that SMPS IC921? All 0 Volt?
What GND are you using when test the Voltage on that IC?

[tech2014]

Re: Sony Diode St02d-140

So what DCV do you on all of the pins of that SMPS IC921? All 0 Volt?
What GND are you using when test the Voltage on that IC?

Chassis ground

[budm]

Re: Sony Diode St02d-140

Chassis ground

You are working in the primary side so you cannot use chassis GND as the GND ref. for your meter, you can use chassis GND as the GND ref for cold side of the circuit.
Look at the circuit and see how the GND point of that circuit is connected to, does the GND point of that circuit show 0 Ohm to the chassis?
You should know that by now since you have been fixing many TVs.

[tech2014]

Re: Sony Diode St02d-140

You are working in the primary side so you cannot use chassis GND as the GND ref. for your meter, you can use chassis GND as the GND ref for cold side of the circuit.
Look at the circuit and see how the GND point of that circuit is connected to, does the GND point of that circuit show 0 Ohm to the chassis?
You should know that by now since you have been fixing many TVs.

You are right. Not used to working on audio equipment with SMPS, usually they have a linear power supply. I will take a look at the schematic.

I really appreciate the help budm.

[Longbow]

Re: Sony Diode St02d-140

No, this is a temperature stabilized voltage reference. Obviously it won't test like a regular diode and the only real way to test it is to add a resistor in series with it and put it on a d.c power supply. I'll bet the voltage will come out to be around 5.6 volts, which is the zener voltage with the best dynamic resistance figure. The schematic should show you what the actual voltage would be - and, you can reproduce the exact thing with a zener of correct value and a 1n4148 tied together thermally. My guess is that the part is not faulty anyway.

[budm]

Re: Sony Diode St02d-140

It is snubber/clamping diode. 1N4148 and 5.6V Zener is not going to handle high Voltage spike and current from the primary winding fed by 300V power source.

[R_J]

Re: Sony Diode St02d-140

The voltage for ic921 is supplied from the main bridge through jumper wires jw981/982 through r929 2.2 ohm, if its open I suspect the ic921 is bad, also check R927 .82 ohmif its ok The first voltage I would check is the +31 on CN904, that feeds the output ic's if its not there, disconect the plug and see if it comes up. I can't say for sure but my moneys on one of those output ic's being shorted, I did see that problemon earlier models

[Chungalin]

Re: Sony Diode St02d-140

Shindengen ST02D and ST03D family of Power Clampers cause a lot of confusion because they're sometimes drawn as normal diodes on schematics and they can't be tested with DMM under diode mode. They exhibit open in both ways.

On the other hand, to date I've been unable to externally differentiate its voltage rating. ST02D and ST03D can be 82, 140, 170 or 200V, but all are marked as T2D and T3D, respectively. Datasheet doesn't help. Some people say that the other two smaller digits following the main marking have something to do, but I don't agree.

My theory is that they can be distinguished by marking color. I have some of them that marking lettering is dark red, and others is yellow. This has to mean something. Or maybe not. I tried to contact Shindengen with this question but I obtained no response.

ST02D and ST03D can be found in Sony DVD power supplies, usually as a companion of Panasonic MIP2E3DMY, MIP3E3SMY, MIP3E4MY switching regulators. I've seen them too in Vorwerk Thermomix TM31.

[Chungalin]

Re: Sony Diode St02d-140

Another Shindengen trouble: how to distinguish between D3S4M and D3S6M Schottky diodes? Both have marking D3S. The other two digits are datecode, nothing to do with max voltage. I have two marked in blue ink, and another two in white ink. I think that’s the key, but still I’m unable to find any official doc that confirms this color coding.

More: I have a rectifier diode marked as 3LU in violet ink. This can be a S3L20U or a S3L40U.

I can understand this kind of ambiguity in SMD components, but not in larger components where there’s enough surface to write full component name.

[Chungalin]

Re: Sony Diode St02d-140

I attach datasheet for Shindengen S3V60. This is the first clear reference to marking color that I’ve found. Blue: S3V (S3V60), red: S3V (S3V20).

Others have to follow similar convention, but I’m just unable to find where it’s documented.

[Wisdom]

Re: Sony Diode St02d-140

Guys, I know my question should be an off-toppic, but, since I can not post an new thread, I will ask here about the diode T2D98.

(Google bring me here after search for this diode)

I have an dead powersupply from an HP 8000 Elite SFF with this diode dead, reading this thread if I get right the idea, I should replace it with St02d-140 is it?

Note: I am willing order on mouser.

[Chungalin]

Re: Sony Diode St02d-140

What means that "this diode is dead"? If it’s not shorted, it’s probably not dead. Forget about the ending "98" (in smaller lettering), it’s a date code, not anything related to part number. Which color is the marking? You should replace it with another ST02D of the same color, because I still don’t have any info on how to identify voltage rating by marking color.