Sir bushtech . . . . .
Moving on down to your situation . . . .
" Mine is a SM 53 6. "
Now, I could only suspect it being the same on THAT part needed.
With the 53 being the key numbers and being unsure of the end 6 aspect.
IF your unit is not testing out as being SHORTED then use the same advice in the use of a higher DC voltage . . .being current limited by a series 1 meg resistor in line with that voltage source.
That then provides a means of non destructive testing upon that device and you being able to see the area that the voltage clamping effect starts with that diode.
(Test and swap around both ends, as you might have yourself a bidirectional unit . . .versus a unidirectional one.)
You just monitor the DC voltage from ground to the resistor lead of the 1 meg resistor, that is being away from the power supply.
As you increase the supply voltage and swing the diode in with one end grounded and the other end making temporary contact to the voltage measuring point , you will see the diodes engaging effect of progressively dropping that test voltage level, as it is gradually being increased.
OR its having NO effect on the test voltage . . . . if the diode is then being swung away from that test connection node to a non contacting position..
BTW . . . . .Peanut Gallery Audience: . . . .et al
THIS is the same procedure that I use on MYSTERY transistors that I have found in the deep dark bottom depths of my junque box.
In testing from C-E for bipolar transistors, I am then able to ascertain the initial onsetting VCBO avalanche voltage threshold of that tested transistor..
I then duly deduct 25V from that value for higher voltages if being on up in the hundreds of volts or if being a low voltage unit, only 5 V is deducted.
DIODES:
If being a ZENER, you just read out that voltage, but for a truer reading you would need to up the test current level.
BUT if you are testing a silicon family diode, and you see voltage drop onsetting . . . .you either have yourself a Zener diode if it remains stable . . . . .OR . . .you have just found yourself the PIV threshold of that diode.
Just underate it, as was being done on the transistors, to keep well below that critical voltage threshold.
In my particular case, my variable voltage supply source . . . .up to 500VDC . . . . is being and old EICO resistance capacitance bridge, being used in its leakage voltage test position.
That occasional use of that unit seems to keep its internal power supply electrolytics in a healthy state of reformation.
FACTOID:
Do you "recognize" that I have found some 1N4007's that do not show an avalanching onset, until getting on up into the 1700-2000 VDC region ? Lower 1N4000 series can be just as spread out !
(Thats having to use a 3KVDC power supply source made by Varo . . .being run by a single " D " cell . . . that was originally used with a VN era sniper nightscope.)
In my researching of GI / GS . . .the diode and transistor guys . . .I went as far back as the last engineering catalog that I had from them, and even in it, the exacting "53" spec was being non related .
So I would say to go with the SMAJ54A in the parts list above, if your avalanche testing above does not confirm the unit to be working and being good.
If anyone needs that last GI / GS product catalog. . . .issued just before their being absorbed by Vishay . . . for their really-searching, it is available in my electronics reference library at Scrib-D as:
GENERAL INSTRUMENT / SEMICONDUCTOR PRODUCT CATALOG:
https://www.scribd.com/user/8625470/Edd-Whatley
Some other of my posted technical info + schematics are here:
http://s391.photobucket.com/user/eddwhatley/library/?sort=3&page=1
Thasssssit . . . . . . .
73's de Edd
