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Name that Zener Diode

John949

Jun 5, 2017
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Jun 5, 2017
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I've blown a zener diode in my car CD Changer and having difficulty working out the breakdown voltage. It is a low wattage glass bead type (almost spherical) and appears to be marked with a 6 in the vertical orientation (right way up with the leads vertical) and a 2 orientated at 90 degrees to the 6. Is it 6.2V?

The design uses a single power transistor for regulation and this zener seems to set the output voltage. There is an IC that controls the motors that is rated at 12V so I'm tempted to put a 6.2 in and see what happens, but there are also some LSI chips on the board that are rated at 5.5 to 3.3V and if I blow those then the unit is scrap. There are some other zeners lurking on the board so maybe they drop the voltage further for the LSI chips.
 

shrtrnd

Jan 15, 2010
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NO guarantees, but it might help if you tell us the make and model number of your CD changer.
Someone here might be familiar with the model, or be able to access a schematic that might pin-point the diode.
 

John949

Jun 5, 2017
2
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Jun 5, 2017
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Well blow me down with feather, I've not had much success searching for circuit diagrams but I found a service manual with much useful information and a parts list here:

https://elektrotanya.com/alpine_chm-s620_sm.pdf/download.html

It's an Alpine CHM-S620 which is quite common (Mine's from a BMW E46)

The diode in question is an HZS9A2L. It would seem that the 6 is actually a 9 so it's an HZS-L series 9A2 with a zener voltage of 7.9 to 8.3V
 

shrtrnd

Jan 15, 2010
3,876
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We couldn't have done better ourselves.
Good work!
We're always here if you find yourself with new questions later.
 
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