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Old 9th January 2005, 10:04 PM   #11
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Originally posted by Nisbeth

The Zener is there to protect the amplifier module if the regulator fails. Leave it be!

That makes sense to me.

Anyway, I disconnected one leg of the zener and everything worked again. So that proved the zener was responsible for the short.

Now the most difficult part will probably be to find a "shop" where they sell single smd zeners
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Old 9th January 2005, 10:32 PM   #12
VS is offline VS  Portugal
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With some careful while soldering you may replace the SMD zener with a regular one (smallest package type, 400-500mW)...donít waist your time! Good luck!
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Old 10th January 2005, 04:22 AM   #13
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Simple ohms test across the 12volts should have saved lot of trouble.

Gajanan Phadte
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Old 10th January 2005, 07:00 AM   #14
raypsi is offline raypsi  United States
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Default zener really?

We all want to be correct. It's really an avalanche diode. They haven't made zeners for 20 years. Oh they may still call them zeners but the truth is they aren't zeners. Zeners have a gradual knee. Avalanche diodes have a sharp knee. Guess which one is cheaper to make? That is why nobody will make a zener any more, they just can't compete. Avalanche diodes make great overvoltage protectors and will short in a fempto second, to protect your circuit.
semper fi
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Old 12th January 2005, 11:15 AM   #15
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Default Re: zener really?

Originally posted by raypsi
. Avalanche diodes make great overvoltage protectors and will short in a fempto second, to protect your circuit.

Unfortunately still not quick enough, one of the amplifier modules blew an opamp (at least, with visible damage).
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Old 6th March 2013, 11:20 PM   #16
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Default TZM15V

Good evening, which diode should I use in place of tzm15v?

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Old 7th March 2013, 02:55 AM   #17
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Originally Posted by ericpeters View Post
No The regulator is ok, I lifted the output leg and the voltage was back.
Not necessarily OK. What you KNOW is that the regulator puts out 12V with no load but have no idea what it does under load. I'd take an Ohm meter to the 12V bus now that the regulator is disconnected. Tantalums and ceramics sometimes turn into dead shorts. If you have a shorted device - passive or semiconductor - the meter will show it.

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