[TechAssist] Re: Zener diode test

  • From: Jim Myers <jr.myers@xxxxxxxxxxx>
  • To: techassist@xxxxxxxxxxxxx
  • Date: Thu, 09 Jun 2005 16:55:39 -0500

Do you need help with a problem? All I have seen so far is questions 
about how to test a zener. If you want to post a model number and 
symptom and what you know so far maybe someone can help.


********************************
Since 1972                     *
Jim Myers                      *
Telrad Electronics             *
Fort Wayne Indiana             *
********************************


Paul wrote:
> I don't think they are causing problems either after checking for go or no 
> go. The meters both have relativly new batteries so would be surprised if 
> that were the cause, but it might be worth a try anyway. This whole thing 
> came about because this board is NLA per Andrews, where I buy most of my 
> parts. Another surprise for a 2 year old 32"Sony. However the unhappy 
> customer  called Sony and they told the customer that is was available under 
> a new number,and further that if they had called an asc he would have known 
> that. Not sure how the asc would have information that the parts house 
> dosen't? So I decided I would repair the board and that is where this all 
> started. Going through the board ran across these odd diodes. The tact 
> switches on this board cost more than the whole board ready to go.
>                                                                  Paul 
> Jim Myers <jr.myers@xxxxxxxxxxx> wrote:
> Look up MTZJ-T-77- in NTE and you'll find a fair selection of various 
> zeners, the first few on the list, up to 10 volts require a test current 
> of 20ma and the rest require only 9.5ma or less. Maybe a new battery in 
> your meter WOULD make a difference. In any case if they are used as a 
> protection device on the A/V inputs and are not shorted they are 
> probably not causing any problems.
> 
> 
> ********************************
> Since 1972 *
> Jim Myers *
> Telrad Electronics *
> Fort Wayne Indiana *
> ********************************
> 
> 
> Paul wrote:
> 
>>Yes, I agree. They appear to be just 1/2w Zeners, although very small glass 
>>cases. I measured a 9.1v, 1w that I had in stock and it measured fine on both 
>>meters. Interesting though, I checked to see if they would zener and they do 
>>9.4v. They still don't front to back. How do you figure that? These are in a 
>>2 year old set and are used in the A/V input circuit apparently as protect. 
>>Paul
>>
>>Jerome Silverman wrote: 
>>Sounds like plain vanilla 9.1 volt zeners. But to answer your question, some
>>"zeners" are actually ICs and some have one or more forward biased diodes in
>>series with the zener element and some may consist of two or more zener
>>elements in series.
>>Jerry Silverman
>>Greentron Inc
>>4 Newland Ave Greenville SC 29609
>>Fax/Phone 864 232 3889
>>greentron@xxxxxxx
>>
>>----- Original Message ----- 
>>From: "Paul" 
>>To: 
>>Sent: Wednesday, June 08, 2005 9:44 PM
>>Subject: [TechAssist] Zener diode test
>>
>>
>>
>>
>>>Are there zener diodes that cannot be measured? I have 4 Sony zeners P/N
>>
>>MTZJ-T-77-9.1B on a board. They do not cross and I am guessing they are 9.1v
>>zeners. They all are either open or they do not measure. Have lifted one end
>>and measured with two different meters,Beckman and a Fluke still no reading.
>>Can't believe all 4 are open.
>>
>>
>>>Paul
>>>
>>>Paul ,B
>>>Central TV&Video
>>>911W Grand Ave
>>>Grover Beach Ca.
>>>(805)481-8084
>>>
>>>--------------------------------------------------------------------------
>>
>>---
>>
>>
>>>This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
>>>Lost Password: http://www.tech-assist.org and select "Login Problems?".
>>>Appliance Repair List:
>>
>>http://www.tech-assist.org/secure/tip/chatjoin.htm#app
>>
>>
>>>Email Archives: //www.freelists.org/archives/techassist/
>>
>>
>>-----------------------------------------------------------------------------
>>This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
>>Lost Password: http://www.tech-assist.org and select "Login Problems?".
>>Appliance Repair List: http://www.tech-assist.org/secure/tip/chatjoin.htm#app
>>Email Archives: //www.freelists.org/archives/techassist/
>>
>>
>>
>>
>>
>>Paul ,B
>>Central TV&Video
>>911W Grand Ave
>>Grover Beach Ca.
>>(805)481-8084
>>
>>-----------------------------------------------------------------------------
>>This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
>>Lost Password: http://www.tech-assist.org and select "Login Problems?".
>>Appliance Repair List: http://www.tech-assist.org/secure/tip/chatjoin.htm#app
>>Email Archives: //www.freelists.org/archives/techassist/
>>
> 
> -----------------------------------------------------------------------------
> This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
> Lost Password: http://www.tech-assist.org and select "Login Problems?".
> Appliance Repair List: http://www.tech-assist.org/secure/tip/chatjoin.htm#app
> Email Archives: //www.freelists.org/archives/techassist/
> 
> 
> 
> Paul ,B
> Central TV&Video
> 911W Grand Ave
> Grover Beach Ca.
> (805)481-8084
> 
> -----------------------------------------------------------------------------
> This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
> Lost Password: http://www.tech-assist.org  and select "Login Problems?".
> Appliance Repair List: http://www.tech-assist.org/secure/tip/chatjoin.htm#app
> Email Archives: //www.freelists.org/archives/techassist/
> 
-----------------------------------------------------------------------------
This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
Lost Password: http://www.tech-assist.org  and select "Login Problems?".
Appliance Repair List: http://www.tech-assist.org/secure/tip/chatjoin.htm#app
Email Archives: //www.freelists.org/archives/techassist/

Other related posts: