[TenTec] How Much Damage From Reversed Polarity?

[doc]

I have lifted the damaged zener, no effect.

I am going to replace the transistor with a 2N2222
per the recommendation of Tentec.

Will advise later in the week when I again have a few
minutes to work on the rig.

Thanks to all for the helpful advise and encouragement!

73, doc kd4e

Bert Braun, DD5XL wrote:
> doc schrieb:
> 
>> There is no visible damage to anything that I can
>> see on the little circuit board to which the power
>> connector is soldered.  No smell of something
>> burned either.
>>
>> I am looking at the schematic 4-32 in the Op Manual.
>>
>> Any suggestions as to which device(s) is(are) most
>> likely to have failed, please?
> 
> 
> Check the D2 16V zener diode.
> If its shorted, the relay will never close. D2 and Q2 act as overvoltage 
> protection, a shorted diode will cause a overvoltage protection even 
> when the supply voltage is in range.
> If you are sure providing the right voltage, you may simply cut off the 
> diode. If it was faulty, the TRX will work as usually without the diode, 
> but overvoltage protection is disabled, so be careful with your power 
> supplies!
> 
> 
> 73 de Bert


-- 
Thanks! & 73, doc kd4e
West Central Florida
Drake, Heathkit, Kenwood, TenTec, Yaesu
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