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catman

How often does this happen....or am I just cursed?

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G'day all, I think that I must be!  For the last few days I've been trying to build another simple phono stage using two NE5534 op amps.  On power up only channel worked and the other channel was completely dead, and by the way the op amps were brand new and unused straight out of their supplied container. 

 

So I thought well I've made a wiring or soldering error, and I spent the next three days looking for it!  In the end I needn't have bothered as the cause turned out to be one faulty NE5534 op amp.  Simple substitution proved it, and yes by the way I had used high quality 8 pin IC  sockets.  I think that it is time to give up!  Regards, Felix. 

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You didn't give up for three days Felix , why start now ?

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G'day mate, I'm starting to lose faith in certain things!  I have better things to waste time on, to be completely frank!  Regards, Felix. 

 

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20 minutes ago, catman said:

G'day all, I think that I must be!  For the last few days I've been trying to build another simple phono stage using two NE5534 op amps.  On power up only channel worked and the other channel was completely dead, and by the way the op amps were brand new and unused straight out of their supplied container. 

 

So I thought well I've made a wiring or soldering error, and I spent the next three days looking for it!  In the end I needn't have bothered as the cause turned out to be one faulty NE5534 op amp.  Simple substitution proved it, and yes by the way I had used high quality 8 pin IC  sockets.  I think that it is time to give up!  Regards, Felix. 

 

Felix, in terms of diagnosis - given you soldered in the IC sockets, so that opamps could be rolled - I would've thought that trying the 'working' NE5534 in the 'non-working' socket would've been your first step?  If that channel suddenly sprang into life ... then the problem was obviously a dead opamp; if it was still dead then, bcoz it had been working in the other channel ... shirley, you must have a wiring difference in the 'dead' channel?

 

I decided earlier this year I didn't want the problem of soldering in 'dead' semiconductor devices ... so I bought myself a Peak DCA75 that someone mentioned in an SNA thread.  Is there a similar device for opamps?

 

Andy

 

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G'day mate, well you are perfectly right but in my general sense of trustfulness, I honestly didn't think that a brand new op amp would be faulty, but obviously I was wrong!  Regards, Felix.

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Where do you purchase ya' op amps from, Felix?

 

Maybe try a different supplier, maybe RS Components.

 

I either get them from RS here in Aus' or from Partsconnxion in Canada.

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32 minutes ago, elcamry said:

You didn't give up for three days Felix , why start now ?

It’s called fault finding, part of fault finding is process of elimination....this takes time....  especially when everything is solder in.....Good on ya @catman for not giving up.  Never had a op amp to be faulty,   the only faulty opamp are me being over confident and not checking after plug in and stuffing the orientation up!   Only happens once, teaches you a very memorable lesson.....never again!

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32 minutes ago, andyr said:

I decided earlier this year I didn't want the problem of soldering in 'dead' semiconductor devices ... so I bought myself a Peak DCA75 that someone mentioned in an SNA thread.  Is there a similar device for opamps?

 

Andy

 

A Peak DCA75 are only tests for discrete semiconductors, they do not test Opamps.  Opamps are complete amplifier circuits that can have multi discrete devices and are usually 8pin...

http://www.ti.com/lit/ds/symlink/ne5534.pdf

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G'day all, I normally purchase from Element 14, but I have used RS at times.  I am pretty sure that those NE5534's were purchased from Element 14.  Oh well, &%it happens at times!  Regards, Felix. 

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1 minute ago, catman said:

G'day all, I normally purchase from Element 14, but I have used RS at times.  I am pretty sure that those NE5534's were purchased from Element 14.  Oh well, &%it happens at times!  Regards, Felix. 

Sh|t happens,  

 

imaginging powering up a 30A 3 phase device and the power supply goes “bang”.  You’re there for the next for days fault finding to discover you need to replace 2 out of 6 power supply that cost $1000s together to resolve the fault,   And this is stuff that’s made in Japan...... or made in Sweden! 

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Felix,do you use an antistatic wrist strap?

It's easy enough to kill an opamp with the odd stray "zap".

As a Telstra tech we had it drummed into us "use antistatic precautions" especially when handling CMOS boards.

I cringe when I see the local Jaycar staff handling semis without any consideration for antistatic measures.If it doesn't kill the device straight away it may well shorten it's lifespan long term.

Edited by iant

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6 minutes ago, iant said:

Felix,do you use an antistatic wrist strap?

It's easy enough to kill an opamp with the odd stray "zap".

As a Telstra tech we had it drummed into us "use antistatic precautions" especially when handling CMOS boards.

ESD protection is a must with IC's :thumb:

 

ES Damage is cumulative also as we know, and may not kill straight away, but a fault develops down the track instead.

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G'day all, as a former Telstra tech myself I also know the importance of a wrist strap with CMOS stuff but as far as I know the NE5534 is not CMOS, and isn't particularly static sensitive!  Regards, Felix.  

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38 minutes ago, Addicted to music said:

A Peak DCA75 are only tests for discrete semiconductors, they do not test Opamps.  Opamps are complete amplifier circuits that can have multi discrete devices and are usually 8pin...

http://www.ti.com/lit/ds/symlink/ne5534.pdf

 

I'm well aware of all you said, Peter - that's why I asked "is there a similar device for opamps?"  :hmm:

 

Andy

 

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9 minutes ago, catman said:

G'day all, as a former Telstra tech myself I also know the importance of a wrist strap with CMOS stuff but as far as I know the NE5534 is not CMOS, and isn't particularly static sensitive!  Regards, Felix.  

My experience is that it's best to err on the side of caution and regard all semiconductors as ESD sensitive.

 

To stay ESD aware, here’s a quick list of some of the most sensitive electronic devices in use that is susceptible to damage:

  • Microwave devices like Schottky barrier diodes and point contact diodes
  • Discrete MOSFET devices
  • Junction field effect transistors (JFETs)
  • Charged coupled devices (CCDs)
  • Precision voltage regulator diodes
  • Operational amplifiers (Op Amps)
  • Thin film resistors
  • Integrated circuits
  • Very high speed integrated circuits (VHSIC)
  • Laser diodes
  • Silicon controlled rectifiers (SCRs)
Edited by iant

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3 minutes ago, iant said:

My experience is that it's best to err on the side of caution and regard all semiconductors as ESD sensitive.

 

^^^ yes, absolutely!  :thumb:

 

Andy

 

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