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Groups > sci.electronics.design > #452567
| From | Cursitor Doom <curd@notformail.com> |
|---|---|
| Newsgroups | sci.electronics.design, sci.electronics.repair |
| Subject | Re: Amplifier transistor substitution. |
| Date | 2017-03-19 14:13 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <oam3me$oce$6@dont-email.me> (permalink) |
| References | <ej4csuFe5h4U1@mid.individual.net> <ej6jjmFrr5fU1@mid.individual.net> |
Cross-posted to 2 groups.
On Sun, 19 Mar 2017 16:34:43 +1100, Sylvia Else wrote: > On 18/03/2017 8:27 PM, Sylvia Else wrote: >> The smoke escaped from my old oscilloscope today. I've determined that >> it came out of R740, to the bottom right of the circuit diagram. >> >> https://www.dropbox.com/s/9053dnyr0izv88r/XAMP.PDF?dl=0 >> >> This is because T711 has shorted out. >> >> Not very surprisingly I cannot source a replacement BF472, so I need to >> find a substitute. >> >> This is the final X-axis amplifier, so we're not talking high >> frequencies. Is it likely to be sensitive to the particular transistor >> characteristics? >> >> Sylvia. > > Hmm.... > > They may have supplied a circuit diagram and board layouts in the user > manual, but this thing is clearly not designed to be repaired. There are > multiple wires soldered directly to the boards, including some of those > from the power transformer, and to the side of the board that's not > readily accessible until after they're been desoldered. How did they > assemble this thing? With some kind of right-angled soldering iron? I'm x-posting this to a more appropriate forum, Sylvia, the guys there will be better able to assist you with this...
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Amplifier transistor substitution. Sylvia Else <sylvia@not.at.this.address> - 2017-03-18 20:27 +1100
Re: Amplifier transistor substitution. "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> - 2017-03-18 10:41 +0000
Re: Amplifier transistor substitution. Cursitor Doom <curd@notformail.com> - 2017-03-18 11:13 +0000
Re: Amplifier transistor substitution. bitrex <bitrex@de.lete.earthlink.net> - 2017-03-18 18:15 -0400
Re: Amplifier transistor substitution. Sylvia Else <sylvia@not.at.this.address> - 2017-03-19 12:44 +1100
Re: Amplifier transistor substitution. Winfield Hill <hill@rowland.harvard.edu> - 2017-03-18 19:03 -0700
Re: Amplifier transistor substitution. Sylvia Else <sylvia@not.at.this.address> - 2017-03-19 13:14 +1100
Re: Amplifier transistor substitution. Cursitor Doom <curd@notformail.com> - 2017-03-19 14:11 +0000
Re: Amplifier transistor substitution. Winfield Hill <hill@rowland.harvard.edu> - 2017-03-20 06:20 -0700
Re: Amplifier transistor substitution. Cursitor Doom <curd@notformail.com> - 2017-03-20 23:26 +0000
Re: Amplifier transistor substitution. Phil Allison <pallison49@gmail.com> - 2017-03-18 04:08 -0700
Re: Amplifier transistor substitution. Sylvia Else <sylvia@not.at.this.address> - 2017-03-18 22:42 +1100
Re: Amplifier transistor substitution. "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-03-18 22:01 +0000
Re: Amplifier transistor substitution. Sylvia Else <sylvia@not.at.this.address> - 2017-03-19 16:34 +1100
Re: Amplifier transistor substitution. Cursitor Doom <curd@notformail.com> - 2017-03-19 14:13 +0000
Re: Amplifier transistor substitution. John Robertson <spam@flippers.com> - 2017-03-21 08:34 -0700
Re: Amplifier transistor substitution. Cursitor Doom <curd@notformail.com> - 2017-03-21 18:18 +0000
Re: Amplifier transistor substitution. Sylvia Else <sylvia@not.at.this.address> - 2017-03-20 13:28 +1100
Re: Amplifier transistor substitution. Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-20 10:59 +0200
Re: Amplifier transistor substitution. Sylvia Else <sylvia@not.at.this.address> - 2017-03-21 10:57 +1100
Re: Amplifier transistor substitution - fixed. Sylvia Else <sylvia@not.at.this.address> - 2017-03-22 19:33 +1100
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