Go Back   Home > Forums > >

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

Schottky diode behavior question
Schottky diode behavior question
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools
Old 9th September 2021, 11:31 PM   #1
ranshdow is offline ranshdow  United States
diyAudio Member
Join Date: Jul 2020
Location: SF bay area
Default Schottky diode behavior question

Hi, I'm trying to repair a friend's cheap USB capable turntable. It's powered by a 14V wall wart and has a lot of SMD electronics inside it.

I found an apparent Schottky diode (SMD component with a cathode band marked as SS34, according to Vishay has a 40V max DC blocking voltage) with some odd behavior- I can measure single digit resistance across it in either direction using an ohmmeter. When the unit is receiving power from the wall wart I can't measure a potential difference across the diode, though I can measure about 14V from another, nearby diode. I tried shorting across the suspect diode with a normal 1N4004 diode but that didn't help (not surprising given it's acting like a wire on it's own).

My questions are 1) this is bad behavior for a Schottky diode, right? and 2) is there any reasonable circuit design that would have single-digit resistance in both directions in parallel with a Schottky diode? I have no schematic and wasn't able to find one online.

Trying to decide whether it's worth it to try and replace the Schottky or not. Thanks for reading!
  Reply With Quote
Old 9th September 2021, 11:54 PM   #2
rayma is offline rayma  United States
diyAudio Member
Join Date: Apr 2011
Take it out of circuit for all testing. It will likely behave differently then.
  Reply With Quote
Old 10th September 2021, 04:49 AM   #3
Enzo is offline Enzo  United States
diyAudio Member
Join Date: Sep 2004
Location: Lansing, Michigan
Um... Your diode reads low resistance both ways, and no voltage drops across it? Sure sounds like it is shorted so far.
  Reply With Quote
Old 10th September 2021, 10:42 PM   #4
egellings is offline egellings  United States
diyAudio Member
Join Date: Aug 2010
Location: CA
I get the impression it's shorted.
  Reply With Quote
Old 12th September 2021, 05:56 PM   #5
ranshdow is offline ranshdow  United States
diyAudio Member
Join Date: Jul 2020
Location: SF bay area
Thanks everyone. The turntable’s owner will try and return it so I don’t have permission for surgery.
  Reply to this post


Schottky diode behavior questionHide this!Advertise here!
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
40A 250V Schottky Power Diodes- Has anyone use in Power Amp to replace Diode Bridge? dtm1962 Solid State 10 15th September 2011 08:38 PM
Is SD a Schottky Diode in this schematic? jduffy Tubes / Valves 15 15th March 2007 12:23 PM
Schottky diode as RE? lumanauw Solid State 19 30th March 2005 03:08 AM
HI Voltage & Hi current Schottky diode for sale. ohynot Swap Meet 0 11th June 2004 08:41 PM
Schottky diode bargain dhaen Parts 0 7th November 2003 06:39 PM

New To Site? Need Help?

All times are GMT. The time now is 07:39 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio