Oracle Alexandria Controller Problem solved - diyAudio
Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

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
Reply
 
Thread Tools Search this Thread
Old 31st December 2012, 02:31 AM   #1
diyAudio Member
 
Join Date: Nov 2006
Send a message via MSN to SergeDufour
Default Oracle Alexandria Controller Problem solved

I bought an Oracle Alexandria for parts, as the seller claimed the controller AND the motor was burned. As I know it is nearly impossible to burn a Brushless motor, I was confident to be able to repeat it.

After several tests, it was obvious that some parts were burned. The voltage regulator LM317, the input resistor, and capacitor. But the worst part was the CA 3096, a transistor array that is obsolete. 2 transistors in a package were burn, so I replaced them with discrete resistors. To facilitate the tests, I put very high quality sockets everywhere.

But still nothing... The motor refused to work. I used a led and resistor to check any pulse as I didn't have a scope. Strangely enough, when I touch some pins of the arrays, the motor WOULD start to run with noise. So the motor was definitively ok.

After testing everything several times, nothing seems to be done so it SHOULD work... Then, it hit me. I tried another power supply and magically, it works !

So the voltage I was getting was noisy, and the motor would spin from spurious noise generate across the circuit. I opened the power supply box to find.... a non working 1000 Ufd 35 V cap.
I replaced it with a 50 V 3500 ufd, to be safe.
Now the turntable works like a charm.

Any advice on Oracle ? Ask me !!!!
Attached Images
File Type: jpg image.jpg (711.4 KB, 108 views)
  Reply With Quote
Old 31st December 2012, 08:46 AM   #2
diyAudio Member
 
Join Date: Jun 2004
Location: sheffield
Send a message via MSN to sq225917
Excellent work.
__________________
hoping to pick up some things.
  Reply With Quote
Old 9th January 2013, 03:18 PM   #3
cdebien is offline cdebien  Canada
diyAudio Member
 
Join Date: Apr 2012
Location: Montréal
@ Serge Dufour,

I have the same problem with my TT. On your picture you replace one resistor in your input board but this is not a resistor, this is a pico fuse (1 A, 125 V). I don't know what is the result if you replace a pico fuse by a resistor.

Anyway, I begin to check my board to try to find the problem...
  Reply With Quote
Old 15th February 2013, 08:07 PM   #4
diyAudio Member
 
Join Date: Nov 2006
Send a message via MSN to SergeDufour
I think you are wrong.
Show me on the schematic.
If it's the input resistor, 10 ohm,
I'm still right.
---
I'll check the schematic and be back
  Reply With Quote
Old 15th February 2013, 08:25 PM   #5
diyAudio Member
 
Join Date: Nov 2006
Send a message via MSN to SergeDufour
I checked and you right.
I put a 10 ohm resistor and it works fine.
The problem I had with the board did burn the fuse AND the components AFTER that.
So it was not a reliable protection.
  Reply With Quote
Old 15th February 2013, 08:51 PM   #6
cdebien is offline cdebien  Canada
diyAudio Member
 
Join Date: Apr 2012
Location: Montréal
After few tests, it's appear the problem come from the PSU. I replace it by a printer PSU (30vdc) and everythnig work fine.

Cyr-Marc
  Reply With Quote
Old 15th February 2013, 09:59 PM   #7
diyAudio Member
 
Join Date: Nov 2006
Send a message via MSN to SergeDufour
You're lucky it didn't burn anything else which was my case.
This PSU is often THE problem.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Oracle motor/controller problems - DIY turntable g-horn Analogue Source 26 13th January 2013 12:50 AM
Oracle Alexandria in Detroit Mi-$250 limono Swap Meet 0 26th August 2011 02:21 PM
In need of a subchassis for my Oracle Alexandria Mk II dracoskeeper Analogue Source 10 27th January 2011 04:22 AM
oracle alexandria turntable HELP! fortytwo Analogue Source 6 29th April 2009 09:50 PM
I finally solved my Leach amp problem-too late! Kilowatt Solid State 3 21st June 2002 09:37 AM


New To Site? Need Help?

All times are GMT. The time now is 09:53 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2