Micromega Solo CD Player - help!! - Page 3 - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, 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 6th July 2011, 06:29 PM   #21
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Thanks for the pic. I don't think for a moment the transformer is suspect.

Now I don't know how easy this thing is for you to work on and take measurements but, in the absence of any circuit diagrams it makes sense not to overlook anything. Remember though that these are basic tests only so don't get your hopes up too much.

OK we have to start somewhere. Please be careful measuring voltages... no danger, but a slip with the meter probes could cause damage. All the readings are taken with the black lead of the meter on chassis ground or "zero" volts point which can be the outer ground part of the RCA audio sockets. Some of these measurements may seem a bit random and even non related parts of the circuit but I'm working off the pics which is easier to describe from and trying to cover all supply possibilities.

Pin markings on "normal" IC's begin with pin 1 at the spot or mark in the corner and work round the IC. So in the first one here pin 1 and 14 are opposite each other.

Looking at your picture in post #10 measure the voltage on pin 14 of the IC marked MC74HCD04N. It should be 5 volts.

To the left of that IC is a smaller one marked LF356N. Measure the voltages on pins 4 and 7. They should be equal and opposite. For example +9 volts on pin 7 and -9 volts on pin 4. The actual voltage could be anywhere from 5 to 18 volts depending on the design.

Thats a first step...

I'll post a bit more in a minute.
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 6th July 2011, 06:34 PM   #22
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
And these 6 measurements here A to F
Attached Images
File Type: jpg Solo.jpg (629.6 KB, 106 views)
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 6th July 2011, 06:41 PM   #23
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
And on the TDA5709 (on the other board) the voltage on pins 6, 11 and 17.

What is on each ?

Also pins 4 and 8 of that little 8 legged IC the 4560. What is on those too.

It will probably be Friday before I can look in again in detail...
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 6th July 2011, 07:04 PM   #24
diyAudio Member
 
Join Date: Jan 2010
Thanks very much - when I can get some good daylight I will record the voltages!

Regards

David
  Reply With Quote
Old 6th July 2011, 07:08 PM   #25
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
OK... take it slow and write everything down. What we are looking for is any obvious error, missing supply or a very low supply etc.

Checking supplies is the first rule of faultfinding really... but as I say don't get your hopes up too much.
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 6th July 2011, 08:52 PM   #26
guido is offline guido  Netherlands
diyAudio Member
 
guido's Avatar
 
Join Date: Mar 2002
Location: diepe zuiden
Try to find somebody in your neighbourhood (on this forum or similar) who is familiar with philips/marantz players. Would be easy for such a person to find the problem.

Checking the supplies is a good start and do-able, but after that you will soon need a scope to poke around.

I'm too far away myself
__________________
GuidoB
  Reply With Quote
Old 6th July 2011, 09:43 PM   #27
diyAudio Member
 
Join Date: Jan 2010
Quote:
Originally Posted by Mooly View Post
And on the TDA5709 (on the other board) the voltage on pins 6, 11 and 17.

What is on each ?

Also pins 4 and 8 of that little 8 legged IC the 4560. What is on those too.

It will probably be Friday before I can look in again in detail...
Measured the following:

MC7HCD04N Pin 14 4.69V

L356N Pin 4 15.09V
Pin 7 -14.93V

On Main Board

A -4.75V

B 0.00V

C -4.98V

D -4.97V

E -4.79V

F 0.00V

Also

TDA 5709

Pin 6 -4.58V

Pin 11 4.84V

Pin 12 -0.08V

4560

Pin 4 -13.87V

Pin 8 -9.7V

Some were a little tricky to measure but I would think are pretty accurate

David
  Reply With Quote
Old 7th July 2011, 06:26 AM   #28
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
They all sound good although the last one is a little unexpected and worth investigating... but again, don't get your hopes up, it may be normal.

The 4560 is a dual opamp and I suspect used for motor control. I would have expected pin 8 to be a positive reading. That said -9 on pin 8 and -15 on pin 4 is still a "valid" supply depending on the exact circuit application but it stands out a mile as not "normal".

I would recheck that reading and try and trace back pin 8 and see where it goes...

If anyone else is reading this do they know what other Philips models that "front end" board is used in ? It looks a standard Philips creation.

Those solid core wires used by Philips (they look like those anyway) can be fragile and fracture if they are bent around a lot so beware.

It will tomorrow before I can look again
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 7th July 2011, 09:51 AM   #29
diyAudio Member
 
Join Date: Jan 2010
My apologies but pin 4 on the 4560 measured at +13.87V and not -13.67V - I transcribed it to my pc incorrectly

I re-checked pin 8 and it is reading -9.7V

I have also attached a close up pic of the rear of the board - with the 8 pins of the 4560 top left on the rear view of the board - pin 8 is nearest the edge fourth from the right!

I attach also a pic of components in close proximity to the 4560

Once again thanks for your help

David
Attached Images
File Type: jpg P1030566a.jpg (330.1 KB, 91 views)
File Type: jpg P1030567a.jpg (325.4 KB, 86 views)
  Reply With Quote
Old 8th July 2011, 11:13 AM   #30
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Hi David...
It seems the supplies as far as we can tell are OK. Without seeing a circuit diagram now I think realistically that's about as far as you can take it with only a multimeter for testing.

The CD spinning backwards could be a motor/drive/amplifier problem but without at least the correct circuit to give you very specific tests to perform, I fear it's beyond the scope of a thread such as this.
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  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
Schematic for this beautiful Micromega Solo, Trio and CD f1 (first edition) wanted tiefbassuebertr Digital Source 17 30th October 2013 02:56 AM
Micromega (LEEDH) CDF-2 CD player Sleurp Digital Source 2 21st January 2008 12:51 PM
CD Player Micromega CDF1 PRO hawktoc Digital Source 9 8th November 2005 08:35 PM
Micromega Stage 3 CD Player SPWONG Digital Source 2 7th December 2004 07:40 PM
Micromega Stage 3 CD Player SPWONG Parts 0 19th November 2003 06:37 AM


New To Site? Need Help?

All times are GMT. The time now is 07:51 AM.


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