Sony TA-F6B PSU repair - Page 63 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 3rd January 2014, 06:16 PM   #621
Mooly is online now Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
That's great news Jan, well done. I get the feeling that this PSU is extremely fussy on actual devices used.

The bulbs question cropped up earlier although we never found out what they were (from memory).

Sony TA-F6B PSU repair

Might be worth doing a bit of maths (you need the relay resistance and voltage) and drawing it all out putting the voltages in and then work out what "resistance" the bulbs have to be, and what resistance to generate the required relay voltage etc and take it from there.
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 3rd January 2014, 08:43 PM   #622
jan h is offline jan h  Denmark
diyAudio Member
 
Join Date: Feb 2011
I came to the same conclusion, noone really know the specs on those bulbs and Sony keep it a big big secret in the manual.

Google is no friend on this subject, some sites say 250mA others 70mA, most agree on the 6.3V.

The relay is marked 24VDC.

The unoriginal bulbs draws about 200mA@6.3V but as they are unmarked I don't even know if 6.3V is right, but they do light up about the right amount@ 6.3V.

Mounted in the amp they barely glow, and R804 (150Ohm/7W) gets pretty hot.
When I take one bulb out, then the remaning one lights up, R804 still gets warm, but not nearly as much.

Anyway I'll measure the relay resistance and the voltage over the relay and bulb, maybe that will shine some light(!) over the bulbs

Maybe 6.3V/70mA isn't far off.
  Reply With Quote
Old 4th January 2014, 07:37 AM   #623
Mooly is online now Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Lets put some numbers in and say the relay is 600 ohm (wild guess). You have 50 volts across a chain of 150 + 82 + 100 ohm together with the 600 ohm across the 100 + 82. Which all simplifies to 150 ohm in series with 139 ohm. Shove 50 volts across that and you have 0.17 amps available if the bulbs were a short. Lets say each bulb was 6.3 volt at 70ma. That's a hot resistance of 90 ohms per bulb. Two in parallel, 45 ohms.

So if we stick those in the chain we get 150 + 139 + 45. Current available, 0.15 amps. Voltage across relay is 0.15 times 139 which is 21 volts. Sounds reasonable. Voltage across bulbs, 0.15 times 45 ohms which is 6.75 volts. Bit high but in the right ball park and the relay is an unknown. So 6.3 volts 70 ?ma could be about right

Measure the relay. Do you have a Sony part number for the bulbs ?
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 25th February 2014, 08:35 PM   #624
djacco is offline djacco  Netherlands
diyAudio Member
 
Join Date: May 2010
I have a similar problem I get 228V accross C809 is this enough?
  Reply With Quote
Old 26th February 2014, 06:52 AM   #625
Mooly is online now Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Quote:
Originally Posted by djacco View Post
I have a similar problem I get 228V accross C809 is this enough?
The voltage across C809 equals your mains voltage. Netherlands ? 230vac.
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 26th February 2014, 11:30 AM   #626
djacco is offline djacco  Netherlands
diyAudio Member
 
Join Date: May 2010
Quote:
Originally Posted by Mooly View Post
The voltage across C809 equals your mains voltage. Netherlands ? 230vac.
Thanks for the reply, Netherlands has 220V so 228V is a bit high but should be no problem.
My amp worked but I got different en inconsistant volumes on both channels so
I replaced all the caps in the preamp and tone controlls. After that it worked perfectly!
This year I decided to change all caps on the main amp and when I was done and reconnected it to the main the relais would not click and I get a hight pitched beep....
In order to solve the problem I replaced the caps in de PSU but still no successs and I now have to find out what's causing the problem.
I read almost all of this discussion but since I'm not a technician like some guidelines where to start measuring en testing.
  Reply With Quote
Old 26th February 2014, 11:45 AM   #627
Mooly is online now Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
If your not familiar with these type of power supplies then I'm afraid its going to be an uphill struggle. I think we covered most things power supply related in the course of this thread. From what you say, it sounds like you replaced the caps on a working amp and after that the problem appeared... if so then you need to check all your work and the values of parts fitted etc.

Were the caps you fitted in the audio section or the power supply ? The high pitched noise could be the power supply working into a short circuit or trying to supply to much current.
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 26th February 2014, 11:58 AM   #628
djacco is offline djacco  Netherlands
diyAudio Member
 
Join Date: May 2010
Quote:
Originally Posted by Mooly View Post
If your not familiar with these type of power supplies then I'm afraid its going to be an uphill struggle. I think we covered most things power supply related in the course of this thread. From what you say, it sounds like you replaced the caps on a working amp and after that the problem appeared... if so then you need to check all your work and the values of parts fitted etc.

Were the caps you fitted in the audio section or the power supply ? The high pitched noise could be the power supply working into a short circuit or trying to supply to much current.
With time and effort I will succeed in repairing this amp (if nessessary I will put all the old parts back and take it one step at a time :-)

The high pitched sound does not seem to come from the PSU. I disconnected the PSU output and the sound disappeared.
I will check all the replaced parts and read the remaining of this thread.
(I didn't replace the two 0.0015mF 400V caps in the PSU though)
  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
schematics sony Ta- F6B max29 Solid State 5 17th March 2011 07:36 PM
SONY TA 70, repair help needed jojospecial Solid State 2 5th November 2008 08:15 PM
Sony TA-AV670 amp repair calum112 Solid State 2 27th March 2007 08:38 PM
Sony TA-N1 and TA-NR1, how do they sound? lumanauw Solid State 0 28th November 2006 01:51 AM
FS: Sony "Esprit" TA-E901 and TA-N901 pre and power amp MJR Swap Meet 1 6th December 2003 07:55 PM


New To Site? Need Help?

All times are GMT. The time now is 11:14 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