Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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

TV PSU giving me nightmares
TV PSU giving me nightmares
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 Search this Thread
Old 26th August 2009, 05:26 PM   #11
Archimedes is offline Archimedes  South Africa
diyAudio Member
Archimedes's Avatar
Join Date: May 2005
Location: Johannesburg
Hi All

After replacing most of the electrolytics I still had not managed to sort out the problem. I actually went to the point of removing the opto isolator and then noticed that the voltage immediately on switch on went up to 250V on the 142V output connected to a 656ohm/80W load (not connected to the Main board) This cleared up the possibility of a faulty transformer. You will never believe what the actual culprit was. R810 is a 0.27ohm resistor and showed no signs of being burnt or cracked and I removed it completely from the board and measured it. It turned out to be 5.1ohms Go figure!

In any event I replaced this resistor and voila everything came back to normal. The TV is now sorted out and has been running well for the last 5 days.

The lesson I learnt from this experience is that even though something looks to be in perfect condition it might not be.
  Reply With Quote
Old 26th August 2009, 10:59 PM   #12
star882 is offline star882  United States
diyAudio Member
star882's Avatar
Join Date: Mar 2007
If a resistor is repeatedly cycled to or near its ratings, internal cracks may form that result in intermittent faults and increased resistance. The fix is to replace it with one a size larger.
"Fully on MOSFET = closed switch, Fully off MOSFET = open switch, Half on MOSFET = poor imitation of Tiffany Yep." - also applies to IGBTs!
  Reply With Quote


TV PSU giving me nightmaresHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Turntable giving out too much treble. thelostpatrol Analogue Source 2 5th April 2007 01:49 AM
my SY CCS is only giving me 15mA Shoog Tubes / Valves 17 6th March 2006 07:43 PM
Giving them the horn? JRKO Multi-Way 7 3rd July 2004 05:49 PM
not giving up on the SOZ MEGA_amp Pass Labs 3 19th May 2004 08:33 PM

New To Site? Need Help?

All times are GMT. The time now is 05:27 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio