Very dim digital readout - 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 17th August 2010, 03:04 AM   #1
srinath is offline srinath  United States
diyAudio Member
 
Join Date: Feb 2010
Default Very dim digital readout

In this str-d865 sony amp I just got, the digital readout on the front is very very dim. Anyone know what controls it and how to test and fix it ?
Thanks.
Srinath.

Last edited by srinath; 17th August 2010 at 03:05 AM. Reason: typo
  Reply With Quote
Old 18th August 2010, 10:03 AM   #2
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
They are generally backlighted with an ordinary incandescent lightbulb, change it.
__________________
Candidates for the Darwin Award should not read this author.
  Reply With Quote
Old 18th August 2010, 12:13 PM   #3
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
If it's vacuum flourescent type then caps on or for generating the -30 or so rail are suspect. Would have to see circuit, but caps are favourite as they are often used in a voltage doubler arrangement.

Similar thread on CD display here... the principle is the same and the voltages used will be similar.
Marantz CD5000 - display very dull - help?
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 18th August 2010, 01:07 PM   #4
srinath is offline srinath  United States
diyAudio Member
 
Join Date: Feb 2010
Default Bulb ? cap ?

Djk: Bulb would be so easy, but schematic doesn't say bulb and I dont believe its thick enough to house even a tiny bulb.
Mooly: That story didn't end too well on the marantz display BTW.

I have found that the face plate is tinted a very deep red, making it 2 X hard to get it to be bright. Maybe they put in clear in the middle after finding out its dim on later models. No idea.
Thanks.
Cool.
Srinath.
  Reply With Quote
Old 18th August 2010, 04:46 PM   #5
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Lol, in post 22 he said it fixed it... if the original cap was OK the display wouldn't have altered.

Anyway caps are a big problem... but you really need to see the circuit. For example some Aiwa music centres (Aiwa, part of Sony at the time... hmmm) used two unequal value electroylitics of 33 and 22uf from memory and they failed like they were going out of fashion. These were used to derive the display volts.

The problem is knowing how bright they are when new. Signs of a duff display can be unequal rightness of segments, them looking brighter directly where the heaters pass over them.
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 18th August 2010, 06:52 PM   #6
srinath is offline srinath  United States
diyAudio Member
 
Join Date: Feb 2010
Oh this thing is dimmest in the center, where it matters most.
Let me read that thread.
Thanks.
Cool.
Srinath.
  Reply With Quote
Old 18th August 2010, 06:55 PM   #7
srinath is offline srinath  United States
diyAudio Member
 
Join Date: Feb 2010
Post 29 he says it only made it just slightly better.
Thanks.
Srinath.
  Reply With Quote
Old 19th August 2010, 05:59 AM   #8
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
If the illumination is uneven it sounds like the display itself.
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 19th August 2010, 11:28 AM   #9
diyAudio Member
 
Join Date: Jul 2003
Location: Dona paula, Goa
If u bought it old, then there may be dust settled behind the front panel.

Gajanan Phadte
  Reply With Quote
Old 19th August 2010, 12:15 PM   #10
srinath is offline srinath  United States
diyAudio Member
 
Join Date: Feb 2010
It is used, and quite old but there is no dust. The whole thing is very clean.
Thanks.
Srinath.
  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
Digital potentiometer with readout Peter Roodzant Solid State 8 23rd November 2008 02:45 PM
LCD readout - broken ? or bad joints 3Dgeek Digital Line Level 16 31st October 2008 10:56 AM
Pioneer 563a Display Readout problems LuckyLyndy Digital Source 0 22nd October 2005 02:51 AM
DMM ac readout with signal Ralph Everything Else 1 18th August 2005 07:42 AM


New To Site? Need Help?

All times are GMT. The time now is 03:39 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