Soundstream Reference 405 - diyAudio
Go Back   Home > Forums > General Interest > Car Audio

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 27th December 2011, 10:21 PM   #1
Dr Zeus is offline Dr Zeus  United States
diyAudio Member
 
Dr Zeus's Avatar
 
Join Date: Oct 2010
Default Soundstream Reference 405

Ive got this amp which powers and plays perfectly on the 4x channels. The sub channel has a driver problem, where on the scope only a half waveform is driving my test load.

Seeing this amp has a previously repaired sub channel I started to tinker. The previous repair may have botched up something on the sub's driver board, where the C3789 measures ~-50v DC on all legs. By comparison the other driver on the same board has rail voltage on Legs 1&3, but ~0v on the center leg. The other drivers in the other four channels are measuring the same (Rail / ~0 / Rail) on their legs.

All measurments referencing amp general ground

Is the C3789 in the sub channel defective?
Leg 1: -50v
Leg 2: -50v
Leg 3: -50v

If I lift the center leg of the C3789 I read the following:
Legs 1/2/3: -50v

Pads 1/3: -50v
Pad 2: ~0v

So, when the C3789 is fully inserted, Pad 2 measures -50v.
  Reply With Quote
Old 27th December 2011, 10:50 PM   #2
Dr Zeus is offline Dr Zeus  United States
diyAudio Member
 
Dr Zeus's Avatar
 
Join Date: Oct 2010
Update:

I found the fault withthe driver. Looks like the last time the driver / sub channel blew, it took out a few of the traces on the sub channel's driver board. Im not sure if these driver boards can be replaced, but I was able to complete the former's hard-wire repair. The center leg of the C3789 was supposed to connect leg 1 of the T0-92 transistor under the PCB, yet it wasnt. I simply ran a bridge between the two and the amp is now testing out fine.

My guess is that when the outputs and drivers go, they hurt the driver board. In the previous repair, new drivers were hard-wired in a non-factory arangement to compensate for the damaged board. The former repair must have missed bridging the gap which I found.
  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
Soundstream Reference 405 mike49504 Car Audio 5 28th June 2011 12:09 AM
Soundstream Reference 405 mike49504 Car Audio 43 24th January 2011 05:29 AM
Soundstream Ref.405 railvoltage at sub-ch. gisewhcs Car Audio 4 24th June 2010 07:43 AM
Soundstream 405 sub-channel Problem,plz help! cgpeanut Car Audio 26 7th September 2008 06:40 PM
soundstream reference 405 problem suprmanDL Car Audio 3 21st January 2005 07:46 PM


New To Site? Need Help?

All times are GMT. The time now is 12:16 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