Go Back   Home > Forums > >

Pioneer KEX-M900 troubleshooting
Pioneer KEX-M900 troubleshooting
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
Old 20th November 2020, 09:48 AM   #1
vincegironda is offline vincegironda
diyAudio Member
 
Join Date: Sep 2013
Default Pioneer KEX-M900 troubleshooting

Hi all,

I'm currently restoring a KEX-M900 which came to me as a dead unit.

So far I recapped the DC to DC converter

Recapped the main board, ASL board and DSP board

The unit now powers up, display is good, all menu's working too.

The problem is the unit has 4 pre outs and I have only one channel with good clean audio.

I would like some pointers on tracing the audio path to see if I can find where it's losing audio signal to the dead channels.

What I know so far-

I've tested 2 audio sources

Cassette working fine
Aux input working fine

Both with the same result - audio on one channel only

The dsp board is labelled FR FL RR RL where it outputs to the main board and into the ASL board, I intercepted the signal off all 4 channels and it's only outputting audio on one channel so I think the problem lies within the DSP board or maybe just before it?

I've come this far so would really like to troubleshoot and find the problem, any help or suggestions appreciated

I have a service manual pdf if required

Thanks in advance
  Reply With Quote
Old 20th November 2020, 02:28 PM   #2
Perry Babin is offline Perry Babin  United States
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
I don't have the SM. Have you tried heating/cooling the various components in the circuit to see if it made a difference with any of them?
__________________
Anyone who purchased the repair tutorial, email me (babin_perry@yahoo.com) if you want to download the latest version.
  Reply With Quote
Old 20th November 2020, 11:09 PM   #3
vincegironda is offline vincegironda
diyAudio Member
 
Join Date: Sep 2013
Hi Perry I've emailed you the SM.
  Reply With Quote
Old 21st November 2020, 12:00 AM   #4
Perry Babin is offline Perry Babin  United States
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
On connector CN751, are pins 104 the points where you had only one clean channel?
__________________
Anyone who purchased the repair tutorial, email me (babin_perry@yahoo.com) if you want to download the latest version.
  Reply With Quote
Old 21st November 2020, 05:55 PM   #5
vincegironda is offline vincegironda
diyAudio Member
 
Join Date: Sep 2013
On CN751 there's audio on the FL pin only
  Reply With Quote
Old 21st November 2020, 06:11 PM   #6
vincegironda is offline vincegironda
diyAudio Member
 
Join Date: Sep 2013
I FL is Pin 1 on CN751
  Reply With Quote
Old 21st November 2020, 06:58 PM   #7
Perry Babin is offline Perry Babin  United States
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
That should have been 1-4 not 104.

How do the input and output signals of IC761, 762, 763 and 764 compare?
__________________
Anyone who purchased the repair tutorial, email me (babin_perry@yahoo.com) if you want to download the latest version.
  Reply With Quote
Old 23rd November 2020, 12:57 PM   #8
vincegironda is offline vincegironda
diyAudio Member
 
Join Date: Sep 2013
Hi Perry so before running the tests you suggested I tried tracing the signal further back to IC703 according to the schematic there should be audio on pins 19 and 27

Pin 19 has audio

Pin 27 has no audio

Would it be safe to assume the issue lies with IC703?
  Reply With Quote
Old 23rd November 2020, 01:35 PM   #9
vincegironda is offline vincegironda
diyAudio Member
 
Join Date: Sep 2013
IC 764 has audio on pins 1 and 7 out
and in on pin 5 no signal in on pin 3

IC 761 has no audio in or out
  Reply With Quote
Old 23rd November 2020, 02:43 PM   #10
vincegironda is offline vincegironda
diyAudio Member
 
Join Date: Sep 2013
IC 762 no audio in or out

IC 763 no audio in or out
  Reply With Quote

Reply


Pioneer KEX-M900 troubleshootingHide this!Advertise here!
Thread Tools

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
Pioneer KEX-900 8-pin DIN AUX to 3,5mm audio jack. Mep Car Audio 1 16th September 2020 01:01 PM
Bridging an H&H m900 (400w/ch@4ohm) to run two 16ohm H&H Bass Bins in parallel? Ovation Solid State 8 20th July 2016 09:02 AM
Pioneer KEX-900 blowing fuse dhamia Car Audio 3 14th October 2010 09:25 AM
Pioneer KEX-900 security code dhamia Car Audio 6 22nd September 2010 09:27 AM
Manual and schematic of Pioneer KEX 23 SDK tsteuerwald Car Audio 0 29th March 2007 07:46 AM


New To Site? Need Help?

All times are GMT. The time now is 06:34 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki