Alpine MRP-M350 - 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 29th October 2010, 03:29 AM   #1
RiLoWa is offline RiLoWa  United States
diyAudio Member
 
RiLoWa's Avatar
 
Join Date: Aug 2010
Location: Illinois
Default Alpine MRP-M350

This amp has two IRF5305 and two IRFZ44N on the outputs. I found that one of the IRF5305's is shorted. I then removed all of the outputs to confirm they are ok, which they seem to be. When powering this amp with out any outputs installed, the power LED pulses and it makes a "squeaking" sound.

This is the first Class D amp I have attempted to work on. Does this amp require good outputs to be installed in order to power up correctly OR is there some other problem upstream from the outputs?

The attached picture was taken just after I removed the one bad output.
Attached Images
File Type: jpg MRP-M350 Board 2.jpg (663.0 KB, 79 views)
  Reply With Quote
Old 29th October 2010, 03:51 AM   #2
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
If the half with the missing output is causing DC to appear on the speaker terminals, it could be going into protect.
  Reply With Quote
Old 29th October 2010, 03:59 AM   #3
RiLoWa is offline RiLoWa  United States
diyAudio Member
 
RiLoWa's Avatar
 
Join Date: Aug 2010
Location: Illinois
With all of the outputs removed, I am not measuring any DC on the output terminal. Should I re-install the three good components and re-check for this?
  Reply With Quote
Old 29th October 2010, 04:04 AM   #4
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Is the DC voltage on pin 3 of the upc494 remaining near 0v DC? Or is pulsing towards 5v?
  Reply With Quote
Old 29th October 2010, 04:32 AM   #5
RiLoWa is offline RiLoWa  United States
diyAudio Member
 
RiLoWa's Avatar
 
Join Date: Aug 2010
Location: Illinois
I measure it to pulse between ~81.0mV and ~87.5mV.
  Reply With Quote
Old 29th October 2010, 04:46 AM   #6
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Do have a scope?
  Reply With Quote
Old 29th October 2010, 12:48 PM   #7
RiLoWa is offline RiLoWa  United States
diyAudio Member
 
RiLoWa's Avatar
 
Join Date: Aug 2010
Location: Illinois
Yes
  Reply With Quote
Old 30th October 2010, 12:36 AM   #8
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Is the upc494 intermittently producing square wave pulses on pins 9 and 10?
  Reply With Quote
Old 30th October 2010, 12:56 AM   #9
RiLoWa is offline RiLoWa  United States
diyAudio Member
 
RiLoWa's Avatar
 
Join Date: Aug 2010
Location: Illinois
Both pins 9 & 10 look identical on the scope, but I wouldn't call it a square wave. It looks more like a dirty sine wave that apears in rhythm with the audible pulsing of the LED.
  Reply With Quote
Old 30th October 2010, 02:19 AM   #10
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Set the scope to 5v/div and 2ms/div. Do you see groups of pulses that deflect the trace to about 2 vertical divisions?
  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
Alpine MRP-F200 mike49504 Car Audio 3 27th May 2010 08:29 AM
Service maanual for MRP-M350 DigiSoft Car Audio 0 17th March 2010 09:26 PM
alpine mrp m650 repair candyman122 Car Audio 6 21st November 2009 10:18 AM
Alpine MRP-M1000 argonrepublic Car Audio 2 11th August 2009 03:28 PM
ALPINE 4 Channel Amp MRP-F240 Livin Swap Meet 0 5th April 2008 07:57 PM


New To Site? Need Help?

All times are GMT. The time now is 01:09 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