Memphis 16-PR1KD - 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 24th April 2012, 03:42 AM   #1
RiLoWa is offline RiLoWa  United States
diyAudio Member
 
RiLoWa's Avatar
 
Join Date: Aug 2010
Location: Illinois
Default Memphis 16-PR1KD

This amp will briefly cycle audio output and then quit cycling and remain silent. Only the power LED is lit, the other LEDs are off.

Here is what I have on the 494
1: .620V
2: 4.21V
3: .076V
4: .469V
5: 1.531V
6: 3.487V
7: .0157V
8: 13.66V
9: .0156V
10: .0156V
11: 13.66V
12: 13.68V
13: 4.97V
14: 4.97V
15: 4.97V
16: .0156

Q19 and Q33 get hot to the touch.
__________________
Tools - 1. TPI Scope Plus 440 2. B&K 2125 20MHz Dual Trace 3. Sorensen DCR20-50B 4. B&K 4011 5MHz Function Generator 5. Weller WESD51 6. A big hammer

Last edited by RiLoWa; 24th April 2012 at 03:58 AM.
  Reply With Quote
Old 24th April 2012, 11:42 AM   #2
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Do you have rail-rail oscillation on the output transistors when it's producing audio and when it's not producing audio?
  Reply With Quote
Old 24th April 2012, 01:29 PM   #3
RiLoWa is offline RiLoWa  United States
diyAudio Member
 
RiLoWa's Avatar
 
Join Date: Aug 2010
Location: Illinois
When this amp produces audio, it is very brief. It will be difficult to test it while audio is present.

I did see oscillation (very briefly) and then nothing. The scope was set at 50V div. and 10uS and I would be guessing that it was about 1 division peak to peak that I saw.
__________________
Tools - 1. TPI Scope Plus 440 2. B&K 2125 20MHz Dual Trace 3. Sorensen DCR20-50B 4. B&K 4011 5MHz Function Generator 5. Weller WESD51 6. A big hammer
  Reply With Quote
Old 24th April 2012, 03:53 PM   #4
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
These amplifiers (like many of the clones) have problems with transistors overheating. I'd replace any of the transistors that have solder connections that show signs of heat stress. The drivers are also suspect. I'd suggest replacing those as well. They are the 8 transistors closest to the output transistors. If that doesn't solve the problem, you'll need to check voltage across various components.

To make this amp reliable, you'll need to install heatsinks on the driver transistors.
  Reply With Quote
Old 24th April 2012, 11:39 PM   #5
RiLoWa is offline RiLoWa  United States
diyAudio Member
 
RiLoWa's Avatar
 
Join Date: Aug 2010
Location: Illinois
In another thread, it was recommended to replace the MPSA42s with MPSW42s. Would it be the same logic switching the MPSA56s with MPSW56s also?

Are there suitable substitutes for the C3227, C3200, and A1275?
If so, would it make it better to go with a slightly larger package like a TO-126 for the C3227 and A1275?
__________________
Tools - 1. TPI Scope Plus 440 2. B&K 2125 20MHz Dual Trace 3. Sorensen DCR20-50B 4. B&K 4011 5MHz Function Generator 5. Weller WESD51 6. A big hammer
  Reply With Quote
Old 24th April 2012, 11:46 PM   #6
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
The W42s operate at the highest temperatures for the drivers so those should be replaced with the W version. You can replace the A56s with W56s if you have them.

I think the substitution would depend on the application. Transistors used in the switching part of the class D circuit will be more critical than those used in non-switching applications.

Larger packages will be able to dissipate more heat. Install the transistors a bit higher than you normally would to prevent the board from being damaged from the heat.
  Reply With Quote
Old 25th April 2012, 01:34 AM   #7
RiLoWa is offline RiLoWa  United States
diyAudio Member
 
RiLoWa's Avatar
 
Join Date: Aug 2010
Location: Illinois
I come up with KSA1013OTA for the 2SA1275 as a good sub.

It would appear that an MPSW06 might sub for the 2SC3227 if the legs were ECB instead of EBC.

I do not find a suitable sub for the 2SC3200.

The two harder to find parts are the two that heat up the most as the amp sits right now.
__________________
Tools - 1. TPI Scope Plus 440 2. B&K 2125 20MHz Dual Trace 3. Sorensen DCR20-50B 4. B&K 4011 5MHz Function Generator 5. Weller WESD51 6. A big hammer
  Reply With Quote
Old 25th April 2012, 01:38 AM   #8
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
In some of these amps, I used a KSA1220A in place of the a1275.

What's the circuit board designation for the c3200?
  Reply With Quote
Old 25th April 2012, 02:13 AM   #9
RiLoWa is offline RiLoWa  United States
diyAudio Member
 
RiLoWa's Avatar
 
Join Date: Aug 2010
Location: Illinois
There are two C3200s, Q19 and Q18. It is Q19 that gets hot.

Q33 is the C3227 that gets hot.

The data sheets look almost identical on the 1013 to replace 1275 (Q21) unless I am not looking far enough into the specification. I will note the A1220 as a possible.

All of these are in the transistor array behind the eight driver A56s & A42s.

I found a place that claims to have the correct part numbers on hand (C3200 & C3227), but I have never done business with them.
__________________
Tools - 1. TPI Scope Plus 440 2. B&K 2125 20MHz Dual Trace 3. Sorensen DCR20-50B 4. B&K 4011 5MHz Function Generator 5. Weller WESD51 6. A big hammer
  Reply With Quote
Old 25th April 2012, 02:24 AM   #10
RiLoWa is offline RiLoWa  United States
diyAudio Member
 
RiLoWa's Avatar
 
Join Date: Aug 2010
Location: Illinois
Maybe a BD139 in place of the C3227 at Q33?
__________________
Tools - 1. TPI Scope Plus 440 2. B&K 2125 20MHz Dual Trace 3. Sorensen DCR20-50B 4. B&K 4011 5MHz Function Generator 5. Weller WESD51 6. A big hammer
  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
Memphis 16-PR1KD amp repair help (pix) raverx3m Car Audio 15 24th April 2012 09:07 AM
Memphis 16-MCA3004 Dr Zeus Car Audio 19 24th February 2012 10:54 PM
Memphis 16-PR1KD timwebb Car Audio 13 6th July 2010 11:13 PM
problem with my amp memphis 16-pr1kd pollo1008 Class D 0 29th December 2009 11:20 PM
memphis 16-pr1kd chev55_steve Car Audio 0 2nd January 2009 11:46 AM


New To Site? Need Help?

All times are GMT. The time now is 09:53 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