jbl gtq 190 - 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 30th December 2009, 06:06 AM   #1
diyAudio Member
 
Join Date: Sep 2006
Default jbl gtq 190

Im wonrking on this amp and it has me puzzled.

For the rectifiers it has a sf163a and a fep16bt in the board looks like the fep16bt is not orignal .

Wondering is the fep16bt = to a u1620?

And second thing is its sending the rail voltage to the speaker outputs

wondering if you can help me on this amp Any help would gretly be appericated
  Reply With Quote
Old 30th December 2009, 06:45 AM   #2
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Those rectifiers should work. An MUR1620 can replace the fep16bt but if it's not defective, there's no point.

Do you have negative rail voltage on the center leg of the sf163a?

Do you have positive rail voltage on the center leg of the fep16bt?
  Reply With Quote
Old 30th December 2009, 06:58 AM   #3
diyAudio Member
 
Join Date: Sep 2006
i have + 31.86 on the u1620 had to replace the fep16 bt it was blown

and i have -26.11 on the other
  Reply With Quote
Old 30th December 2009, 07:03 AM   #4
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
The voltages are not as close (in absolute value) as I'd expect. Place your black meter probe on a non-bridging speaker terminal and measure them again.

With the black probe on the same point, what DC voltage do you have on the power supply pins of the op-amps?
  Reply With Quote
Old 30th December 2009, 07:11 AM   #5
diyAudio Member
 
Join Date: Sep 2006
u1620= 32.34
s= -26.18

i havent measured the op amps yet the power supply fets are getting red hot
  Reply With Quote
Old 30th December 2009, 07:52 AM   #6
diyAudio Member
 
Join Date: Sep 2006
ok here are the readings sf163a= -26.18 mur1620= 32.34

lm318n
Pin1= -4.33
pin2= -6.28
pin3= - 5.03
pin4= -14.49
pin5= -3.62
pin6= -2.34
pin7= -1.61
pin8= -13.63

the other lm318n

pin1= -5.03
pin2= -8.33
pin3= -7.16
pin4= -14.58
pin5= -4.35
pin6= -2.32
pin7= -1.61
pin8= -13.88
  Reply With Quote
Old 30th December 2009, 07:57 AM   #7
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Are these in the audio section? If so, you should have positive voltage on pin 8.
  Reply With Quote
Old 30th December 2009, 08:09 AM   #8
diyAudio Member
 
Join Date: Sep 2006
ok i have negative readings on all of the opamps so i checked the Mur1620 again and the new one i just put in is blown.

Wondering what might be causing theese to blow
  Reply With Quote
Old 30th December 2009, 08:18 AM   #9
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
The rail voltage was OK so the 1620 must be OK. You need to find the regulators. I don't know the amp. Post a photo if you can't locate it.
  Reply With Quote
Old 30th December 2009, 08:53 AM   #10
diyAudio Member
 
Join Date: Sep 2006
i saw some broken solder connections on the driver boards gonna fix them

Also there is a tlo74cn in the amp and that to has no positive voltage on it

The fets were hacked up but they still were good but a hack solder job so im gonna fix thoose nd fix the broken solder connections on the boards then go from there ill try to get my camera to take a decent pic of the amp cause all i see is the drivers for the outputs and on the driver boards just transistors like 2n something
  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
Jbl 2123j spamhead57 Multi-Way 0 27th January 2009 03:37 PM
Jbl Le120h Hyldal Multi-Way 2 26th September 2007 09:25 AM
JBL L56's SuzieQ Multi-Way 0 7th August 2007 06:27 AM
Dayton 295-190 15" DVC RSBosma Subwoofers 4 18th February 2007 01:59 AM
Oscope Dumont 190 infinia Parts 3 9th March 2006 09:45 PM


New To Site? Need Help?

All times are GMT. The time now is 06:12 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