Search found 7 matches

by bambadoo
Wed Jan 03, 2018 4:53 am
Forum: Amplifiers
Topic: MF2500 throwing 68 DCvolt out on right channel
Replies: 6
Views: 113

Re: MF2500 throwing 68 DCvolt out on right channel

Have one that did excactly the same. Many parts are fried including one pair of output transistors.
Look here
viewtopic.php?f=17&t=1118

and here

http://www.diyaudio.com/forums/solid-st ... f2500.html

CJ was kind enough providing schematics.
by bambadoo
Mon May 01, 2017 3:08 am
Forum: Troubleshooting/problems/manuals/schematics
Topic: CJ MF2500 fault - smoke
Replies: 3
Views: 195

Re: CJ MF2500 fault - smoke

Q13 (small signal) mje340 on the left channel was also gone. CJ has stopped responding. Anyone know where to get a service manual? After it is finished I will chech bias dc offset and so on. Also did a recap of the psu and changed one fuseholder there. http://www.hifisentralen.no/forumet/attachments...
by bambadoo
Sat Apr 22, 2017 7:55 am
Forum: Troubleshooting/problems/manuals/schematics
Topic: CJ MF2500 fault - smoke
Replies: 3
Views: 195

Re: CJ MF2500 fault - smoke

Only one pair of output transistors were gone.
1 2sc3282 and 1 2sa1302..

Anyone know where to get a couple of genuine Toshibas?
by bambadoo
Fri Apr 21, 2017 6:25 am
Forum: Troubleshooting/problems/manuals/schematics
Topic: CJ MF2500 fault - smoke
Replies: 3
Views: 195

Re: CJ MF2500 fault - smoke

A loose fuse holder (only soldered at one end to pcb) Q12 (mpsu60l), Q23(nsdu57) and R12 (100r) minimun are broken on left channel. Waiting for some equipment so I can du some more digging..
Probably more that is broken.
by bambadoo
Wed Apr 19, 2017 5:26 pm
Forum: Troubleshooting/problems/manuals/schematics
Topic: CJ MF2500 fault - smoke
Replies: 3
Views: 195

CJ MF2500 fault - smoke

Hi, have had this for a while but have never tried it Anyway - replaced all fuses (3 were blown) just to test. On fuse on the back and 2 on the pcb. Connected a DMM on each loudspeaker terminal and fired up. Left channel showd 72Vdc - Right channel ~100mV. After some seconds a bit of smoke appeared ...
by bambadoo
Tue Apr 18, 2017 5:08 pm
Forum: Member Presentation Thread
Topic: New member from Norway
Replies: 1
Views: 140

New member from Norway

Hi there. Have alot of equipment including a MF2500.
It has some issues which I hope can be fixed.