Help repairing Pioneer M3 - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 10th April 2013, 08:17 PM   #11
jaycee is offline jaycee  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Norwich, UK
There is no way that amp was repaired by Pioneer, or any reputable service centre - a real repair centre would have used the correct parts, or at least some reasonable substitutes. The original transistors will now be obsolete and unobtainable, so you will have to make substitutes, assuming the amp is not so badly damaged that it is not worth saving.

Transformer - test by putting a 100W incandescent (an old filament type - NOT an "energy saving") bulb in SERIES with the primary winding. This will allow you to test the secondary windings with a multimeter set to AC Volts. You can see the organisation of the windings on top of the transformer, and the voltages you should get.

The next thing I would do, is to take both power amp modules out, reconnect the transformer, and test the power supply part. Leave the bulb in line with the primary winding to protect and indicate a fault. The schematic shows what voltages you should be getting at various terminals. If they don't match up, don't proceed any further. Your bulb should glow brightly at first but dim quickly as the power supply capacitors charge.

On that note, those power supply capacitors are huge. Get yourself a 10W power resistor, say 68-100 ohms. Attach some insulated probes to it. Use it across the capacitors whenever you have had the circuit energised to discharge them. Don't just short them with a screwdriver - it makes a loud bang, a big spark, and will ruin both your screwdriver and the capacitors.

Beware that each capacitor stores nearly 70V - that is 140V total, which can easily kill or seriously injure you.
  Reply With Quote
Old 10th April 2013, 09:22 PM   #12
diyAudio Member
 
Join Date: Mar 2013
Quote:
Originally Posted by jaycee View Post
There is no way that amp was repaired by Pioneer, or any reputable service centre - a real repair centre would have used the correct parts, or at least some reasonable substitutes. The original transistors will now be obsolete and unobtainable, so you will have to make substitutes, assuming the amp is not so badly damaged that it is not worth saving.

Transformer - test by putting a 100W incandescent (an old filament type - NOT an "energy saving") bulb in SERIES with the primary winding. This will allow you to test the secondary windings with a multimeter set to AC Volts. You can see the organisation of the windings on top of the transformer, and the voltages you should get.

The next thing I would do, is to take both power amp modules out, reconnect the transformer, and test the power supply part. Leave the bulb in line with the primary winding to protect and indicate a fault. The schematic shows what voltages you should be getting at various terminals. If they don't match up, don't proceed any further. Your bulb should glow brightly at first but dim quickly as the power supply capacitors charge.

On that note, those power supply capacitors are huge. Get yourself a 10W power resistor, say 68-100 ohms. Attach some insulated probes to it. Use it across the capacitors whenever you have had the circuit energised to discharge them. Don't just short them with a screwdriver - it makes a loud bang, a big spark, and will ruin both your screwdriver and the capacitors.

Beware that each capacitor stores nearly 70V - that is 140V total, which can easily kill or seriously injure you.
I cannot be 100% sure, the amp was repaired before I was even born and all the infos are from my mom memories. She remenber it was sended to pioneer repair centre but when I asked her if someone else also put his hands on it she can't denie or confirm.
The only thing sure is that the job wasn't professionaly done
- There are some miss screws in the case
- The transformer body is damaged as someone tried to pull out the transformer with a flat screw driver. (you can easily see it in the picture)
- The transistors are not original
I excuse myself if it look like I talked badly about pioneer, it wasn't my intention.

Thanks for the infos and for the security tips. I will test the transformer tomorrow and then I will post the results, for now I keep my fingers crossed
  Reply With Quote
Old 11th April 2013, 11:36 AM   #13
kimon is offline kimon  Greece
diyAudio Member
 
Join Date: Aug 2011
Location: Petroupolis,Attica
gde3,if I were you,I would send a PM to the member Sakis.He is an experienced repairer of vintage audio stuff and honest, as far as I can say.He repairs several hundrends of audio devices each year and he can obtain rare parts through his connection in Japan.Maybe he could undertake the repairment of your amplifier.
  Reply With Quote
Old 11th April 2013, 12:13 PM   #14
diyAudio Member
 
Join Date: Jan 2013
This is a very nice amp, probably as good as its big brother the M5 & M7.
Worth every penny and hour you waste on it to repair.
If you want to sell it let me know, I know someone who will pay a fair price for it, these pioneer classics amps are worth quite a lot of money for their age.

If you have the service manual, can I possibly get a copy of it ??

Last edited by manso; 11th April 2013 at 12:16 PM.
  Reply With Quote
Old 11th April 2013, 02:00 PM   #15
rsavas is offline rsavas  Canada
diyAudio Member
 
Join Date: Aug 2012
Location: Ontario
Default Exclusive M3 repair

gde3,
try posting on audiokarma.org, as well. they have an exclusive Pioneer section with lots of experienced people there to help you out.
A service manual is available from
Main scan page
I could not get the SM from this site
Pioneer DV565a Service Manual free download,schematics,datasheets,eeprom bins,pcb,repair info for test equipment and electronics
If some of the O/P TO-3 trany's are gone you probably can get away with MJL21193/MJL21195's as subs. Need to check pinout of the TO-3's, but they are usually all the same.
Transformer secondary windings:
Red-white-red is the o/p trany supply, it is to be +/-66VDC, no load
Green-brown-green is the supply for the front end, +/-83VDC, then these voltages go through a few series pass trany ckts to produce a few secondary supply voltages.
You can send me a PM if you need further detailed help.
Good Luck
Rick
  Reply With Quote
Old 11th April 2013, 02:40 PM   #16
rsavas is offline rsavas  Canada
diyAudio Member
 
Join Date: Aug 2012
Location: Ontario
Correction:
MJL21193/MJL21195's (TO-263) should be MJ21193/MJ21195's(TO-3)
Suggest to test the transformer first using a ohmeter to check for opens, disconnected from the AC line, of course
Then if this is okay, check fuses, best to check DC voltages isolated from the loads & using either a variac or the dim bulb test as was previously suggested. Lets hope that the transformer is okay to start with, the rest can be fixed there after.
If the transformer is smoked, you can probably sub a SX-1050/1250 or similar transformer, if it fits and you can get it for 220/240VAC.

Last edited by rsavas; 11th April 2013 at 02:51 PM.
  Reply With Quote
Old 11th April 2013, 06:56 PM   #17
diyAudio Member
 
Join Date: Mar 2013
Click the image to open in full size.

I tested the transformer, I measured 7.85V for the 7.5V secondary, 68.6V for the 60V and 53.3V for the 47V. So I suppose the transformer is working right
Now the next step will be to remove the amp pcb and test the power supply, but for today I'm finish

By the way I found the original operating instructions and I made a pdf https://hotfile.com/dl/202580470/d65...tions.pdf.html
  Reply With Quote
Old 11th April 2013, 07:28 PM   #18
Mooly is online now Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
That looks promising... all things are now possible

I can outline the next steps for you (if you wish ) which consist of fitting the transformer back and disabling the output stage such that it can not draw excess current. It all has to be done very methodically with a lot of checks along the way to confirm all is well.

Powering of the amp (when that stage is reached) must be done with the bulb tester.
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 11th April 2013, 07:30 PM   #19
diyAudio Member
 
Join Date: Mar 2013
Quote:
Originally Posted by rsavas View Post
gde3,
try posting on audiokarma.org, as well. they have an exclusive Pioneer section with lots of experienced people there to help you out.
A service manual is available from
Main scan page
I could not get the SM from this site
Pioneer DV565a Service Manual free download,schematics,datasheets,eeprom bins,pcb,repair info for test equipment and electronics
If some of the O/P TO-3 trany's are gone you probably can get away with MJL21193/MJL21195's as subs. Need to check pinout of the TO-3's, but they are usually all the same.
Transformer secondary windings:
Red-white-red is the o/p trany supply, it is to be +/-66VDC, no load
Green-brown-green is the supply for the front end, +/-83VDC, then these voltages go through a few series pass trany ckts to produce a few secondary supply voltages.
You can send me a PM if you need further detailed help.
Good Luck
Rick
For the moment the registration to audiokarma is closed. I will check again in the near future. Thanks for the suggestion about the transformer but luckily mine seems to work
  Reply With Quote
Old 11th April 2013, 08:12 PM   #20
diyAudio Member
 
Join Date: Mar 2013
I removed both output stage from the chassis

Click the image to open in full size.


Click the image to open in full size.

Now there's a little problem about connecting the transformer.
Some of the cables are impossible to solder, in order to properly connect the transformer I have to completely disassemble the amp and put some new wires in. This will require some time and patience but at least I will clean all the dust

One more thing about the transformer, since the bottom is quite damaged I need to fix it or it will not fit in the slot. With a bench wise I should be able to realign the borders.
The second problem is the absence of 3 out of 4 nuts who are necessary for attaching the transformer to the case. This nuts were glued with a resin to the transformer, where I can find such resin?
  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
Help! Repairing a Pioneer SA-8100 sonata149 Solid State 15 6th February 2013 08:51 PM
Nad M3 Schematic kimschips Solid State 1 17th July 2012 07:05 PM
audiovector F3 M3 jacack Swap Meet 5 19th February 2010 12:07 AM
2 X PIONEER CDJ-1000 MK3 PLAYER, Korg M3 88-Key Workstation / Sampler,Yamaha Korg holocoast Vendor's Bazaar 0 22nd August 2009 08:03 AM
Meridian M2 or M3 schematics azl Multi-Way 0 22nd February 2009 09:45 PM


New To Site? Need Help?

All times are GMT. The time now is 01:02 PM.


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