• Please note that there are a few updates and clarifications made in the Audiokarma Rules, mostly relating to advertising and the addition of the new "Paying it Forward" & "Giving back" forums in the AudioKarma Audio Marketplace section.

PIONEER SX-3900 - Cracked Output transistor sockets

Fonzombie

Fonzombie

New Member
I have a pioneer sx-3900 and it seems to be working great - i opened it up to give it a look through and found on the bottom side connected to the heat sink most, if not all, of the white silicon output transistor heads were cracking. Is there a way to fix this??? The rest of the unit is in primo condition but I'm frightened to run it after noticing this defect. I saw mention of a link to this exact question stated in a post by "solution room" but i cant find the link for the life of me- can anyone help?
 
Register to hide this ad
there are a few types of sockets available . easiest would be the screw terminal ones . or perhaps cpu fan cable sockets with wires already attached
 
Several members of the board have recommended these sockets. I believe the original member who proposed them was either Markthefixer or Solutionroom. I have now used them on 3 different SX-3800/3900 amps and they work great:

d7000_transistor_phoenix_socket_zpsutk1bd7t.jpg


I believe they are Mouser part 651-1757022.
 
princever said:
Several members of the board have recommended these sockets. I believe the original member who proposed them was either Markthefixer or Solutionroom. I have now used them on 3 different SX-3800/3900 amps and they work great:

d7000_transistor_phoenix_socket_zpsutk1bd7t.jpg


I believe they are Mouser part 651-1757022.
Click to expand...
INCREDIBLY HELPFUL- is this something a novice can do? And are there any videos? Or links?
 
princever said:
Several members of the board have recommended these sockets. I believe the original member who proposed them was either Markthefixer or Solutionroom. I have now used them on 3 different SX-3800/3900 amps and they work great:

d7000_transistor_phoenix_socket_zpsutk1bd7t.jpg


I believe they are Mouser part 651-1757022.
Click to expand...
so i found these but they dont seem to look like the bit that gets plugged into that brass looking sockets with tue screws?
 

Attachments

  • image.png
    image.png
    124 KB · Views: 30
They (651-1757022.) are. The mouser pictures are generic, due to the modular nature of that series of parts. They are intended to be half of a 15 amp rated connector pair, but we just use half and plug the transistor leads into where the brass pin from the other half goes in.
 
markthefixer said:
They (651-1757022.) are. The mouser pictures are generic, due to the modular nature of that series of parts. They are intended to be half of a 15 amp rated connector pair, but we just use half and plug the transistor leads into where the brass pin from the other half goes in.
Click to expand...
Ok, many thanks - I'm gonna order these now and I will post some pics. This procedure seems pretty easy (plug and play?)- am I clear in thinking that - is there a link or a walkthrough somewhere?
 
They are pretty much plug and play. Just be careful when unwrapping the wires off the existing sockets. They get nicked where they go across the corners of the posts and break easily. If you have enough slack its easier to cut that part off and strip some insulation for a fresh surface.
 
princever said:
They are pretty much plug and play. Just be careful when unwrapping the wires off the existing sockets. They get nicked where they go across the corners of the posts and break easily. If you have enough slack its easier to cut that part off and strip some insulation for a fresh surface.
Click to expand...
Thanks so much for the help - they should be arriving today!!! I will reach out when they get here
 
princever said:
Several members of the board have recommended these sockets. I believe the original member who proposed them was either Markthefixer or Solutionroom. I have now used them on 3 different SX-3800/3900 amps and they work great:

d7000_transistor_phoenix_socket_zpsutk1bd7t.jpg


I believe they are Mouser part 651-1757022.
Click to expand...
Ok so I got the sockets from mouser i got the right part for the "contact terminal block" but what I need is circled in the picture... I don't know what its called, not the piece with the screws but the silicon bit thats plugged... any idea what thats called - is that the out put transistor? thats what i needMOUSER.jpg
 
Yes those are the output transistors, but based on this...

Fonzombie said:
I have a pioneer sx-3900 and it seems to be working great
Click to expand...

Why do you believe that they need to be replaced?

Those devices will have numbers and letters on them that will help you identify the device types.
 
THOSE devices (output transistors) are cracked??

You had better post some pictures of the "cracks" in-situ... This is important.

If so, it isn't just a simple "replacement"....

Yet you report : "seems to be working great"
 
princever said:
Several members of the board have recommended these sockets. I believe the original member who proposed them was either Markthefixer or Solutionroom. I have now used them on 3 different SX-3800/3900 amps and they work great:

d7000_transistor_phoenix_socket_zpsutk1bd7t.jpg


I believe they are Mouser part 651-1757022.
Click to expand...
Is the soldier at the bottom where the plug meets the transistor?
 
No solder. The are dual wiping spring contacts with 0.20" center spacing, and simply plug onto the device. The screw terminals are for the wires only.
 
Fonzombie said:
Ok so I got the sockets from mouser i got the right part for the "contact terminal block" but what I need is circled in the picture... I don't know what its called, not the piece with the screws but the silicon bit thats plugged... any idea what thats called - is that the out put transistor? thats what i needView attachment 750681
Click to expand...

Which output transistor do you need? 2sc2526 or 2sa1076? both are available on ebay.
https://www.ebay.com/itm/2SA1076-16...498349&hash=item1a41637d40:g:EgkAAOSw9p9aY0YC
I bought 6 pcs of 2sa1076 from above seller last year and believe these trs are genuine(I live in Taiwan).
 
ivandezande said:
He was last online a year and a half ago and this thread is three years old....he's not going to see your reply or care anymore I would guess.
Also I would bet money those are fakes.
Click to expand...

According to my limited experience the fake MT-200 Trs I have ever seen are remarked,
I bought 10 pcs of 2sa1076 from a China Taobao seller few years ago,the trs I received are different from the trs on the pic posted by seller.
they are remarked.later I returned those trs and got my money back.
2sa1076 a001.jpg 2sa1076 a002.jpg

You may compare them with the 2sa1076 I purchased from the Taiwanese seller.
Sa9800 Output Trs 2sa1076G a001.jpg
 
Last edited:
FYI, it is a Fujitsu RM-60 package,shown in the data sheet, the MT-200 is a Sanken package, now going obsolete. The only viable/trusted packages are TO-3P and TO-264 from OnSemi and a few Sankens. Even Toshiba's power transistors are getting hard to find.
 
You must log in or register to reply here.
Back
Top Bottom