• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

2230 recap

runningdog said:
Yes and yes. Black to chassis, red to J404, 27.2V.
Click to expand...
Thanks! Hopefully this will help GT, and I have a 2230 open on my workbench right now, so I'm going to do the same test just to get my feet wet and begin to put what I see on the board in context with what I see on the schematic. :beerchug:
 
Dearslayer said:
Also when and if I do get this up and running I'd like to replace those Greenies for the 400 board and Parts Connexion suggest the below. Would this be a good equivalent?

ODROP-76311
0.47uF / 400V, Orange Drop Series 715P, Polypropylene Film & Foil Capacitor, 20.8mmD x 22.4mmH x 41.9mmL, Each
$2.95 pcX USD Price
Click to expand...

The Orange Drops are very large compared to the Panasonic ECW-F2 (8.4mm x 17mm x 13mm) and would have to be mounted away from the board ground plane which would make it susceptible to picking up noise (see here for more details, http://sound.whsites.net/articles/capacitors.htm#s60).
 
Steven... Trying very hard to understand so can't thank you enough for trying to figure this out on my behalf. Looking at the 400 board I see the three pins next to the large cap. They are noted on the silk screen from left to right as J402/403/401 and that's where the two large Red/White wires ( I presume power ). That's the only 3 pins on that side. J404 is on the other side of the board between J406/405.
 

Attachments

  • image.jpeg
    image.jpeg
    139.7 KB · Views: 31
  • image.jpeg
    image.jpeg
    160 KB · Views: 30
Dearslayer said:
...Looking at the 400 board I see the three pins next to the large cap. They are noted on the silk screen from left to right as J402/403/401 and that's where the two large Red/White wires ( I presume power ). That's the only 3 pins on that side. J404 is on the other side of the board between J406/405.
Click to expand...

J401 and J402 are the signal inputs for the left and right channel, J403 is the common ground. J404 is the DC voltage input. You can test with the DBT in place (this will avoid any catastrophic mishap).
 
Ok so DBT in place,and black lead to chassis and because there is no pin at J404 to connect to,I just try to clip the Red lead to the little bit of exposed red wire where it enters the hole in the board? Sorry for being a PITA ,I just want to be sure. I know I have to get my feet wet but I just want to follow the instructions carefully and not mess up on my part.
 
If it is easier, you can also read the voltage by clipping onto the jumper R417 (on your board). Look at Fig. 15 (on pg. 15) of the service manual to see what is connected to the local decoupling capacitor C409.
 
This is how I hooked the DVM.... Red to the R417 jumper on the board and Black to Chassis. Receiver hooked to DBT so reading taken with it on. Hope this is the correct way to do it. The reading isn't 27.2 as the Picts will indicate.
 

Attachments

  • image.jpeg
    image.jpeg
    151.6 KB · Views: 30
  • image.jpeg
    image.jpeg
    111 KB · Views: 26
Was the DBT dim when the V measurement was taken? The 27.2V derived from the P800 board: 35.6V regulated output passes through R006 and then onto the P400 board. Check the voltage at J808 on the P800 board.
 
The J808 reading is fine. There is likely a partial short on the P400 board that is resulting in the expected 27.2V being ~17V. It may be one the replacement transistors; try doing the diode test on the transistors in situ and the power off.
 
Will try that tomorrow and report back. It's been a frustrating day but it's been made easier with all the help here. Thanks so much.
 
For what it's worth, I tested the voltage at J404 on the open 2230 on my bench and it measured 29.2. That seems OK, but when I went to check power out with scope, had a problem and started another thread to address that.
 
Leestereo said:
The J808 reading is fine. There is likely a partial short on the P400 board that is resulting in the expected 27.2V being ~17V. It may be one the replacement transistors; try doing the diode test on the transistors in situ and the power off.
Click to expand...



Trying to understand how to measure the two different transistors and just realized that 4 are NPN and 4 are PNP so afer reading the link by EchoWars I guess I have to measure them differently correct?
 
To check NPN, set meter to diode test. Put positive lead on base. Touch negative lead to emitter. You should get a reading of .45 to .6. Touch negative to collector and look for same result. If you put negative on base and touch E and C you should get no conduction. For PNP reverse it. Negative to base should get .45 to .6 when positive touched to E and C. With pisitive on base you should get no conduction when touching negative to E and C.
Just try it on a couple of loose transistors till you see how its supposed to work.
 
Well it’s been a couple days since I had the time to go back at trying to find out the issue I’m having with no sound. Been working long hours. Anyway I decided to replace some or all of the new transistors last night, with the old ones that I had removed. I tried testing the 992’s with the DVM while on the board, and got a proper reading however when trying the 1815’s I couldn’t get a proper reading so I started by removing the new 992’s and putting the old ones back in….still no sound. I then removed the 4 “ 1815’s” and put the old ones back in and ……. I have sound. I could be wrong here but I believe I may have the wrong transistors for the 1815’s. The package has Part # 512-KSC1815YTA but the marking on the transistors themselves don’t match with the Datasheet on the Mouser site for the 1815’s. The actual marking on the Transistor is as follows…….BC547 B-F38 . From what I see it doesn’t match with the data sheet for the actual 1815 shown below and the top mark should be YC&3. Not sure if I’m interpreting this whole mess correctly or just confusing it more. Hopefully someone with a better understanding could confirm. If this is the case then I guess I should have not assumed that the correct part was in the package. I usually check all the Caps before installing so I don’t know why I didn’t check these. At any rate I guess if they are the wrong ones then I will have to order the correct ones. Bottom line is that I have sound now after all the stressing and confusion, but I’d still like to replace those 8 transistors. Lesson leaned perhaps? Or could have been a fluke, and the transistors are the correct ones, and there was a different issue that corrected itself?????


Mouser Part #:

512-BC547

Manufacturer Part #:

BC547

Manufacturer:

Fairchild Semiconductor

Description:

Bipolar Transistors - BJT NPN 45V 100mA

Lifecycle:

upload_2016-9-15_8-37-0.pngObsolete



Mouser Part #:

512-KSC1815YTA

Manufacturer Part #:

KSC1815YTA

Manufacturer:

Fairchild Semiconductor

Description:

Bipolar Transistors - BJT NPN Epitaxial Sil
 
Hmmmm.. I know the 1815's I get from Mouser actually have that number printed on the side. It's so small I have to use magnifying loupes to see it, but it's there. Fantastic that you got it working. It's really satisfying when you wade through a mystery like this one and finally find the answer. :thumbsup:
 
Glad you found the problem.:thumbsup: I've yet to have Mouser mess up an order (knock on wood) but you can be sure I'll be double checking more now.

I think the advice you're going to get from most on this board is do not replace transistors unless there's something wrong with them or they're known trouble makers like the SC458's. It just invites more problems.
 
You must log in or register to reply here.
Back
Top Bottom