SA-3000 phono board issues

[maxProview]

Hello, recently I have bought a Pioneer SA 3000, the power amp work fine, but the Phono board is out.

The Phono board uses 3 pairs of transistor 2Sa978; 2SC1919 2SA912.
2SA978 seem to be ok because the voltage at the base and emitter are in the specs.
All others voltage are out of spec.

I have tested the 1/2W and 2W resistors (R25; R26; R89) they have some sign of hot, but they are OK.
At the + of C64 for example, I don't have 28V but the same 17 pin voltage.
The ground of the board is ok.

I need help to find equivalent for 2SC1919 and 2SA912. Personnaly, i think to choose 512-KSC1845FTA and 512-KSA1220AYS.
What is your option about my board ?

Thank for your help !

 

[markthefixer]

the ksc1845 is fine.

the 2sa912 replacement is a bit more ticklish. It's for a class A output, with ~14 mA (0.014A) current. (Working against a 2200 ohm 1/2 watt resistor.)
the ksa1220 isn't a bad choice, but it has a 1 amp collector current, that's a bit high...


some choices:
512-KSA1142YSTU to-126 ecb 180v .1a 1.2/8w 200mhz 100-320hfe
512-KSA1381ESTU to-126 ecb 300v .1a 1.2/7w 150mhz 40-320hfe



use the 512-KSA1142OSTU a gain code of O(O = 100 to 200)
or the 512-KSA1381ESTU a gain code of E (e = 100 to 200)
both are in stock at mouser.
the 1220 can be used in a pinch, but since it's going obsolete, I'm also trying to populate this space with alternatives.

 

[maxProview]

Thanks for the response!
Based on your instructions, I'm going to use the following:

ksc1845 FTA -> https://www.mouser.fr/ProductDetail/onsemi-Fairchild/KSC1845FTA?qs=UMEuL5FsraDCmxWozTypUA==
512-KSA1142OSTU -> https://www.mouser.fr/ProductDetail/onsemi-Fairchild/KSA1142OSTU?qs=tAvf9WkFBTXAm9ZAWWhK4A==

Now have started the job I think I'll recap the phono board. I want to enjoy this power amp for a good while.

For the condensator, I'm going to dig into the Nichicon FG series. I have already used this product in my SA 8500mkII (for my humble opinion) with a good result!
I think, (if his test is good) not replace the Zener diode MZ-250 because I don't have information about his spec.

For the 2SA978, i think BC557B look great. https://www.mouser.fr/ProductDetail/Diotec-Semiconductor/BC557B?qs=OlC7AqGiEDmn70sgGqG08g==

I'll post some pics next.

 

[markthefixer]

GWF-114 c3 & c4 are ceanl caps, and thus require Nichicon UKL caps. Low Noise.

I'm not going to check the SA-8500ii service manual for special cap considerations.

 

[maxProview]

For the SA-8500ii i have made the job; what do you think about the BC557B, it's a good choice ?