Replacements for SA1941 and SC5198

[staze]

Hi All,

Repairing an Onkyo receiver. Shorted output transistors. Both an SA1941 and SC5198, which are obsolete. Interestingly, the schematics for the device list Sanken 2SA1695 and 2SC4468, which can be had. But some other threads have indicated to use Fairchild FJA4210OTU and FJA4310OTU. Anyone got any opinions on which? Price is comparable, the biggest diff is Digikey sells the Sanken's, and Mouser sells the Fairchild. Specs look similar enough.

 

[patrick101]

Since Onkyo is a Japanese brand, so that the output transistors P/N should be Toshiba 2SA1941 and 2SC5198 (140V, 10A, 100W, TO3P package).

You can use Sanken 2SA1695 and 2SC4468 with same electrical spec to replace Toshiba. For convenience to buy, some higher voltage and power output transistor of the same TO3P package also can use, like On semi NJW3281/NJW1302, NJW0281G/NJW0302G.

 

[staze]

Thanks Patrick. It’s interesting the build and schematic differ on the part used.

Mouser carries the NJW0281G/NJW0302G series. Any input on preference between them all? Fairchild, Onsemi, or Sanken? The higher current rating of the Onsemi is nice. Ultimately I think this thing just overheated, so running a higher current transistor at a lower current _should_ increase it’s expected lifespan.

 

[patrick101]

for power transistors, you can use Fairchild, Onsemi, or Sanken depend on the source, with same electrical spec or higher spec make no big different.

 

[vasillis]

staze how many pairs of 1941-5198 you want?

 

[staze]

staze how many pairs of 1941-5198 you want?

Only one pair is dead, but I probably should either replace them all (there's 7 pairs total), or have some on hand if another pair bites the dust. So, I don't know. lol. Do you have some laying around?

 

[patrick101]

Only one pair is dead, but I probably should either replace them all (there's 7 pairs total)

Actually you don't need to replace all power amp module together.

e.g., if one surround channel dead, you can remove the center channel power transistors to repair the dead channel to keep the surround channel balance and change the center channel (only one channel output) with different brand power transistor, you will not feel any big different in listening.

 

[vasillis]

Only one pair is dead, but I probably should either replace them all (there's 7 pairs total), or have some on hand if another pair bites the dust. So, I don't know. lol. Do you have some laying around?

i have a few. send by PM your adress.
you dont need to replace all of them.i send you 2 pairs for free.


BR

 

[staze]

Finally got these replaced, only to have no output. Need to troubleshoot further and see if maybe it's the DSP issue these things have, or something else.

Thanks @vasillis!

 

[big---mak]

Haha, doing the exact same repair (flashing red light on onkyo tx-sr577) and didn't realise 2SC5198 and 2SA1941 are a pair

 

[big---mak]

As far as I understand these are equivalent but would it be fine to mix different brands? I can only buy 2SA1941-O in 10+ quantity but I am able to find some of the others.