sony HST-550W service manual question???

[dmx2020]

Hi guys,

There appears to be an error in the service manual of this stereo. It is found here: SONY HST-550W E SM Service Manual free download, schematics, eeprom, repair info for electronics

On page 24, the STK IC (main audio IC) is given as the STK4131ii,

but

on page 32 and 45, the STK IC is given as the STK4152ii.

See the attached photos. So what is the corrct IC for this stereo? STK4131ii or STK4152ii ?? ??

Thank you in advance!

[dmx2020]

Heres some more info:

The HST-550W is rated with:

25W + 25W continuous RMS power (6 ohms, 1 kHz, 5% THD)
Peak power output: 350W
Total power consumption: 75Watts


Now the STK4131ii (from the datasheet): 20W + 20W (8 Ohms, 20-20kHz, 0.4% THD)

And the STK 4152ii (from the datasheet): 30W + 30W (8 Ohms, 20-20kHz, 0.4% THD)


Also the HST-750W (next model up) is rated at 35W + 35W RMS and it has a STK4141ii (which has 25W +25W from the datasheet)

And the HST-950W (next model) is rated at 50W + 50W RMS (power consumption 130W) and it has a STK4182ii (which is 45W + 45W from the datasheet)

Hope this stuff helps with the answer to the previous post. I really need to know the correct IC as Im replacing the STK IC of the HST550W and the existing IC is missing from the PCB!!!

[dmx2020]

I have solved my own problem Solution for anyone following in the future is below.

The correct IC for the HST-550w (E model) is STK4152ii.

The correct IC for the HST-550w (AEP/UK model) is STK4131ii.

So it seems there are different ICs for the same sony product in different regions. The E model is rated as 350 peak watts (STK4152ii) and the AEP/UK model is rated as 25w+25w rms (STK4131ii).

Confirmation can be found in the Service manuals:
AEP/UK model is here: Sony HST-550W Service Manual PDF Download

E model is here:
SONY HST-550W E SM Service Manual free download, schematics, eeprom, repair info for electronics

Cheers!