May someone help with the name of an ic that supplies audio to front and center speakers on Technics SA-AX530 ie ic602 on the circuit board. just name it lost mine

Not a good sign. There should be a click a few seconds after you turn on the unit. That says the output section is OK. If there is no click, you need repair. Perhaps only some fuses inside, but it could be worse.

Also make sure that the speaker switch is in the right position, like A, not A+B. Also the headphone jack can silence the speaker.
Make sure that ALL switches are in the right position.

Hi,

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Goodluck..

That would depend entirely on your unidentified subwoofer and what IT needs. The Receiver puts out a usable Subwoofer feed on an RCA jack. That would suggest an RCA Cable, huh?

http://exaudio7.netserwer.pl/allegro/technics/sa-ax530_2/sa-ax530_7.jpg

Hello,there is a chance that you have a damaged speaker and that the amp is ok. Check the unit with no speakers at all connected,if there is no overload displayed then its a bad speaker.

R91 is a 1K Ohm
M1 is FSDM0356

check for shorts on the speaker terminals

An amplifier should never be turn on without speakers, it will overload internally.
make sure speakers work and try again.

SA-DX750 (sister Model to SA-DX850). Showing error code F70, after a few minutes running. Checking the power rails revealed +5VA and +5VD, on the Digital Circuit Board 'A', dropping to about 2V, when fault occured. F5, T1A, on the Sub-Transformer Circuit 'M', was subject to occasional blowing. The problem was traced to an intermittent break, in the printed circuit board conductor, in the vicinity of Q1702 (+5VD regulator) collector, on the Digital Circuit Board 'A'.. Repairing this cured the problem. Note that removing F5 (above), or disconnecting CN702, CN1000A or CN904B, on the Digital Circuit board 'A', also causes this error code to be displayed. Failure of the audio output ICs, IC651 & IC801, is apparently the usual reason for this error code being dsiplayed, but it is worth checking the power rails viz. +/- 25V (Fuses F3 & F4, T6.3A, on Sub-Transformer Circuit 'M') +/- 55V, +/- 14V etc.

There is likely separate gain controls for your surround channels on this receiver and they are probably set at -10dB. Enter the setup menu labled "level" and increase the amount for each channel equally.

bad solder connections and or dirty controls.