Thank you man! for those links that's for SA-210K model not mine SA-R210, a remote control model. I disassemble the unit, and found the internal circuit were totally different, such as SANYO LM7001 16pin PLL synthesizer working at 7.2MHz quartz crystal; MITSUBISHI M50720 408SP 42pin PDV display driver; SANYO LC6512A,LC6513A 4 bit uP controller.... There is no uPD 1703 as you found on SA-210K.

Now, the problem for me is how can I find a free down load of the service manuals for SA-R210? One for US and one for EU model to compare. Cause they sell the hard copy for 20 euro/dollar of each that I can nearly buy a vintage unit on the eBay.
Anyone has the idea to help, please...Frank