Hi, just checked with SONY Asia (HK).

Only HK SONY service center will accept your PS3. You'll have to send the set to a friend in HK for repair because SONY requires someone to receive and verify the repair. SONY actually discourages import sets because of such conflicts, so, it's advisable to buy local sets.

I've also checked with an experienced shop in Sgp. They have encountered many such cases (similar to yours) and there is still no method to fix it yet. But, the technician advised you to keep the set for the time being because there might be a way to repair it in the future.