SCPH-10000/SCPH-15000 causes screen to flash when another device is switched on/off

I've been using SCPH-10000 consoles since I got my very first one in 2010. All of them, would cause the screen to flash black (about half a second) and the sound will go out for that brief moment, whenever some other device (including the fluorescent-tube ceiling lamps) in my flat is switched on/off. But once the video and sound comes back, the console would continue running as if nothing happened.

I'm not talking about heavy machinery or heavy-duty appliances like the air conditioner (which is faulty here) and the fridge (probably too many rooms away to matter). I'm talking about small stuff like chargers for phones.

These consoles were made to run on the Japanese 100VAC 50/60Hz mains. The mains here is 230V 50Hz, so I've been using step-down transformers to run these consoles. I've measured the output from the 400W transformer that I'm using, and it measures about 118V before and during the lights are flicked on (with my SCPH-15000 and its HDD unit connected), so the output is stable.

I have a 60W PowerPac 220V->110V step-down too, so I connected my SCPH-15000 to it and still noticed the flashing whenever I flicked the lights switch in the room on/off.

The TV here is a Samsung LCD TV. These consoles were previously connected to the larger Samsung TV outside, so it's definitely not a TV problem.

Is this a known issue with these early consoles? I mean, does this happen in Japanese homes too? If not, what electrical property causes this?
This does not happen with any of the fat local sets here (SCPH-39006). I have the PSX too... but I don't remember this happening to it. I remember some flickering, but I think that it happens only at power-on (essentially, it felt different) and I didn't use it much either.

Also because I've lost 2 SCPH-10000 consoles to suspected clock generator failures, I'm now quite weary about this. I wonder if they are failing because of the heightened voltage here (~115V, via all the 220->110V step-down transformers that I've ever had) or because of some other difference in AC power here. Coincidentally, they both failed in similar ways, after about a year of use here.
So far, we've been blaming the failures on their age and perhaps because they were defective. But what if...?

 

When you switch a light switch on/off there is a spark from between the contacts that causes quite a lot of interference.

I just suspect less shielded for interference than the later models. The 115v vs 110v is well within spec, so I doubt any issue with that.

 

Mine don't do that even when I run the vacuum. Could it be 50/60 hz compatibility? Even the best stepdowns don't usually convert that and some devices don't handle that well.

 

Thanks guys for your input.

I just realized last night that perhaps the only things that affect this console are the ceiling lamps. As with most homes around here, they are fluorescent tube lamps. Doesn't anyone out there use them too?

I think that the idea that I had about phone chargers came from the experiments with the i.Link interface in 2011, when I used to connect a IEEE1394 enclosure to the SCPH-10000 console from that time. Whenever I flicked on/off the PSP charger that powered the IEEE1394 enclosure, the screen would flicker. But that was about 4 years ago lol.
Whatever it was, phone chargers don't affect this console.