SEGA Saturn shaky display & freezing between loads...

[retroborg]

Good day,
I have a EURO PAL SEGA Saturn Model 2. MK-80200A-50, ASSY CD UNIT JVC EXL-P605 & 32pin IC.
Games do load, but the screen is a bit shaky as if there is a sync problem. It is not possible to be caught on camera, but the problem is there. Also after some time and in between loadings, the display will go black, while the CD continues to spin and the console will stop responding until I reset it.

After visual inspection on the M/B, I don’t see anything that could be causing this problem and the problem persists even with different TV cables and various games.

Does anybody know what could be wrong with it and what I could do to fix it?

Thanks in advance

[Zak33]

possibly the TV screen frequency via Scart lead? Are you using a CRT?

I think my Sega Saturn liked to be at 50 hz even though my CRT was a 60hz screen.. think I had the option when loading.

[Ferral]

The shaky picture could be interference from something else in the vicinity, found this happens with my Spectrum which is connected via RF to a CRT display, same goes for my Amiga 600 at times which is connected to same TV via RF. Try and make sure that stuff like the power lead isn't touching the cable that connects the machine to the TV.

You could also try cleaning the lead connector with some isopropyl alcohol (or surgical spirits), clean the connector on the machine also, sometimes a bit of a rough dust build up can cause this issue as it creates static which in turn would make the picture go funny.

As for the loading issue, that could well be the lens on the machine on its way out. Inspect the lens and look to see if it is bleeding at all, you will have the main color which is usually a blue / green type color, look at the edges and see if there are shadows there creeping in over, worst one I seen was an old Playstation 1, around a quarter of the lens had actually gone a dull yellow color, needless to say the lens unit needed replacing.

You could try cleaning all the connectors to the ribbon cables inside the machine, soft brush (non plastic bristles model brush is what I usually use) and clean edge connectors after disconnecting lens etc once again using isopropyl or surgical spirits. Also carefully clean round legs on the chips inside the machine with soft brush and replace any glass fuses in there.

DO NOT use acetone which is readily available still in chemists, this actually damages connectors etc over a long term.

[retroborg]

So, it turns out that bad capacitors on the power supply will not provide the adequate filtering to avoid ripple on the DC output.
And apparently, it was a problem with the PSU. I changed it with another one and everything seems to be working fine now.

The letters on the screen (Especially the white ones) are still a bit shakier than the other 2 Saturns I own, but I'm not sure if recapping the motherboard will fix that. Anyway, the shaky display has been greatly improved with the new PSU, it's just not as stable as the other VA7 Saturn which I have.

In fact I've read that All VA9 boards are like that, and to a slightly lesser extent also VA7 PAL and VA13 PAL too. (Anybody care to verify that) and this so happens to be a VA9 board, while the other VA7 board has a more stable display.