Retro Repair (attempt): Sega Saturn

Posted on October 3, 2016

Over the years I’ve gotten pretty comfortable tearing down and repairing electronics. When Blanco told me about his busted Sega Saturn MK-80000 (launch unit) I was immediately interesting in taking it apart and trying to find the issue. Sadly, sometimes the issues with older electronics are not fixable. This is my first Sega Saturn repair but it all seemed so straight forward.

The symptoms:

No audio/video and the power LED blinks on and off rapidly. There is also an audible “clicking” sound, which later I found out was the Power LED powering on and off – not the PSU itself.

The common solution:

After much googling, it turns out a lot of Sega Saturn units have capacitors issues. This isn’t synonymous with the Saturn and capacitors have a finite shelf life like all electronics. The console is 20 years old after all. There was a 15% failure rate with this model out the gate so it’s amazing Blanco’s lasted this long. So I headed over to mouser.com and order some capacitors.

The Outcome:

Sadly, it’s still dead. When I first visually inspected the PSU, the original capacitors all looked fine. Just because they look fine doesn’t mean they are so, as I said, I replaced them. I also tested to see if power was getting to the molex connector that chains the PSU to the motherboard. When the Saturn was plugged in after awhile, it would show signs of life again and the molex nodes showed the proper 3.3v, 5v, and 9v with some slight variance. Other times, the blinking power LED would come back and the voltage was all over the place but very very low. There are other parts on this console’s PSU that could be bad but is it worth replacing all the other elements? That’s up to Blanco and his wallet!

WARNING: Opening any electronic device with internal power supply can cause a deadly electric shock. If you do not know what you’re doing, please do not attempt this without learning the dangers and precautions first!

Here’s the part list from Blanco’s Model 1 MK-80000 (build date: April 1996):

(All Caps are manufactured by Nichicon)
200v 120uF – UCY2D121MHD
10v 4700uF – UPW1A472MHD
16v 2200uF – UPW1C222MHD
10v 2200uF – UPW1A222MHD
16v 47uF – UPW1C470MDD
16v 330uF – UPW1C331MPD (x3!)

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