Sega Saturn powers itself off

Hello to everyone.

I have a problem...

Just sold a modded first model Saturn to a customer.
Before selling I test everything if its working correct.

The customer now tells me after 2 weeks he played the Saturn, that the machine powers itself off after about 10 minutes of gaming.
You can imagine that he claims me to repair it, cause I had sold him a faulty console.

Sure it is not my problem after he plays it 2 weeks and it gets faulty, cause I don't know what he did with it, you know.
But, good person that I am, I said OK I will give it a repair for free, he only needs to pay the shipping.

I never had a Saturn that powers itself off, nor likewise behavior.

Any advise where I can start looking for this issue?

kind regards
DragoonC

 

Not seen that before either.

After the Saturn powers off what happens to get it working again ? Do you just turn it off and on again or does it need to be left off some period of time before you can start it up again ? Guessing its a power supply issue, run it with a multimeter attached to the power supply output and watch what happens.

 

x

 

That is weird, I had that problem with mine too, but I caused that problem due to faulty soldering.

Besides, it would really be helpful to find a part list, especially for the capacitors.

 

Dreamcasts would do something similar and the problem was that the pins connecting the power supply to the mobo would move just enough via thermal expansion to cause a reset, not power off completely. Bending the pins back a bit fixes it.

However, this is off completely. If you leave it sitting there will it turn itself back on? How quickly can you get it running after it shuts off? Thermal expansion is probably at fault here but there are a number of parts that could do it.

 

The Saturn won't turn on again directly, no resetting.
I have to wait a time and even unplug the current cable.
Sometimes it will start up again (when I press the power button) then and powers itself off under 10 minutes, sometimes it won't turn on again.

I would think it's a thermal expansion problem too, but couldn't find any bulked out or leaked cap, nor a heated up component that would cause this behavior.
I tested the input current and the output current to the mainboard, everything is there but suddenly gone when it powers itself off.

I really don't know where to search anymore.
Might there be a switching transistor or something that can cause this?
I heard from a couple of people that the components VR101 and CR101 can cause power problems...
And some said I should tweak the pot RV201, but I don't tweak anything till I know whats it for.
Anyone knows what the pot is for ?

 

oh come on, no one has any idea? :sorrow:

 

I only have my own V2. Is the PSU compatible ?
And the pot on the PSU, what is it for ?

I now tested the PSU of the V1.
I swapped the power "push-button" with a throw switch, so I can be sure it isn't the power button that loses contact after time.
The pot on the V1 PSU measures 127 ohms, still don't know what it's for.
The Saturn stays only 2 minutes in power state, i heard a buzzing coming from the front of the PSU before the Saturn switches itself off. Caps don't buzz, transistors or something will, am I right?

 

x

 

Cool, now the Saturn won't turn on.
Seems like the buzzing noise was a component going to Valhalla...

I think it was one of the transistors...

 

I had a PS1 that did this, It wasn't a conistent 10 minute thing, and sometimes it would just reset. It turned out to be a dry-joint in the power supply, I noticed it starting to crackle and spark when I plugged in the power ( I was sharing cables with another console) and one day just dead - a used PSU fixed it.

It might not be a component as such on the saturn - just a broken joint that opens when the console gets up to running temperature - almost impossible to track unfortunately due to the non-constant state of the problem.

 

I wish it would be like ur problem back then, but unfortunately I can say there is no cold solder joint oder something likewise.
The buzzing sound came from a component, but which one I can't see/ hear/ smell or even find with a multimeter (maybe I even don't know how!?)

 

x

 

I will do so, tommorow

 

here you go:
http://farm4.staticflickr.com/3751/9692893714_8c27afe64d_o.jpg

http://farm3.staticflickr.com/2836/9689654649_f5cba8ef3c_o.jpg

http://farm4.staticflickr.com/3822/9689653769_334480bb1e_o.jpg

http://farm6.staticflickr.com/5460/9689652957_e359ac5c28_o.jpg

http://farm4.staticflickr.com/3757/9689652145_3fd39c6610_o.jpg

http://farm4.staticflickr.com/3798/9689651389_010424077a_o.jpg

http://farm4.staticflickr.com/3686/9689650705_08a28d10c2_o.jpg

 

There's no such thing as V1 and V2. Use the Sega designated VA numbers.

It does sound like a PSU problem - I assume you checked what you're getting out of the PSU? Pretty much standard PSU fault-finding from here on, then... or replace.

 

Sorry, I never seen a V2 with top mounted psu, so I said V1 psu.
I can't measure the outputs, cause the psu shuts completely off.
I read an article about how to find faulty components in psu's on the behavior of the psu.
A psu only shuts off if a transistor or diode is broken, otherwise the fuse would blow.

 

x

 

Touch the primary with your finger, then tell me the PSU is completely off (that's a joke - DON'T!!)

What I said still stands - basic fault-finding. The first thing you do is measure the outputs - you CAN do that even if the thing is off - you'll get a reading of 0 volts. Then test other stages of the PSU to find out where it's failing. Pretty simple stuff. Incidentally, a fuse blows because the circuit is drawing too much current (or there's a short). And yes, checking diodes and transistors is another stage of fault-finding.

What you said isn't strictly true, though. Electrolytic capacitors can cause problems, so they shouldn't be ruled out... although shouldn't necessarily cause complete failure alone. A diode breaking down under load will be hot to touch... although it may have measured fine when cold. And, of course, there could be a transformer issue.

I would suggest taking it to someone who knows what they're doing - try your local television repair shop.

Regarding model numbers, THERE IS NO V1 AND V2. Internally, there are far more than two variants of the Saturn.