Atari 400 power supply.

[Wildman7399]

I have lost my Atari 400 AC adapter. It requires 9v at 3.4A. I have a variable adapter that will do the 9V, but at 600mA. I don't want to try it and blow up my 400 that I've had since childhood. Anyone know the answer?

[jvas]

The 400 requires AC not DC. The amper is important! Don't use a PSU, which produce less then required!

[Joey Z]

you might have some luck checking instrument stores for a heavier duty 9VAC adapter. My brother had a MIDI keyboard that needed a 9VAC adapter, and he had been borrowing my 400 PSU until he found one at a music store. Also, I'm fairly certain the 31VA model is for the 800 and 400, but that there was also a 15VA model that would power the 400 fine (at least I never had issues). That would be about 1.7A.

[Paul Westphal]

DO NOT use anything but a Atari power supply. Get one at Best Electronics, or B & C Computervisions, $15.

[Joey Z]

DO NOT use anything but a Atari power supply. Get one at Best Electronics, or B & C Computervisions, $15.

Can I ask why a third party power supply would be a bad thing to use?

[Paul Westphal]

It just generally not a good idea. Just spend the money to get a brand new old stock one. I'm weary about used original ones, but they keep working...

[Joey Z]

It just generally not a good idea. Just spend the money to get a brand new old stock one. I'm weary about used original ones, but they keep working...

well, I asked why, and 'It just generally not a good idea' doesn't tell me any more than you already told me. There should really be no issue with a power supply as long as it is the right voltage and it meets minimum current specs. Finding an original PSU does guarantee that you get one that does, and that it will fit, but if you can find the same thing without the atari logo cheaper, and you can, then there's really no reason to not get the cheaper one. A transformer is a transformer, they don't often go bad or have issues.

[Paul Westphal]

That's just it - they are CHEAPER - Price and quality. I trust a new old stock PS more than anything recently made. When they do go bad, and they do, they will take some IC's with them. I have seen it happen many times. I was just suggesting ( in my humble, inexperienced opinion ) the best way to go.

[Joey Z]

That's just it - they are CHEAPER - Price and quality. I trust a new old stock PS more than anything recently made. When they do go bad, and they do, they will take some IC's with them. I have seen it happen many times. I was just suggesting ( in my humble, inexperienced opinion ) the best way to go.

but on the other hand, it's just a transformer... not really anything to go wrong, and they're pretty hard to screw up. I have NEVER seen the transformer go bad, on anything. never.

[tep392]

but on the other hand, it's just a transformer... not really anything to go wrong, and they're pretty hard to screw up. I have NEVER seen the transformer go bad, on anything. never.

It's more likely that the cables will fail on these old transformers. If they get moved around a lot or people unplug by pulling the cord instead of the plug (my wife is terrible about this), the wires will fatigue and break. I have one in my drawer that has a bad cord.

[Joey Z]

It's more likely that the cables will fail on these old transformers. If they get moved around a lot or people unplug by pulling the cord instead of the plug (my wife is terrible about this), the wires will fatigue and break. I have one in my drawer that has a bad cord.

yep, seen that happen. But my point was that there's nothing wrong with a third party transformer. The real issue with 3rd party transformers is trying to find one so you don't have to find an atari one, or pay extra for one at Best electronics or B&C. It's sometimes hard to make sure you get the right plug.

Edited May 11, 2015 by Joey Z

[+slx]

I don't think you need 3.4 amps for a 400. According to the FAQ there is a 400 power supply with just 1.7 amps, so the 2 amp power supplies available at music stores should be sufficient. As it's a simple AC transformer I don't know why you shouldn't use a new one rather than one that will be at best 25 years old.

 

Even for DC power supllies the little wall warts available from e.g. ABBUC seem to have no disadvantage compared to the huge bricks of yesteryear except for not providing extra warmth in winter.

[+bob1200xl]

Can I ask why a third party power supply would be a bad thing to use?

 

A third party power transformer isn't a bad thing to use, but a crummy third party transformer may be a problem. Transformers have a certain amount of isolation built-in. Bad things that happen on the primary (120v) side should not propagate to the secondary side where your tender Atari sits. Windings need to be properly insulated or you may get a short between the primary and secondary. The core needs to be properly wrapped and sealed or it may vibrate, cutting through the insulation, again inviting disaster to the secondary. The Atari transformer has a fuse in the secondary to protect the computer - does a third-party have one of the proper size and function?

 

So, how are you going to tell which is OK and which is higher risk?

 

 

Bob

[Joey Z]

 

A third party power transformer isn't a bad thing to use, but a crummy third party transformer may be a problem. Transformers have a certain amount of isolation built-in. Bad things that happen on the primary (120v) side should not propagate to the secondary side where your tender Atari sits. Windings need to be properly insulated or you may get a short between the primary and secondary. The core needs to be properly wrapped and sealed or it may vibrate, cutting through the insulation, again inviting disaster to the secondary. The Atari transformer has a fuse in the secondary to protect the computer - does a third-party have one of the proper size and function?

 

So, how are you going to tell which is OK and which is higher risk?

 

 

Bob

you're going to look back in your life, think of all the transformers which have ever failed that you know of, and realize it's not a big risk and the probability of you getting a lemon or a badly designed transformer is low. Switching power supplies, whole different story. but transformers I think they have the technique down pretty well.

[+bob1200xl]

Yes. Even a high-risk transformer has a low probability of failure.

 

We do know how to make good products - but, will we?

 

Bob