2 power adapters?

[0078265317]

Was cleaning out the basement this past week and reorganizing.  Threw a lot of broken or unused stuff.  Kept most of the collection.  But in doing so I they out the box for one of my power adapters for the 5200.  Now I cannot remember which adapter is good and which is bad.  Not sure if either is bad but one was working for sure.  One is 9.3v and the other is 11.5v.  I have two four port systems.  1 asterisk and 1 without.  And one 2 port system.  They are interchangeable if I remember correctly.  But not sure if either is bad.  If I just plug it into the wall and use a volt meter the one I had in the box measured 14 something.  That is normal somebody here said.  Does that mean its good?  And if it was busted it would measure zero like the other one I had fixed?  So its safe to plug in?  Or is 14v too high?

[+-^CrossBow^-]

Yes...and no...LOL

 

The 14v output is normal yes and pretty standard for a 9v supply without a load on it. When plugged into the console it drops down to about 10v there abouts in most cases although on the 5200, it seems to only drop down to about 12v as measured on the input rails in most 5200s I've serviced. 

 

But to better answer your question, there are two main things that a PSU needs to provide for the console to work properly:

 

1. - we already just spoke of and that is the output voltage. In this case 14v is fine since the regulators inside the console are designed to take a higher voltage input and drop it down to the +5 the system actually uses. The more input voltage you give the regulators, the harder they have to work and give off that extra voltage as heat. So the closer to 9v input you can get, the better it is but 10 - 12v isn't unusual under load.

 

2. - is the output current. This isn't as easily measured without connecting the multimeter in line with the power output to the console so that you can see how much is being drawn from the entire system when powered on. The 5200 stock on its own is about 600 - 700mA on average from my bench power supply. The actual output current from the PSUs are rated at like 1.5 - nearly 2A if I remember? It is likely this was needed for eventual add on peripherals of which only the VCS adapter would get released, but more add ons would mean more current to power everything was needed so Atari seemed to be thinking ahead in that regard.

 

So yeah... you can get a PSU that provides the proper voltage but then do to some failing component inside it, it might not produce enough current and prevent the system from powering up properly or cause issues when powered on and playing games.

[john_q_atari]

From what I can recall my 4 port has 2 voltage regulators connected to a honking big heatsink. If your 5200 is anything like mine I'd worry about too little current before I worried about too much voltage. And my power supply also measures 14.4 volts unloaded.

[+-^CrossBow^-]

34 minutes ago, john_q_atari said:

From what I can recall my 4 port has 2 voltage regulators connected to a honking big heatsink. If your 5200 is anything like mine I'd worry about too little current before I worried about too much voltage. And my power supply also measures 14.4 volts unloaded.

All 5200s have 2 7805s inside them. Each one essentially handling half of the power requirements to the system. I replaced both of mine out sometime ago with DC-DC switching regulators so it only uses about 350mA when powered on I think? So because of those being installed, I no longer required the heat sinks and can use a lower current PSU if needed.

[0078265317]

I bravely tested both out just now and both work.  Good news.