Atari Ar-2 power Issue

charmer37

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Hello, I'm having a little issue with my Atari Ar-2 boards. I'm getting a very low reading from my meter like 0.49 on 1 Ar and 0.34 on another, Any answers is to why my voltage is so low and what can i do to repair the problem? Could it be the bridge rectifier and or big blues? If I wanted to convert to a switching power supply how can it be done? Thanks.
 
Hello, I'm having a little issue with my Atari Ar-2 boards. I'm getting a very low reading from my meter like 0.49 on 1 Ar and 0.34 on another, Any answers is to why my voltage is so low and what can i do to repair the problem? Could it be the bridge rectifier and or big blues? If I wanted to convert to a switching power supply how can it be done? Thanks.

With or without your pcb hooked up? Without a pcb the reading is crap.
 
My game was playing fine and all of a sudden i lose all power, The fuse is not blown and i did test the Ar-2's with the boards unplugged. I can plug the boards back in but their not getting any power? Thanks.
 
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Your voltages without the PCB plugged in should be roughly the same as what they will be with it plugged in. If not, then there's a problem.

You want to first check the voltage at the 10.3V test point on the AR, without the game board plugged in. This should be in the range of 12-13V DC. This is the input to the AR, coming from the brick. If you do not have 12-13V here, then the problem is with the brick, and it's most likely the bridge rectifier.

If you do have 12-13V going into the AR, and not +5V out, then the most likely problem is a bad 2N3055 transistor, which is the big one in the middle of the heatsink. Replace that first.

If that doesn't fix it, you should then replace the LM305 regulator (the 8-legged can-looking thing). One of those two things will almost certainly fix it.
 
Your voltages without the PCB plugged in should be roughly the same as what they will be with it plugged in. If not, then there's a problem.

You want to first check the voltage at the 10.3V test point on the AR, without the game board plugged in. This should be in the range of 12-13V DC. This is the input to the AR, coming from the brick. If you do not have 12-13V here, then the problem is with the brick, and it's most likely the bridge rectifier.

If you do have 12-13V going into the AR, and not +5V out, then the most likely problem is a bad 2N3055 transistor, which is the big one in the middle of the heatsink. Replace that first.

If that doesn't fix it, you should then replace the LM305 regulator (the 8-legged can-looking thing). One of those two things will almost certainly fix it.
The Brick is definitely a big possibility? I have a new bridge rectifier and i wanted to ask should i buy a new set of big blue capacitors? My voltage was very low and couldn't power my game back up.
 
The Brick is definitely a big possibility? I have a new bridge rectifier and i wanted to ask should i buy a new set of big blue capacitors? My voltage was very low and couldn't power my game back up.
I have low voltage readings on both of my Ar-2's.. Something like 0.54 and 0.34 when testing the voltage.
 
The reason I test AR2's with no load is a bad LM305 will regulate 5V correctly under no load.

You need to just go through the process, find otu if you have 10-15V on the big blues

make sure that voltage is getting to the AR2. find out if the AR2 even produces 5V without load. put the game in and recheck.

If it gets 5V with no game installed but falls to 0V or close to it with the game in. Its probably the lm305.

If you don't have power at all. Check fuses first, check the fuse holders too.
 
The reason I test AR2's with no load is a bad LM305 will regulate 5V correctly under no load.

You need to just go through the process, find otu if you have 10-15V on the big blues

make sure that voltage is getting to the AR2. find out if the AR2 even produces 5V without load. put the game in and recheck.

If it gets 5V with no game installed but falls to 0V or close to it with the game in. Its probably the lm305.

If you don't have power at all. Check fuses first, check the fuse holders too.
I just tested my 10.3vdc input on the Ar2's and its a low 2.12 reading.
 
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