Arg both my Ataris are broken!

[JingleJoe]

Friggen hell! Both my Atari 2600's broke this week

First my 2600 jr glitched out, the controlls behave oddly and the game sprites are a bit messed up along with some sounds. This is not as disapointing as it is interesting, however it is still disapointing but I am not worried about fixing it for now.

 

Secondly my big woody 2600 broke aswell! It was working fine a few days ago now it's got problems too the games play and control fine, however the image is shifted vertically, so the game screen is half on the bottom and half on the top of the screen, sometimes this scrolls and flickers about, additionally there is a horizontal a bar of interference accross the top of the screen and some other odd picture defects in the form of bars of mess and flickering.

Graphics and games behave fine, but the acctual picture output seems to be where things go wrong so I suspect that it has something to do with the RF output but I want your opinion too!

Does anyone know what could be wrong with it?

 

note: I use the same PSU for both Atari 2600's, there could be some defect with this so I tested it with my voltmeter and found it to be outputting 13.7 volts (2600 requires 9V) I know it's supposed to be a bit higher than rated but does anyone think that's a bit too much?

[Chandler]

Friggen hell! Both my Atari 2600's broke this week

First my 2600 jr glitched out, the controlls behave oddly and the game sprites are a bit messed up along with some sounds. This is not as disapointing as it is interesting, however it is still disapointing but I am not worried about fixing it for now.

 

Secondly my big woody 2600 broke aswell! It was working fine a few days ago now it's got problems too the games play and control fine, however the image is shifted vertically, so the game screen is half on the bottom and half on the top of the screen, sometimes this scrolls and flickers about, additionally there is a horizontal a bar of interference accross the top of the screen and some other odd picture defects in the form of bars of mess and flickering.

Graphics and games behave fine, but the acctual picture output seems to be where things go wrong so I suspect that it has something to do with the RF output but I want your opinion too!

Does anyone know what could be wrong with it?

 

note: I use the same PSU for both Atari 2600's, there could be some defect with this so I tested it with my voltmeter and found it to be outputting 13.7 volts (2600 requires 9V) I know it's supposed to be a bit higher than rated but does anyone think that's a bit too much?

 

the 9v PSU are never 9v when tested with a multimeter, i've tested loads and they are always about what you say 12 / 13v so the psu sounds ok

 

but if you have another try another seeing as both your Atari's have failed at the same time using the same PSU

[jamesk]

Chandler is right, the power supply will provide a bit more than 9v without a load because it is an unregulated power supply. FYI the 7805 voltage regulator (converts 9v to 5v) inside the 2600 can handle up to 35v. So even if you used a 13v power supply the 2600 would drop it to 5v with the left over 8v converted into heat. Which is a lot of heat for the heatsink inside the 2600 to handle, but the 2600 would still run at least until the 7805 hit a temperature of 125C and entered thermal shutdown.

[Geffersan]

Friggen hell! Both my Atari 2600's broke this week

First my 2600 jr glitched out, the controlls behave oddly and the game sprites are a bit messed up along with some sounds. This is not as disapointing as it is interesting, however it is still disapointing but I am not worried about fixing it for now.

 

Secondly my big woody 2600 broke aswell! It was working fine a few days ago now it's got problems too the games play and control fine, however the image is shifted vertically, so the game screen is half on the bottom and half on the top of the screen, sometimes this scrolls and flickers about, additionally there is a horizontal a bar of interference accross the top of the screen and some other odd picture defects in the form of bars of mess and flickering.

Graphics and games behave fine, but the acctual picture output seems to be where things go wrong so I suspect that it has something to do with the RF output but I want your opinion too!

Does anyone know what could be wrong with it?

 

note: I use the same PSU for both Atari 2600's, there could be some defect with this so I tested it with my voltmeter and found it to be outputting 13.7 volts (2600 requires 9V) I know it's supposed to be a bit higher than rated but does anyone think that's a bit too much?

 

Sounds like a power supply issue to me, its just very unlikely that your 2 fully working atari's would fail in the same week.

I've had very similar problems, a C64 that would work and then fail with randomly generated colored characters on screen and a snes that would only display a black picture.

The C64 power supply checked out fine when multimetered showing 5v dc and 9v ac but was faulty, this was confirmed by using a working power supply.

The snes power supply showed 9v dc (this changed to 14v dc after being fixed) but the system worked immediately with a different power supply.

In both cases the power supply filter capacitor had failed and the resulting voltage ripple was causing serious problems, they were both fine after i replaced the capacitor. (this involved cracking open the power supply so you might just want to buy a new one)

 

Hopefully your power supply hasn't overvolted and fried some of your ram chips.

 

I could be wrong of course but a new power supply is where i would start, get a regulated multi-voltage that can output 9v at least 500ma, the tip on the power connecter should be set to +

 

Good luck.

[JingleJoe]

I just broke open the power supply (I had to use a saw, it was fun ) the cap looks fine so I tested the output with my oscilloscopes and there was no ripple or fluctuation and the output was at about 12V still.

 

Surprisingly to me the PSU just consists of a transformer, diode bridge and capacitor so I was considering adding a voltage regulator but if it's just going straight to the 2600's internal voltage regulator does it really need one? Could the Atari's regulator be to blame? What on earth is wrong with it

[A.J. Franzman]

You need to test the output under load. Put something like a 22 ohm, 5 watt resistor across it then check for ripple again. Be careful, the resistor will get hot. Also, while watching the output from the DC plug, gently tug and flex the cable, especially near both ends, to check for internal breaks.

 

BTW, I have opened and fixed several original Atari wall warts using a hammer and SHARP wood chisel right on the original seam. After internal repair and reassembly using super glue, it's very hard to tell they were ever opened.

[JingleJoe]

Ah, I see, I thought one might have to test them in such a way but I am still learning, thankyou for all the tips and help I'll do that tomorrow, I have many nice power resistors.

[JingleJoe]

Bask in the green CRT glow of my fantastic oscilloscope

 

 

Thanks to Mr Franzman's advice about the load, the power supply ripple is found!

[JingleJoe]

Huzzah! It is fixed!

I built a new power supply from scratch, with a voltage regulator that gets a little too hot for my liking, so I might have to make some changes. I changed the capacitor on the original PSU but that didn't change anything so a brand new PSU was the way to go.

[Geffersan]

Huzzah! It is fixed!

I built a new power supply from scratch, with a voltage regulator that gets a little too hot for my liking, so I might have to make some changes. I changed the capacitor on the original PSU but that didn't change anything so a brand new PSU was the way to go.

 

Nice, at least it was only the power supply.