4 replies to this topic

[MrSiggler]

Hey all.

I've got a broken Atari Lynx I'm trying to fix. I'm hoping it only needs a few parts replaced..

When I first got it, I put batteries in, flipped it over and tried to turn it on.. the power button didn't seem to work, the power LED wouldn't light up. But I noticed the screen *was* on, just really dim, saying insert game. So I turned up the brightness, and could see the screen fine. The off button wasn't doing anything, so I tried plugging the game in... the game did start. Audio played. It worked great (aside from the lack of power LED) for about 10 seconds, then it abruptly seemed to shut off... wasn't able to get any life out of it after that. (note, I noticed that all too familiar smell of burnt electronics shortly before it went black). So I hit these forums, and saw about the Q12 thing.. so tried jumping the headphone/battery thing.. when I did such, before I was able to flip the thing over to check for life, I noticed smoke coming out of it.. so I cut the power. On inspection, the part labeled Q8, I believe, had burnt/split in half. Obviously there's no point in my tinkering further at present

And now my questions! What parts are compatible with the Q8/Q7? Could that part be the cause of the thing not powering up/acting oddly, and would I be wise to replace the Q12 part as well? (assuming it might have caused the Q8/Q7 part to fry?) And if so, what part is compatible with that?

I've got a stack of PC motherboards which appear to have parts that look identical to these, but I'm not sure if they're compatible..

Many thanks for any info/advice!

[MrSiggler]

An update. I googled around and found a replacement part for the Q8 spot.. a transistor with "1AM" on the top. Swapped out the fried part for this, and after shorting the headphone/battery negative, still had nothing but a white screen. I tested various spots around the board for voltages.. it was 8.x volts, closer to 9v. Having read that anything that high would likely kill the board I assumed it dead, but decided to try feeding it 5V directly just to see for sure... wired up a USB cable to the battery posts and plugged into into a wall charger, and the game started!

I couldn't control anything though. I've discovered that the green coloured ribbon, the one for the front panel.. LED/buttons/so forth, seems to have been stripped of the black conductive film. I trimmed back the ribbon to expose more black, but it seems it's very brittle, and that new black came right off as well... I'm currently trying to rig up something to get this ribbon cable to work.

So I'm not sure if the Q12 is actually bad or not. If the front panel ribbon isn't working right, perhaps the power button presses simply aren't getting through?

So I think I'm dealing with two issues. The bad ribbon cable from the front of the Lynx to the main board, and the PSU area sending the full 9V into the board... any suggestions? I'd love to get this thing working!

[Sub(Function(:))]

circuit can be found here:

http://www.atariage....tics/index.html

Q usually denotes a "transistor", but there are two basic sorts npn & pnp (not interchangeable). Looking at the link above the transistors seem mainly 2n2906 & 2n3904. these should only be a few cents new from you local electronics shop.

Please make sure you get the pin alignment, these do not alway follow the same pattern.

[MrSiggler]

Thanks! I replaced the Q8/Q7 with the aforementioned "1AM" part, they seem to operate fine. By that, I mean the machine isn't smoking or doing anything peculiar, and the games do play.
Right now I'm left with two problems. The membrane has deteriorated over the years, and doesn't seem to work properly. The LED never lights up(the LED does work. I fed power to the membrane by hand and it lit up), and half the buttons don't work. Including the on button. (Hence my initial assumption that the Q12 was bad, but if I use the headphone trick to jump start the unit, the off button does turn the unit off, the reset button also works. I presume the Q12 mosfet is intact okay?)

For the ribbon cable/membrane I'm thinking I might be able to rescue it with a circuit pen, and/or some sort of conductive glue. Keeping my eyes open for a ribbon cable with the same spacing as this one to slap on the end.

For the power issue (it seems the full 9V of whatever power source is used it sent into the main board), I'll try slipping a 5V voltage regulator in there to safely reduce the voltage to 5V before the lynx's broken power circuit sees it. Has anyone done this?

[karri]

I would suggest that you get some broken Lynx and take the entire ribbon cable + LCD system from that. It is easy to find Lynx units with broken motherboards but with all the ribbon cables and LCD's in good shape.

At the same time you could slide in the LCD filter pack from a broken laptop or LCD monitor. It makes a big difference to the black level on the Lynx screen.

The flickering led is flickering on good units too. Don't pay attention to that one.
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Karri