Atari XEGS help (start button)

[sdond13]

Hi all.

I'm completely new to the 8 bit line.  But I found a good deal on an Atari XEGS today.  I brought it home and plugged it in and each get cart seems to boot.  But the start button won't do anything.  Somehow it once went to a ram test page and two rows of ram were green and two were red. I can no longer get to that screen, as when I can get to the test screen, I can't push the start button to select anything.  Bug hunt worked as I could start it with the light gun.  Does anyone have ideas on where to begin diagnosing? 

Thanks in advance!

[mimo]

Hi, 
The start button is a microswitch on the motherboard, my suggestion would be to open the case and check that the tab on the button is not broken and makes contact with the switch 
If that is not the issue, then spray some electrical contact cleaner on the switch and press it a hundred times or so, if it's still not working then swap the switch for a new one this will require some soldering though 

 

I have highlighted the switch in yellow on this picture of the motherboard 

[sdond13]

Thanks for the suggestion.  I took the top off and turned it on without the top.  The other switches still worked but pushing on the start switch itself did not.  I don't have any contact cleaner, and unfortunately I live in the middle of nowhere and about to experience a blizzard the next two days.  I put a drop of 91% alcohol on the switch and pressed it a bunch of times.  I'm going to let it dry for a while and try running it again.  Looking at the board it looks like everything is in good shape.

[mimo]

If you are feeling brave you could just use a piece of wire to close that start switch momentarily just so that you can start the self test, you would definitely prove that the switch is at fault then.
You might find a suitable part in some other piece of discarded electrical junk you have laying around, they are nothing special 

 

Do you have the keyboard add on? What happens when you plug that in?

[sdond13]

Do you just touch a single wire to each side of the switch?  Plugging it in again didn't help.  What's strange is if I hold start down during powering on it will go to the test page, but I still can't select anything.  Not holding it will bring it to missle command.  It did not come with the keyboard.  I was thinking about getting a ps2 adapter sold from the brewing academy.

[mimo]

Yes, just briefly short out the switch, but don't blame me if you get it wrong 💥

[xrbrevin]

hold down option when you boot without a cart for self-test

there is a keyboard test included

[Wilheim]

Hi, all!

 

I also have a XEGS with 4 switches going wrong. Does anybody know about a good remplacement for those switches?

[mimo]

3 hours ago, Wilheim said:

Hi, all!

 

I also have a XEGS with 4 switches going wrong. Does anybody know about a good remplacement for those switches?

 

[AtariLeaf]

Are these buttons the same as the 7800? If so Console5 carries them https://console5.com/store/tactile-switch-12mm-x-4-5mm-atari-7800-power-pause-select-reset.html

[seastalker]

Ah, I remember that thread well.  You may want to try to get exact replacement micro-switches. Have you tried Best Electronics?  You have to have a minimum order but you should be able to find some other fun things there.  Now that I am getting good with my desoldering gun, I may attempt an upgrade to it like another U1MB ram project or dvi/hdmi.

[AtariLeaf]

Yes I was wrong above, the switches you want are from Best Electronics not console5. I replaced the 2 switches on my XEGS a couple years ago. Simple solder job and it was good as new