Need to repair a couple of XE's

[DocRotCod]

So I am trying to get a couple machines working and thought I would check with the group:

 

1) 130XE with solid blue screen. Have replaced the RAM, all major IC's (Pokey, Antic, GTIA, CPU, OS, Basic, MMU). Have not replaced Freddie.

Also on this 130XE, it is missing component at c27. Looks like a cap or something and was hoping someone would know what it is.

 

2) XEGS - Works all the way, except Missile Command runs like super speed. Bad OS ROM?

 

Thanks for any help!

[flashjazzcat]

C27 is a decoupling cap, 0.1uf I think. It's identical to its neighbour C28 anyway.

[DocRotCod]

C27 is a decoupling cap, 0.1uf I think. It's identical to its neighbour C28 anyway.

Thank you, do you happen to know what exactly I would need to order to replace it?

[DocRotCod]

Ok I programmed a new 27256 EPROM with XEGS OS and that fixed the XEGS. Just need to fix the 130xe now.

[flashjazzcat]

Thank you, do you happen to know what exactly I would need to order to replace it?

 

I think it's a 0.1uf ceramic capacitor. You could probably any non-polarised capacitor of this value.

[DocRotCod]

So I got into a mood and fixed a couple more units:

 

65XE with RAM errors. Desoldered old 'MT' RAM, installed sockets, installed new RAM. Works perfect.

 

600XL replaced missing Pokey

 

Removed Freddie from remaining 130XE and installed socket. Waiting on replacement IC.

[DocRotCod]

Replaced Freddie and still no joy. I started looking at the MMU and noticed that one of the legs, while not broken, was quite a bit shorter. I replaced the MMU and now she's alive!

[DocRotCod]

Going to start tackling a few 800xl and 600xl boards next.

[DocRotCod]

So although the 130xe is working it has some weird things going on with it. The graphics seem to kind of freak out and tear with a cartridge plugged in. Also, about every other reboot, there is the blue screen with the cursor in the upper left and it plays the sound you would normally hear if you pressed the start button while turning it on. This is without a keyboard even attached.

 

Any help on this one is appreciated.

[1050]

So although the 130xe is working it has some weird things going on with it. The graphics seem to kind of freak out and tear with a cartridge plugged in.

Screams dirty clock signal to me, for a long time now, I just

replace U18 LS08 with HCT08 and be done with it.

 

Also, about every other reboot, there is the blue screen with the cursor in the upper left and it plays the sound you would normally hear if you pressed the start button while turning it on. This is without a keyboard even attached.

Unpressed keys showing up might mean that the 4051 pair on

POKEY, U23 and U24 are playing to different drummer or

outright hearing a nonexistent conversation and speaking

back to that one. There is some history of these being

flaky at times too and replacement usually ends the

threads posted.

[DocRotCod]

Screams dirty clock signal to me, for a long time now, I just

replace U18 LS08 with HCT08 and be done with it.

 

 

Unpressed keys showing up might mean that the 4051 pair on

POKEY, U23 and U24 are playing to different drummer or

outright hearing a nonexistent conversation and speaking

back to that one. There is some history of these being

flaky at times too and replacement usually ends the

threads posted.

 

I appreciate the info. Today I spent some time on it and realized someone had repaired a trace on the bottom of the XE, but it was a trace that was intentionally cut by Atari at the factory. Removing the repair fixed the unit.

[_The Doctor__]

please show picture of the offending bit of trace repair.... and the model/ markings of the board for future repairs... if it happens once it happens again