Macintosh XL Boot Issue

[Mikemike690]

I've recently acquired two Macintosh XLs with asset tags on them and have managed to swap out all the boards to get one combination that works but when I boot it up I get this weird screen (attached) where it is split into thirds and it won't for some reason boot from the floppy drive, could it possibly be the boot ROMs? If so I have ordered some to reverse the Macintosh XL conversion anyway. Thanks in advance

http://i.imgur.com/EjrEPxQ.jpg

 

[bibilit]

Looks like it's just an adjustment issue in the screen side, had the same problem in an Apple IIc screen not long ago... but can be wrong.

 

[Mikemike690]

Oh okay, do you know how I adjust the screen there are a couple knobs above the analog board?

 

[ScutBoy]

Take off the top, and put the rest of the machine back together and turn it on. You can then adjust the pots on the little video board to fix the image.

 

[Mikemike690]

Okay gotcha, what pots do I adjust?

 

[ScutBoy]

I think they are marked on the PCB, but you may have to fiddle with each one to find the one you want.

You may want to mark the original positions with a marker or pen if you are able, but i don't remember really needing to do this.

 

[aplmak]

I recommend Larry Pina's Mac & Lisa repair guide... With my lisa's I make sure to recap the video board, power supply at least... I do all the other boards too but it's important to do the power supply and video board.. Also the trimpots usually crap out.. they don't make the proper contact after years of use or storage... You can order new ones through John W. and he lists them on ebay. The issue with yours is yes you need to adjust the trimpots... I forgot which one to adjust that fixes your issue, maybe 2nd to last on the right... It may flicker too because as I said the connectivity of them just craps out over the years.. Just be super careful... everything in there is HIGH VOLTAGE!!!!!!