Amiga 1200 crashing and freezing

[Merc]

Now THAT'S one I've never heard of!  Quite an odd solution, too!  What little I know about the real electronics of how computers work would lead me to believe that is an artifact of one of the 'timing errors' that are discussed for the 1D3,1D4,2B motherboards.

Well your description of the problem (lines working their way up the screen) seems similar to what would happen to his.. and it only happened on DBLNTSC/DBLPAL/other 31khz modes.  Why dropping the intensity down a bit helped, I don't know, but I think one of us read somewhere (Aminet probably) that this would fix it.

[orange]

So, that timing fixes (R118, E123c...) wont help me at all?


(Budgie REV -01 and -02
   Remove E123C and E125C from the A1200 motherboard
   Add 470 ohm pull-up at pin 43 of U2, ie the Alice chip
   Change R118 from 470 ohm to 220 ohm)

I don't know where to look for solution anymore :-(

[Hyperspeed]

If you buy an Amiga 1200 how can you tell what motherboard revision
you have?

:-o

[Piru]

Only the Alice corrupted video output bug doesn't crash the computer. In fact, it rarely even corrupts the viewable chip ram! It just causes all sorts of visual effects to be displayed. If you try to snapshot the screen while it's showing this effect, the screenshot looks normal.

Actually it never corrupts chip memory.

That sounds like the problem where if there were any colours onscreen that were full-white, ie 255,255,255, the gfx would get corrupted after a few minutes -- my brother's 1200 had this problem, but mine didn't.

Now THAT'S one I've never heard of! Quite an odd solution, too! What little I know about the real electronics of how computers work would lead me to believe that is an artifact of one of the 'timing errors' that are discussed for the 1D3,1D4,2B motherboards.

This is not the timer problem, but the Alice pb discussed above. There are even patches in aminet that patch all 255,255,255 colours to 254,254,254 to workaround the problem.

[Doobrey]

Hyperspeed wrote:
If you buy an Amiga 1200 how can you tell what motherboard revision
you have

It`s printed on the top of the motherboard, between the ROMs and the expansion connector.
Normally says something like ..
 CHANNEL Z
A1200 Rev 2B

If the A1200 hasn`t been put in a tower, then you`ve got the fun job of taking it all apart,removing the top half of the metal shielding to find it!

[PiR]

orange, MY BROTHER IN PAIN!!!!!!

I thought the Devil challenges only me with this problem.

If you will ever discover this PLEASE MAKE ANNOUNCEMENT IN ALL MAJOR TV CHANNELS ALL OVER THE WORLD! ;-)

As you can see I failed this and I'm now affraid to touch internal parts inside the box.

I think the problem is the power, mayby broken path somewhere. I'm very suspicious about PSU socket on the mainboard. From my observations the system (when cold) freezes during any graphical activity (printing text, drawing windows). However it is not related with CHIP ram, as I use BVision...

Good luck with your investigations. :-)