Black Lines on Performa 400

[Octolingual]

What are these black lines that show up on my Performa 400?? I suspect it has to do with the VRAM, but idk if the module itself is bad, or the traces, or if it’s even the VRAM at all. Anyone have any ideas?

 

[Byrd]

VRAM! Any chance you've another module from another Mac to test?

 

[Octolingual]

VRAM! Any chance you've another module from another Mac to test?

Unfortunately no. I wish I did.

 

[Forrest]

Remove the red battery before it explodes. I’m fairly sure the computer will work fine without a battery.

 

[bobcat]

Remove the VRAM SIMM and see if it still has the problem. There is also VRAM on the board, so you don't need it.

 

[cheesestraws]

Remove the VRAM SIMM and see if it still has the problem. There is also VRAM on the board, so you don't need it.

Isn't the Performa 400 an LC II in disguise? If so, it does not have onboard VRAM: it came with a 256k VRAM SIMM, which could be upgraded to a 512k one. You might be thinking about the original LC, which could do monochrome without any extra VRAM.

 

[bobcat]

Isn't the Performa 400 an LC II in disguise? If so, it does not have onboard VRAM: it came with a 256k VRAM SIMM, which could be upgraded to a 512k one. You might be thinking about the original LC, which could do monochrome without any extra VRAM.

Yes, you're right

 

[joevt]

The first problem is a vertical white line, then 6 or 7 or 8 vertical black lines, every 16 pixels.
If the problem was a broken trace, then the lines would all be the same color (usually black) and appear across the full width of the display.
The lines appear at the left edge of the display. Is there some kind of transition there (hsync?) that causes a voltage problem (capacitance?) for the first eight groups of 16 pixels? Maybe it is a bad trace (the lines appears every 16 pixels) but it's not a broken trace (the lines disappear after awhile). What is the color depth set to?