Macintosh LC randomly lost color

[ExplorerZ]

I have been using my Mac LC once every few days, and today when i went to turn it on the color was gone. Everything is B&W and i can no longer change the color of the display. Any ideas on what’s happening? I tried reseating and cleaning the ram and vram, and booting the mac from a hard drive instead of my bluescsi.

 

[ExplorerZ]

Maybe it’s time for a recap

 

[olePigeon]

If it hasn't been recapped yet, I'm surprised you haven't had any additional problems. LCs always need a recap. The most common issue is squealing from the speaker.

 

[robin-fo]

Is the battery still good? Did you already recap?

 

[ExplorerZ]

I have not recapped it yet since i’m working on recapping my SE right now but i replaced the pram battery.

 

[finkmac]

if you haven't recapped an LC you absolutely should not be powering it on. you should be getting those old leaky capacitors off the board ASAP.

 

[joevt]

I have been using my Mac LC once every few days, and today when i went to turn it on the color was gone. Everything is B&W and i can no longer change the color of the display. Any ideas on what’s happening? I tried reseating and cleaning the ram and vram, and booting the mac from a hard drive instead of my bluescsi.

B&W or grayscale? Do you still have color options for the display in Monitors control panel?

 

[jovianartifact]

If an LC has no color, would it just be a Macintosh L?

 

[adespoton]

If an LC has no color, would it just be a Macintosh L?

No, because the C stands for Cost, not Color

 

[jovianartifact]

Ohh I thought it was Low-cost Color.

 

[cheesestraws]

Agree with @joevt, can you show us what the monitors control panel looks like?

The LC I (and only the LC I, no future LC) has a kind of weird mode where it can do 640x480 monochrome using RAM as framebuffer if it thinks it hasn't got any VRAM. So if you can only do monochrome, it may be that it's either unable to detect VRAM, or the VRAM you have in it is dodgy. But if it's not recapped, you should do that first and make sure the board is clean.

 

[croissantking]

Ohh I thought it was Low-cost Color.

I’ve heard it referred to as both

 

[Durosity]

Let's start a petition to have it officially changed to LCC (Low Cost Colour) and force Apple to recall all units for a re-badging.

 

[jovianartifact]

Let's start a petition to have it officially changed to LCC (Low Cost Colour) and force Apple to recall all units for a re-badging.

“Oops, this plastic is too brittle, better do a new production run”

 

[LaPorta]

Also, if the PRAM battery is not installed, it will default to B&W every time it is turned off.

 

[dan.dem]

The LC I (and only the LC I, no future LC) has a kind of weird mode where it can do 640x480 monochrome using RAM as framebuffer if it thinks it hasn't got any VRAM. So if you can only do monochrome, it may be that it's either unable to detect VRAM, or the VRAM you have in it is dodgy.

So this is interesting. After owning a Mac LC for nearly 35 years finally a new feature I learned from you. Thank you @cheesestraws !
Maybe this was one of the cost saving features for schools that was never used because it didn't save much money.

But I wonder if this feature may be something like a compatability mode for early applications designed for working with the original compact Mac's video/memory management. It also uses system RAM. However I never really understood its workings.

I really would like to try out this monochrome video mode since I also have a 12 inch Apple Monochrome Display which should do the trick.
Normally, with 256kB of video RAM installed it can do 16 grays at 640x480. (Actually if you are willing to really torture your flyback transformer it can even display 800x600 with the flyback literally screaming for mercy ).

Sadly my LC is not working right now.

 

[zigzagjoe]

The monochrome mode is interesting, I did a little digging on it a year ago. It won't work without a special VRAM SIMM: per the LC developer note a SIMM with a couple 373 latches is required, but I was not able to find any info pointing to one of these existing in the wild.

No more specifics are available that I could find. Plainly it must need to get the data from the system data bus to the video data bus. Not clear what signals they'd use for the OE and LE on the 373s, or if a sense pin is required.