LC2 Sad Mac chime after recap

[crazyben]

I recapped the board. And I am getting sad Mac chime. I removed the DFAC chip and cleaned it. What else can I check to troubleshoot this?

 

[DJ68K]

Is C2 hooked up at the top of the picture? Looks a bit shifted towards the rear of the board. Otherwise, what's the exact hex code underneath the Sad Mac? Knowing that can help troubleshoot where to look on the board.

 

[crazyben]

Yes it is hooked up. Just the picture angle looking that way. There is no hex code. Just white screen with sad Mac chime on start up.

 

[crazyben]

I did noticed that one of the pins on the cpu was bent and was touching another pin. I separated it now. But still same issue. Does this mean that cpu is gone?

 

[joshc]

Are you testing with no VRAM (Video RAM) SIMM installed? There is no onboard VRAM so I believe you need a SIMM installed to get video output, though I wasn't aware this results in a Sad Mac though maybe it does. Could be dealing with two issues here. White screen is indicative of something not right on the video side, though.

Touching CPU pins wouldn't have been helping but it should be OK now.

From the LC II developer notes:

Video data is stored in a video RAM (VRAM) SIMM. The Macintosh LC II can be
configured with either 256 KB or 512 KB of VRAM. With 256 KB of VRAM
installed, the following video modes are supported: 512 x 384 monochrome or 8-bit
color on the 12-inch RGB monitor, and 640 x 480 monochrome or 4-bit color on the
13-inch RGB monitor. With 512 KB of VRAM installed, the Macintosh LC II also
supports 16-bit color on the 12-inch monitor and 8-bit color on the 13-inch monitor.

 

[croissantking]

I did noticed that one of the pins on the cpu was bent and was touching another pin. I separated it now. But still same issue. Does this mean that cpu is gone?

You shorted DS to Ground, no big deal I wouldn’t have thought.

I see some of the other pins 117-122 are slightly bent - perhaps it would be worth straightening them (if not already done) and checking continuity to the pads. Something gave this CPU a nasty bump.

 

[crazyben]

I tested this with VRAM. Just the pic is without one. I even swapped working VRAM from LC to rule that out.

Are you testing with no VRAM (Video RAM) SIMM installed? There is no onboard VRAM so I believe you need a SIMM installed to get video output, though I wasn't aware this results in a Sad Mac though maybe it does. Could be dealing with two issues here. White screen is indicative of something not right on the video side, though.

Touching CPU pins wouldn't have been helping but it should be OK now.

From the LC II developer notes:

 

[crazyben]

View attachment 62489
You shorted DS to Ground, no big deal I wouldn’t have thought.

I see some of the other pins 117-122 are slightly bent - perhaps it would be worth straightening them (if not already done) and checking continuity to the pads. Something gave this CPU a nasty bump.

There was another pins that was touching I fixed that and all other pins are fine.