Cube 68030 Scrambled video on boot

Hi
I have a 68030 Cube with booting problems. After I replaced the caps, the cube starts to a scrambled screen and the red LED on the board is flashing 4 times fast. I also replaced the RAM and the CPU without luck. Does anyone have the electrical schematics of the 68030 board, or any idea how to solve it? The problem could be the nvram chip?
This board was previously stored in a box for 20 years, I don't know if it was working.
Here the screen at boot:
(https://postimg.org/image/h2gjvdjvn/)

Here are the LED code descriptions:

LED Blink Codes (LED on the logic board if system can not boot to ROM)
1,2     ROM CRC check failures
3       Bad VRAM
4       Bad NVRAM (The NVRAM store in the clock chip)
5       No usable DRAM


Try removing the battery and reseating the ROM chip. Did you desolder the CPU? I've never seen a socketed 68030. There are no schematics for this board.

Quote from: "barcher174"Here are the LED code descriptions:

LED Blink Codes (LED on the logic board if system can not boot to ROM)
1,2     ROM CRC check failures
3       Bad VRAM
4       Bad NVRAM (The NVRAM store in the clock chip)
5       No usable DRAM


Try removing the battery and reseating the ROM chip. Did you desolder the CPU? I've never seen a socketed 68030. There are no schematics for this board.

Thanks for codes Brian.
Sorry for the mistaken, I was wrong to write. I also replaced the RAM and the ROM (NOT the CPU) but I did not have luck... :oops:

My experience with these symptoms has unfortunately not been good. I've seen this with bad CPU's and with bad NeXT ASICs. Both require a significant amount of effort to rework. If you don't have an emotional attachment to the board it may be easier to buy a new one. You can see an example here:

http://www.nextcomputers.org/forums/viewtopic.php?t=3875&highlight=led+code

Quote from: "barcher174"My experience with these symptoms has unfortunately not been good. I've seen this with bad CPU's and with bad NeXT ASICs. Both require a significant amount of effort to rework. If you don't have an emotional attachment to the board it may be easier to buy a new one.

Thanks for your support, I'm not particularly attached to this board so if the replacement of the MC68HC68 Real-Time Clock (a SO16L chip) will have no effect, I'll look for another motherboard.
Does anyone have a working 68030 board to sell at a reasonable price?  :mrgreen:

Hello Krazycat: I've had that happen with non compatible ram, try putting the old ram back in.... I have a 68030 25Mhz for $99 or with new professionally replaced caps   $164 , tested / compatible ram $1 a mb in sets of 4. Also which version of the rom did you use as 030's tend to be finicky? Best regards Rob Blessin

Quote from: "Rob Blessin Black Hole"Hello Krazycat: I've had that happen with non compatible ram, try putting the old ram back in.... I have a 68030 25Mhz for $99 or with new professionally replaced caps   $164 , tested / compatible ram $1 a mb in sets of 4. Also which version of the rom did you use as 030's tend to be finicky? Best regards Rob Blessin

Hi Rob, for testing I used RAM and ROM Release 1.1 from a working 030 cube from a friend of mine. Thanks for your offer, if after the last tests my board will not work, I will write to you to buy a $ 99 board.

Quote from: "krazycat"
Thanks for your support, I'm not particularly attached to this board so if the replacement of the MC68HC68 Real-Time Clock (a SO16L chip) will have no effect, I'll look for another motherboard.
Does anyone have a working 68030 board to sell at a reasonable price?  :mrgreen:

This story has a happy ending: I had the MC68HC68 Real-Time Clock chip replaced, and now the cube works!

(https://postimg.org/image/snabo0r03/)

(https://postimg.org/image/70vb7005f/)

Nice work!

Very good! And good to know another fix for our beloved NeXT's.

And now to complete this cube, I have to find a power supply and a backplane (this revived motherboard has been tested on a friend's cube)  :D

Hello: I have a working NeXT Cube model 152 power supply for $99 and internal backplain for Used $20 or $30 New Old Stock, do you need the drive harness as well $25?  Best Regards Rob Blessin