Mac SE/30 Semisimac 128mb RAM

[xreactx]

Can anyone assist with overcoming the Semisimac pattern when installing 128mb RAM. I don't get the pattern when I have 64mb installed, but adding the additional 64mb creates the issue. I am running in 32bit mode. The Mobo has been recapped and works great otherwise.

 

[mikes-macs]

Just give it more time to boot as the memory test takes a while @ 128 MBs.

 

[xreactx]

Just give it more time to boot as the memory test takes a while @ 128 MBs.

I've had it own for several minutes without luck...

 

[xreactx]

On***

 

[mikes-macs]

I have 8 16 MB OWC 30 pin SIMMS in my SE/30 works great. But the first set I bought were some other brand from a seller on eBay and they did not work.
I also have an SE/30 board that has loose or bad solder at Bank B so only Bank A can be used at this time.
Do you have any other SIMMS to test in Bank B while Bank A has 4 16 MB SIMMS?
Both of my SE/30s have that Semisimac pattern when they don't like the current memory configuration, and/or when going thru the memory test.

 

[Phipli]

Have you tried both sets of 64 one at a time. Do both sets work on their own in the same RAM bank?

Clean the contacts on the RAM SIMMs carefully, and spray contact cleaner in the RAM sockets.

 

[xreactx]

Have you tried both sets of 64 one at a time. Do both sets work on their own in the same RAM bank?

Clean the contacts on the RAM SIMMs carefully, and spray contact cleaner in the RAM sockets.

Yes, each set of 4 work by themselves. I cleaned everything well. I had 8mb total on all slots before the upgrade and they worked.

 

[Phipli]

Yes, each set of 4 work by themselves. I cleaned everything well. I had 8mb total on all slots before the upgrade and they worked.

The 8MB in all slots isn't as informative because 8MB doesn't use all of the address lines so it isn't testing every pin.

Sounds like you have a dirty contact or damaged trace to one of the higher order address lines.

 

[techknight]

or the muxes are bad on the high order addressing. Common problem.

 

[xreactx]

Yes, each set of 4 work by themselves. I cleaned everything well. I had 8mb total on all slots before the upgrade and they worked.

Contact cleaner used to clean everything. Did not work. How do I check the address lines or "muxes"?

 

[imactheknife]

or the muxes are bad on the high order addressing. Common problem.

Hey Techknight, is this a mux issue? Board works perfectly after i get past the nasty horrizontal lines. It will chime about 10 seconds after i turn it on and get normal screen. Not sure if this is the same as OP or not. I tried different rom, ram, all banks work. Sorry to hijack. Just trying to see if it is something i can fix

 

[techknight]

nah thats not normal, but thats oddball...

Woudlnt surprise me if theres an intermittent via