C070243 REF F 4MB Upgrade Questions

[paulhocker]

It just occurred to me that I have not done the RAS0 mod by adding the resistor yet. Would that cause the issue of missing ram?

I think it is probably one of my solder joints or one of the connections to the CAS1 lines.

[paulhocker]

As an experiment, I disconnected the RAS1 connection, and it still showed 2MB. So, I am going to recheck the solder joins on the 4 connections to the motherboard to see if that does anything.

I really don't want to check all my solder joints quite yet on the ram board, but obviously I have not ruled that out yet. Some of those ground pins were hard to flow TBH.

[paulhocker]

Another silly question maybe.

Because it still showed 2MB with the RAS1 connection out, does this mean that I do NOT need to make the RAS0 resister mod to the MMU, or is that still possibly the problem with the install?

[paulhocker]

Just adding another post to see if anyone has any thoughts as to where I should begin troubleshooting the second bank of ram that is not showing up.

Thanks.

[DoG]

RAS1, CAS1L and CAS1H is all needed for the bank 1 (upper) to work. MAD9 is also needed of course, but that seems ok since you got 2Mb working.

The resistor mod is only needed to get a reliable ram but it should work without it. Since it is used for lower bank 0 it has nothing to do to get bank 1 working.

Check that the cables don't bridge with other stuff on the board. Bridges and solder whisker is easy to get if you are not using flux. Can you take photos of your installation and how the cables are connected?

[paulhocker]

Thanks @DoG

Here are some pics. Let me know if they are too blurry and I can try a different way.

Thank you for confirming that I do not need to resistor mod, so at least I know Bank0 is 100% working.

Is there anything on the daughter board that i should be looking at? Obviously the connections for the wires will need to be checked for continuity.

Thanks.

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[DoG]

I would try and solder the RAS1 wire (orange) to R135 location instead. Under the green wire. The left side on the photo doesn't have any traces to them. It seems wrong.

[paulhocker]

Update:

THAT WAS IT!!!!

I moved the RAS1 connection to R135 and it is working perfectly now.

@exxos perhaps a mention in the install instructions for REV F boards that the RAS1 pin does not work and instead should use R135.

Here is my final pics.

Thanks to everyone on this forum who helped me troubleshoot and get this running. I am beyond happy right now!!

Paul

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[coonsgm]

Woohoo! I love the feeling of a good fix.

[exxos]

@exxos perhaps a mention in the install instructions for REV F boards that the RAS1 pin does not work and instead should use R135.

Thanks for letting me know.

On my board they are wired together.

Can you post a image of the bottom of your board ?

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Maybe just using the right side pad would just be better in the install docs..