RAM failure

[Maskenlos]

Hi all,

One of my QLs fail to boot and a Minerva RAM failure information appears just before completing the RAM test:

[img]Ram_test.jpg[/img

This leads to the information that all RAM chips 1-8 are bad. To me this is a little bit unlikely but of course still possible.
As the complete lower bank seems to be not working I am also suspecting IC 19 - 20 to have an issue.
Is there any way to further trace down whether the multiplexer ICs (19/20) or really the RAM ICs have an issue?

Thanks,

Stephan

[Derek_Stewart]

Hi,

Try running the Ramfail_bas programme from the Minerva support disk and it will tell you which ram chip is faulty.

[Maskenlos]

Hi Derek,

thanks for your answer. This is basically what I did but using the tool here:

https://www.nightfallcrew.com/minervaram/index.php

It tells me that all Ram chips from 1 to 8 are faulty. Which is somehow unlikely to me and let me think to check for other possible causes first before changing all 8 ram chips.

Stephan

[Derek_Stewart]

Hi Stephan,

I forgot about the NightfallCrew web page.

If all the ram are faulty, maybe as you suggested it is the decoder chips that are causing problems.

I used to test each gate in chip with a logic probe, time consuming, but finding the fault without removal of the logic chip and testing the in a chip tester.

[Maskenlos]

Problem solved. Thanks to everybody who contributed

Stephan

[Derek_Stewart]

Hi,

Do you want to share the solution to your problem.