Fixing a DE-10 nano with SDRAM issues?
Posted: Wed Apr 06, 2022 7:11 am
Hi all. I have a DE-10 nano that "partly" works with MiSTer. I was wondering if anyone might have any thoughts/advice on how I might possibly troubleshoot/fix it. It may just be a lost cause though...
The issue is that when I plug in an SDRAM module (I've tried a few) some of the cores that should work, don't. It's as if only some of the SDRAM can be used but not all of it. I have another fully working de-10 nano by the way, so I know that the problem is with this DE10, not the SDRAM modules I have. I have inspected the pcb, pins, etc. and don't see anything that looks unusual. I can't figure out where to check for continuity tests though, I don't see any traces to check...?
Here are some other bits of info that might be relevant:
- without any SDRAM it runs just as it should, running cores that are expected to work just fine
- with 128 mb SDRAM the icon on the OSD is correct, with 32mb SDRAM the icon shows as no SDRAM is installed
- when I plug in 128mb SDRAM in I can use *some* cores that need SDRAM, e.g. computers C64/Amiga/Amstrad and arcades 1942/Commando work fine but Double Dragon/Dinos & Cadillacs and NEO GEO don't
Doesn't seem much works at all with only 32mb SDRAM (other than those that don't need SDRAM anyway).
- SDRAM Test never reports a success, even with known good SDRAM (red numbers just go crazy every few secs). It reports 128mb correctly (i.e. "3") but doesn't seem to see a 32mb stick at all (reports as "0")
- SDRAM was never put in the wrong way, wrong side, etc. it's been like this since I bought it (I was sent a working replacement)
My guess is that some of the SDRAM can be accessed fine so it just depends on which "section" of the SDRAM each core attempts to use?
Anyway, any thoughts are much appreciated. It would be great if I could get this fully working again. It's still useful for some cores I guess, but it's just not really a MiSTer at the moment
The issue is that when I plug in an SDRAM module (I've tried a few) some of the cores that should work, don't. It's as if only some of the SDRAM can be used but not all of it. I have another fully working de-10 nano by the way, so I know that the problem is with this DE10, not the SDRAM modules I have. I have inspected the pcb, pins, etc. and don't see anything that looks unusual. I can't figure out where to check for continuity tests though, I don't see any traces to check...?
Here are some other bits of info that might be relevant:
- without any SDRAM it runs just as it should, running cores that are expected to work just fine
- with 128 mb SDRAM the icon on the OSD is correct, with 32mb SDRAM the icon shows as no SDRAM is installed
- when I plug in 128mb SDRAM in I can use *some* cores that need SDRAM, e.g. computers C64/Amiga/Amstrad and arcades 1942/Commando work fine but Double Dragon/Dinos & Cadillacs and NEO GEO don't
Doesn't seem much works at all with only 32mb SDRAM (other than those that don't need SDRAM anyway).- SDRAM Test never reports a success, even with known good SDRAM (red numbers just go crazy every few secs). It reports 128mb correctly (i.e. "3") but doesn't seem to see a 32mb stick at all (reports as "0")
- SDRAM was never put in the wrong way, wrong side, etc. it's been like this since I bought it (I was sent a working replacement)
My guess is that some of the SDRAM can be accessed fine so it just depends on which "section" of the SDRAM each core attempts to use?
Anyway, any thoughts are much appreciated. It would be great if I could get this fully working again. It's still useful for some cores I guess, but it's just not really a MiSTer at the moment