Anyone wanna help me troubleshoot my Simasimac Reloaded SE/30 board?

[Steve Rieck]

A few other things.

now grounding the scope on pin 38 of the PDS slot for a shorter ground cable. No difference really.

The NMI switch has no effect but it does go to pin 9 on the GLUE and pin 1 of RP8... can see the voltage drop at all positions when I push the switch, it has absolutely no effect and no sound on the system.

The reset switch and circuit seems to be working at all points.

5 V rail off the power supply reads 5 V but into most chips it reads around 3.9 v . I guess that's normal?

 

[vtgearhead]

At the risk of playing Captain Obvious: Are you using an x10 probe with that little scope? An x1 probe may cause too much loading on the clock signal.

 

[Steve Rieck]

At the risk of playing Captain Obvious: Are you using an x10 probe with that little scope? An x1 probe may cause too much loading on the clock signal.

that's an excellent question. I need to double check it. I am a rookie with the scope for sure but I'm careful and I'm having fun.

 

[Froggy814]

Thinking back, what isn't happening? Why are you testing all of this? What isn't working that made you start asking for help? Just curious. Not trying to be mean.

 

[Steve Rieck]

Thinking back, what isn't happening? Why are you testing all of this? What isn't working that made you start asking for help? Just curious. Not trying to be mean.

No offense taken. Just Simasimac with no sound. From my understanding could be so many things. Checking likely culprits one at a time.

 

[Froggy814]

Oh, so you're trying to get sound? Have you tried a new speaker?

 

[Steve Rieck]

Oh, so you're trying to get sound? Have you tried a new speaker?

Speaker is fine. I've used several other boards with it recently.

 

[Froggy814]

Okay, I don't know what to say...

 

[Steve Rieck]

At the risk of playing Captain Obvious: Are you using an x10 probe with that little scope? An x1 probe may cause too much loading on the clock signal.

both my scope and probe are at 1X .I set them to 10X. but I'm seeing the same waveforms at a different magnification level? I'm definitely new to using scopes.

 

[Steve Rieck]

Okay, I don't know what to say...

thanks for trying. Yeah sometimes it's the most obvious things but unfortunately not on this one.

 

[Froggy814]

Have you checked the traces? Maybe this thread could help.

No Sound Se/30 Reloaded board

I just received a serviced reloaded board. At first it didn't boot — I got the stock VRAM Simasima — but I found some of the chips weren't properly seated and tried stock ROM shifted in the socket slightly for better contact. It boots! But no sound. I am going to work with what I know / am...

68kmla.org

 

[Steve Rieck]

Have you checked the traces? Maybe this thread could help.

No Sound Se/30 Reloaded board

I just received a serviced reloaded board. At first it didn't boot — I got the stock VRAM Simasima — but I found some of the chips weren't properly seated and tried stock ROM shifted in the socket slightly for better contact. It boots! But no sound. I am going to work with what I know / am...

68kmla.org

looked at the whole board under a microscope and don't see any broken traces but it's a brand new reloaded board also… Of course I checked all the address lines and data lines and checked continuity on all pins on the glue and ASC. Gonna check the VAIS and the rest of the PLCC's as you suggested today.

 

[Froggy814]

Hope that you can find the trouble, my idea was that the phone jack was intercepting but, I don't know for certain.

 

[Steve Rieck]

Didn't Colin from This does not compute have to add a bodge wire that they added from the factory that wasn't fixed on the reloaded board, did you add it?

rewatchd that video and that's a good point but apparently that was just something that created video artifacts not a full simasimac and only for certain pal chips.

 

[Froggy814]

rewatchd that video and that's a good point but apparently that was just something that created video artifacts not a full simasimac and only for certain pal chips.

Got it, Thanks!