Questions About The Numark MixDeck Onboard DC Port

[CapLeaker]

A block diagram lets you see in highly visual blocks without resistors, caps only showing the main components on how this thing is working. It would have very simply shown on one page how the data flows to the LCD displays,

You got nothing showing on both displays. So whatever it is could be a single thing affecting both displays. So follow the data lines. If the main chip isn’t doing anything for whatever reason nothing will be on the displays for example. Same thing if a chip needs a crystal to work. Crystal dead, a dead buck converter, etc… chip not working either. There is tons to check and cover.

[TurcoLoco]

Yeah, you are right, no such page. Just wiring diagrams, assembly diagram and negative PCB shots (whatever they are for).
I will ask to see if they have it but I am guess if they did, they'd have sent it already.
Shame such a detailed service manual too.

What I meant with a single thing is, it is not likely to be a capacitor or resistor located on the display board as both are having the same exact issue.
How could have a data line crap out, is a mystery to me. This thing is too exotic and the only reason I took on the job was because it seemed like a straightforward socket replacement.
He just paid for the parts as I am not even charging the guy as I told him this is not something I normally do.

I am aware there is a lot to cover but I still would like to do some troubleshooting a bit, if I can, if nothing else, to gain experience.
If you can throw anything my way to check, I'd appreciate it.
Either way, I am grateful for the help I got this far!

Cheers,
Matt

[CapLeaker]

You can check all voltages, buck converters, crystals, and some data lines from SPI chip or IC2 and others. This SM is very hard to look at on my iPad. Too much scrolling and zooming in out. This isn’t nearly a detailed SM. There are others that are much more detailed than this.

Look at the PIC chips. Check basic things like correct voltages, oscillator, SPI data line. Then both sides need to be able to talk to each other and I think that this may be done via this IC2 data bus, but not sure about that. The SPI flash has firmware on it. Could be corrupted or dead.

You could look for a factory service or troubleshooting port like a TTL then hook up a USB to TLL and run a terminal and see what it does.

[TurcoLoco]

You can check all voltages, buck converters, crystals, and some data lines from SPI chip or IC2 and others. This SM is very hard to look at on my iPad. Too much scrolling and zooming in out. This isn’t nearly a detailed SM. There are others that are much more detailed than this.

Look at the PIC chips. Check basic things like correct voltages, oscillator, SPI data line. Then both sides need to be able to talk to each other and I think that this may be done via this IC2 data bus, but not sure about that. The SPI flash has firmware on it. Could be corrupted or dead.

You could look for a factory service or troubleshooting port like a TTL then hook up a USB to TLL and run a terminal and see what it does.

Hi Capleaker,

Thank you. I will check all the voltages I can think of in hopes of finding something off.
I did (like the idiot I am) splash some solvent to my face a few days ago, luckily I was wearing glasses but my face is pretty awful right now.
I think the chemical burn also got infected so one of my eyes is also a bit swollen. It is getting better but slowly.
I will work on this when I feel a bit more up to it.

What sucks is having both parts still connected to check voltages due to very limited opening, it will be a pain.
Oh well, I will post back when I have done some checking.

Thank you again.

[TurcoLoco]

Hi Capleaker,

I got an email from their tech support today. One of the techs was able to get a copy of the block diagrams from an engineer and emailed it to me!
It didn't seem that comprehensive but perhaps this is due to my lack of knowledge/skills.
Let me know what you think!
It has a few pages so it shouldn't be too bad even on an iPad.

TIA.

PS. After 58 posts and 2+ months, I am still getting the image (human) verification!
Is there a mod I can talk to about this annoyance? What is the dang threshold?

[CapLeaker]

This block diagram is somewhat helpful, but said nothing much on what we need. We know now how the boards are connected and talking to each other. But as far as the display goes there is nothing.

Under a Block Diagram I understand this: see attachment.
This block diagram is for something else, but you get the idea once you see it.

[TurcoLoco]

Yeah, even though I don't know anything even when I saw their block diagram, I thought "WTH is this?"
It looked too simple and also limited but hoped maybe it'd make sense to you!
So, this won't help us know what to troubleshoot, huh?

[CapLeaker]

That block diagram isn’t much good here, as it tells you how are things connected, but it still leaves the display out. So… in a situation like this you have to start somewhere. And the first thing to do is to check that power is getting to everything where it needs to be. After that it’s probing around with the oscilloscope. Start with the PIC IC and see what you see. Look at the SPI data line, voltage, clock, etc. My guess is that something is dead. That schematic is a pain to look at on my little iPad as I constantly need to zoom in and out and move the page around.

[CapLeaker]

I made some green highlights around the chip to poke around with the oscilloscope.

[TurcoLoco]

I made some green highlights around the chip to poke around with the oscilloscope.

Thank you so much!
So, should I check this and other chips for the claimed voltages to make sure it matches or just use the scope?
Having never used the oscilloscope, what will I do exactly (what am I looking for)?
Sorry, for being such a pain!

[CapLeaker]

All we are looking for are 3 things. Number 1 is obvious being DC voltages. Number 2 is data flow and 3 is oscillators oscillating.
Settings on the oscilloscope are a factor, otherwise you don’t see anything. I suggest you watch some tutorials on how to use an oscilloscope and get familiar with its settings and how to reset it just in case you bugger the settings up.

[TurcoLoco]

All we are looking for are 3 things. Number 1 is obvious being DC voltages. Number 2 is data flow and 3 is oscillators oscillating.
Settings on the oscilloscope are a factor, otherwise you don’t see anything. I suggest you watch some tutorials on how to use an oscilloscope and get familiar with its settings and how to reset it just in case you bugger the settings up.

I am feeling much better so I will start with the Voltages.
Not sure how to do the data flow part but for oscilloscope, I have watched a few video but wasn't sure if it had MM like different settings for different purposes.
I will do more training on it and then give it a shot.
Thank you.

[TurcoLoco]

OK, the diagram and pins you want me to check was for the 2 big square chips on each end of the U shaped main board but there is NO way I am going to be able to do while the top piece is still attached.
I cannot even see the entire chip yet along be able to access it. I am going to take it apart to check all that.

While I was checking the voltages around the DC connector, I noticed one of the nearby capacitors is showing -12V when I touch the top of it with the MM. I checked and all the others were showing 4+ M Ohms. The bigger capacitor is the one adjacent to the one I removed, cleared (checked OK) and re soldered back onto the board (see the attached photo with the cap reading -12V).

If it is a def. red flag then I didn't hallucinate the smoke but just went after the wrong cap. If that is definitely something I need to correct, still not sure if it would cause the issue I am having or not but I still have to correct that nevertheless.
Thanks.

[CapLeaker]

Sometimes caps can have a negative reading, because they sit on a negative voltage rai. So GND or 0V would be positive and -12V negative.

[TurcoLoco]

Yes, this cap is sitting on the -12V rail so, you are saying it is normal?
Curious, why the others, +12V and +5V both showing 4 M Ohm resistance then?

Seems like I will have to continue with checking the chips on the board tomorrow.
Thanks for the clarification.

One question, the chip in your attachment has 25 pins, which chip is this exactly?
The big one I was looking at has like 40-50 pins on each side, the others have less than 25.
Is it located somewhere else and not the U shaped main board?

[CapLeaker]

When in doubt take it out and check the capacitor out of circuit.
All I’ll see is that what’s in the service manual. Maybe this chip is somewhere else. But I doubt they used a different chip with less pins, as the SM would need a major revision.

[TurcoLoco]

When in doubt take it out and check the capacitor out of circuit.

I was thinking the same thing!

All I’ll see is that what’s in the service manual. Maybe this chip is somewhere else. But I doubt they used a different chip with less pins, as the SM would need a major revision.

I guess I am gonna be playing "Where is Waldo?" with this mystery 25-pin chip!
lol

[CapLeaker]

It’s a 100 pin. 25 x 4

[TurcoLoco]

I know, sir. I was referring to each side.
I didn't see a matching chip on the mainboard which puzzled me a bit but now that the board is out, I will investigate further.
I don't think I will need to connect it to the other parts just to check voltage, or, perhaps, even the data.
I am still not 100% what I will be looking for with the scope but I will check around as best as I can.
Thank you again.

[CapLeaker]

Data should appear as square or rectangular blocks.