Macross PCB No Audio & CMOS Error

[Falken Hawke]

Working going into storage but when pulled found corrupt video in the form of two stripes from top to bottom (w/monitor oriented vertically) about 1" wide and no audio. Test pattern distinctly show missing areas corresponding to mentioned stripes.

Any assistance with this is greatly appriciated.

[Falken Hawke]

Finally able to start looking around and found a couple of open capacitors.

Of course, being a weekend, the only source of passives is closed so dead in the water 'til Monday...

I guess I'll start collecting datasheets for now. Can't reallly continue with open circuits.

[bobbyb13]

Wow, that IS really funky.

Wish I could be of use but I am NOT that smart yet.
Somebody here should know what is causing it though.

And that is a test pattern generated by the board?!
Never seen anything like it.

[Falken Hawke]

Hey Bobby!
This board has a test mode which has two screen test patterns, similar to the Neo Geo MVS 

Figured out RAM Error address:
09 C0 10 0

I just cycled the Object Output Tests and compared their ID's with the error.

Unfortunately, also found no objects display in test which is interesting because play is largely unaffected.

[Falken Hawke]

Anyone familiar with Yamaha YM2203C and/or YM3014B?

[bobbyb13]

I saw that Delusional Jay had mentioned yotsuya has one of these!
I imagine if he catches wind of this thread he will chime in with wisdom of some sort.

Wish I could be more than moral support at this point.

At least I can keep bumping your thread until somebody smart sees it!

[Mike A]

Without a schematic, which probably is not generally available, this will be a real challenge.

The no audio problem can be partially diagnosed. Find the amp. Wire a small amp and speaker to the inputs in front of the on board amp and see if you get sound. If you do, then the amp is bad and needs to be replaced.

If there is no audio with this method then the problem lies further back in the circuit and...no schematic = big problem.

There are people that can probably figure this out without the schematic, but I am not that crafty even with a schematic.

I don't work on newer boards like this one so maybe this method won't work. I just figured I would throw it out there.



Have you put both sides of the PCB under a magnifier? Look for broken traces and bad solder joints?

[nitrogen_widget]

i looked and looked hard and this was the best i could come up with for macross as far as a manual goes.
which really isn't much.

http://wwyss.ch/Arcades_Manuals/Manuals/Arcades/MACROSS_MANUAL.PDF
http://wwyss.ch/Arcades_Manuals/Manuals/Arcades/MACROSS.pdf

also, SO MANY arcade manuals and schematics on that site!

other games i found info on the CMOS errors.
the battery can go bad and corrupt the NVRAM.
they suggest new battery and going into the menu and doing a full factory restore.

i don't know if this helps.
if it worked going into storage the battery could of very well gone dead and corrupted the stored settings.

[PL1]

SO MANY arcade manuals and schematics on that site!

Bookmarked.   


Scott

[yotsuya]

The audio on my board went out a year or so ago, it was just the audio amp. All you need to do is swap it out.


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[yotsuya]

Oh, one other thing, and it’s minor, but check on it- make sure your power supply puts out -5v. Some power supplies don’t but some JAMMA boards need them for audio. I scored a Macross II board for cheap on eBay listed as audio not working this way.


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[Mike A]

That is a good point.

I had a Super High Impact board that was missing a bunch of sounds, but not all of them.

My candy cab was not wired for -5V.

Hooked the -5V line up and I had full sound.

[bobbyb13]

The symmetrical blank bars are one of the weirdest graphic failures I've seen.

What could cause something like that anyway?

[Falken Hawke]

Thanks for all the help!

I'll be able to check -5 when I get home tonight.  The audio amp I traced back to find no input signals from the Yamaha YM2203C so not sure it's the amp.  Never confirmed where -5 went so if that's the issue, I'd be happy.

Still haven't looked at the display issue except for isolating it to the A01 ROM portion of the board.  Onve I have audio again, I'll look further.  Kimda want audio 1st since it is playable as it is.

Thanks again everyone!

[Falken Hawke]

WOOT!!

So, not fixed but found HUGE help.  Time Soldiers uses a YM2203C as well!  Already confirmed stuck outputs so now will need to verify inputs and I/O paths to try and narrow down the issue.

Unfortunatey (or fortunately) I have a good -5V to the board.  As I've determined the YM2203C isn't sending output to the amp, I'll start tracing from there.

So I guess, Time Soldiers help maybe?  🤣

---EDIT---

...or not...  Looking at chip upside down🙄

Either way, known good comparison 😃

...and looking more like bad amp...

[Falken Hawke]

LOL, I'm going to step away from this for a bit.  Obviously I'm tired and stuff...

I figured I have an audio amp board I just put together for another project so I could hook it up in place of the amp chip.

After doing all that, still no audio.  I was bummed as that would've been a simple fix but then I looked closely at my audio board...

Where are the heat sinks?  Wait, where are the amps?!  Frack, I didn't install them yet! 🤣

[Falken Hawke]

So finally able to take a look at things again and decided to take a look at the LA4460 data sheet again and noticed there were pin voltages stated...  talk about overlooking things...


Anyway, whole lotta wrong out of it.  Verfied readings with Time Soldiers just to be extra certain.


Now I have someplace to begin with on the audio side.  Hopefully there isn't anything else further down the line.

[Falken Hawke]

Well, blind replaced the audio amp and no luck. Still didn't check the pin values 'cause disappointed...

Maybe start again tomorrow...

[yotsuya]

Bummer, man. That’s all I had to do for mine, but I didn’t have any graphical issues.

Here’s hoping you can get it tracked down!


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[Falken Hawke]

Found a little more help on the audio side in the form of the schematic for "Ghosts & Goblins" which uses the YM2203 & YM3014 chips for audio.  The op-amp and amp chips are different but functions are similar.

Driving on...

[Falken Hawke]

If anyone has an oscilloscope and working board, I was wondering if I could get a few waveforms verified?

If I could get the waveform from pin 38 on U33 (YM2203C), that would be appreciated

Also, U59 (74LS74), pins 3 & 11.

200mV @ 500uS x10

Thanks!