AES 3-6 w/ No Video or Audio

daskrabs

Ace Ghost Pilot
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I have an AES 3-6 that boots to black screen with or without game. Using a 10v 1a negative tip PSU as specified. It's getting power. No obviously damaged traces or components. Any thoughts on where to start? Sometimes, without a game, it flickers slightly blue, then goes completely black.
 

Xian Xi

JammaNationX,
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If no sound or video and screen is black, it means the master clock is dead. Check the 24.16mhz crystal near the mem card reader.
 

daskrabs

Ace Ghost Pilot
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How do I test the crystal? I have a meter, but no oscope.
 

aha2940

AH, A, COLUMBIAN!,
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How do I test the crystal? I have a meter, but no oscope.

The crystal is a small, not so expensive part, why not replace it to be sure? it is way less expensive than a oscilloscope, anyway.
 

daskrabs

Ace Ghost Pilot
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I swapped a crystal from a working MVS board, no change. Any other ideas?
 

aha2940

AH, A, COLUMBIAN!,
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You said no obviously broken traces, but have you actually checked them using a voltmeter or watching them with a mignifying glass? some traces are very thin and can look OK but be actually broken. At least now you know the crystal is OK. Did the working MVS board keep working after swapping crystals?
 

daskrabs

Ace Ghost Pilot
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Yes, the MVS board still works. I still have to run connectivity on the traces. I swapped out the BIOS with a Unibios. No debug information, sadly, but the board now has the click of death. It's the fast click on a black screen. True for either BIOS. I'm leaning towards dead 68k. It stays totally cool to the touch when turned on, whereas the YM2610 and Z80 both warm up.
 

Xian Xi

JammaNationX,
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Are you testing via RGB or composite or something else? And your TV can display 240p?
 

daskrabs

Ace Ghost Pilot
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Testing composite on a PVM. I haven't tried RGB, but could. Will that make a difference?
 

BIG BEAR

SHOCKbox Developer,
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You may need to try another PWR supply OR it could be a bad AC input socket.
I have a unit now with the same problem that needs the AC input socket replaced.I can fiddle with the socket while it's plugged up and get a game to boot or blue screen.
BB
 
Last edited:

daskrabs

Ace Ghost Pilot
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I traced everything from BIOS to CPU. Found 1 bad trace between LSPC2 and NEO D0. Repaired, but still no joy. I'm using this as a guide. Not sure why BIOS pin 20 says it should be connected to NEO E0 pin 59. 59 doesn't look like it's connected to anything. I ordered a new 68K, still leaning towards that. Apparently other people have had their 3-6's 68k die.

Power supply is good. Getting 5v to the right spots. Composite and RGB yield the same thing.
 

BIG BEAR

SHOCKbox Developer,
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What is it with the 3-6? I have one now that needed atrace repair from the ls244 to the 53100.Then I had to repair a couple of traces to the p1 port,now the UP direction stopped working. Make sure you pick up a few sockets for your 2610 and your 6800.
I just purchased two sets and made the mistake of getting the WIDE version (mesmerorized by the gold pins and missed it in the description....)
BB
 
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