SEGA After Burner Upright - Right Speaker Dead

That is an amp also, sometimes they fail, sometimes its the larger MB3733 in the back on the heatsink

If you are comfortable with desolder / solder, you can swap them left and right and see if problem travels.

Note it is impossible to remove the MB3733 from the heatsink while caps are installed, it is easier to desolder both and remove heatsink with them attached.

You can steal an MB3733 off SEGA16b and some other boards if needed for a test also. Not easiest to find


Not vouching for the seller but this is the SIP amp you are poking at

This is the larger amp on heatsink
That's also really helpful. I'm pretty good with solder / desolder. I might actually see if it jumps.
 
My current setup on the 8 and 6 pin. What specifically should change if anything? MUTE and GND going to 4 pin? 8 pin? 🙂 Speak very slowly for the learners in the room.
looks correct to me. What I was saying is the last two on 6p header are already going to MUTE and GND in the CAB, ignore those for now. You have sound out of one channel and it sounds correct so I am confident it is not a MUTE circuit issue.
 
For the sound amp which one specifically is the PCB connection AT the PCB if you know fast, manual is…ambiguous to me
 
For the sound amp which one specifically is the PCB connection AT the PCB if you know fast, manual is…ambiguous to me

You can find a good pinout here and track it down,
 
This is not how yours will look in the cab, this is on a bench running on jamma, but these two are the audio out from PCB
 

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Okay good to know. I have to say connections were quite snug on all connectors before and after deoxit…let me go back through
 
That looks awesome.

It's definitely not the connection. Removed, cleaned, resat connection multiple times, veeeeeery snug contact, sound went away each time, came back only to the right speaker. Short of changing the ICs at IC4 and IC5 and switching to see if the problem follows, this one'll be above me and I'll have to send it in.
 
That looks awesome.

It's definitely not the connection. Removed, cleaned, resat connection multiple times, veeeeeery snug contact, sound went away each time, came back only to the right speaker. Short of changing the ICs at IC4 and IC5 and switching to see if the problem follows, this one'll be above me and I'll have to send it in.
if you are comfortable with solder / desolder, it may be easier to find than you think.
When you take out the amp board you can use DMM to check all resistors by comparing one side to the other,
check transistors for shorts and then you can swap MB3110 right with left and see if it travels, if not, you can swap MB3733 right for left and see if it travels.

I would think that you can find the problem by playing musical chairs and minimal measuring.

Or you can send it out and someone will rebuild it for you.
 
I will inspect and see if it follows and check for continuity allllllllll over. You're probably right….
 
I don't know if it's the same, but the Outrun PCB audio connector is 4 position and the grounds are the two middle ones. So you can flip that connector around to swap L and R signals out of the board. That should tell you if it's a PCB or amp board problem.
Verify the schematics before you do … or maybe someone else can confirm.
 
Okay, THAT is the bee's knees. This could save some dickery. Attaching this drawing to this thread for further exposure if someone else comes looking too. Thanks @parism.
I think the thanks should go to @DarrenF . I believe he posted this in his subwoofer upgrade in Outrun.

p
 
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I don't know if it's the same, but the Outrun PCB audio connector is 4 position and the grounds are the two middle ones. So you can flip that connector around to swap L and R signals out of the board. That should tell you if it's a PCB or amp board problem.
Verify the schematics before you do … or maybe someone else can confirm.
This should work to identify if it is the main pcb or an amplifier issue.

p
 
I don't know if it's the same, but the Outrun PCB audio connector is 4 position and the grounds are the two middle ones. So you can flip that connector around to swap L and R signals out of the board. That should tell you if it's a PCB or amp board problem.
Verify the schematics before you do … or maybe someone else can confirm.
I was thinking the same thing but think the 4 pin header has plastic wedge style so you can't flip it 180°.
 
It is wedge style. It fits. 😄

At least well enough to confirm. The wedge ends up on the backside so it's mostly out of the way.
That is extremely good to know and a good test point, I'll do that later today.
 
It is wedge style. It fits. 😄

At least well enough to confirm. The wedge ends up on the backside so it's mostly out of the way.
Yeah so flipping the 4 pin connector both ways, still sound out the same speaker.
 
Yeah so flipping the 4 pin connector both ways, still sound out the same speaker.
So you know your PCB is good. Frankly, I'd be happy about that!

You have an audio board issue it seems. Commence with the stuff that's been suggested here.
 
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