The Fun Never Ends With My 388 Misadventures

  • Thread starter Thread starter Mark7
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Mark7 said:
No, on the boards. There's a P103 (it's actually just 103) on the A board (that's the 9 pin one) and a 103 on the B board (the 8 pin one)
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Oh yes. Right. There may be the same labels between different boards, and that’s why I am specific we are talking about Pxxx on X PCB. Make sense?
 
sweetbeats said:
Okay. We’re still on the BUSS A PCB.

P104 is white 8-pin connector. It should have a white plug that connects to it, and at the other end of that is a red 8-pin plug, and that connects to red connector P121 on the MONITOR PCB.
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There's only one cable that fits that description. Done.
 
P108: this is a white 9-pin connector. It should have a white plug connected to it that goes to another 9-pin white plug that connects to white connector P101 on the meter PCB up in the meter bridge.
 
Wait. You skipped 105 - 107.

Okay, just realised why (wrong board). There's only one 9 hole white connector wired to the back of the machine so I plugged that on to 108. The other is wired to the front. Also, I can't see the meter bridge PCB
 
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I’m looking at the schematic and there is no P105, P106 and P107. Do you see them on the physical PCB?
 
I have to step away for awhile, I’ll check back in as soon as I can.
 
I see 105 on the B board, also 106. I thought we were doing them in numerical order but it seems we're doing one board at a time
 
I also have to step away for a while. Like 8 hours.

G'night! (just post the next one whilst I'm bed and I'll deal with it when I wake up).
 
Wait. You skipped 105 - 107.
Mark7 said:
Okay, just realised why (wrong board). There's only one 9 hole white connector wired to the back of the machine so I plugged that on to 108. The other is wired to the front. Also, I can't see the meter bridge PCB
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Right I wasn’t thinking you’d be able to see the PCB, just telling you where it goes in case you could glean some indication the wires were headed that way vs somewhere else. The meter PCB is up in the meter bridge in front of some of the plug-in cards in the cardbay. Your logic sounds good though (only one connector if that type with wires going to the back).
 
Okay, still BUSS A PCB…

P109: this is a white 4-pin connector, and connected to it should be a white 4-pin plug. The wrinkle here is that there are, like, 4 or 5 white 4-pin plugs that connect to the BUSS A, BUSS B and MONITOR PCBs. Which one is the right one? The one that connects to the BUSS A PCB goes to the back of the machine…the other end is directly soldered to the jack PCB with the EFFECT RETURN jacks. The added wrinkle here is I think there are two white 4-pin plugs that travel back to the back of the unit. I know you probably can’t physically trace out which one goes to the EFFECT RETURN jacks, but there might be a couple other things you can do to verify which one is the right one. I think the correct plug has two colored wires going to the 4 pins, the colored wires connecting to pins 1 & 3 of the white 4-pin plug, with black wires branching off of the two colored wires going to pins 2 & 4. I think this is the only one like this. The other way to verify is to plug a TS to TS 1/4” cable into the EFFECT 1 RETURN jack and take your multimeter and measure for continuity between the tip of the cable to pin 1 of the 4-pin connector. There should be only one that has continuity like this, and that’s the one that goes to P109 of the BUSS A PCB.
 
I have three four pin connectors with red and brown... master wires. Christ what idiot thought it'd be good idea to put wires in wires? One has alternating white and black sub wires (again, I don't know the terminology) whilst the other two have white wires on the outside holes and black on the inner holes. There's a fourth with yellow and orange master wires and the same white out, black in arrangement of sub wires as red and brown 2 and 3. I chose red and brown 1.

Can we call any wire that encompasses other wires "master wires" from now on? Or is there an actual word for them?

Also can we move on to 110?
 
Mark7 said:
I have three four pin connectors with red and brown... master wires. Christ what idiot thought it'd be good idea to put wires in wires? One has alternating white and black sub wires (again, I don't know the terminology) whilst the other two have white wires on the outside holes and black on the inner holes. There's a fourth with yellow and orange master wires and the same white out, black in arrangement of sub wires as red and brown 2 and 3. I chose red and brown 1.

Can we call any wire that encompasses other wires "master wires" from now on? Or is there an actual word for them?

Also can we move on to 110?
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We’ll move on to BUSS A PCB P110 as soon as we verify the P109 connection. You risk stuff not working right or possible damage if the wrong thing is connected.

What you are calling “master wires” are just shielded cable. You don’t like them because you think they are dumb, but shielded cabling is what keeps your audio path from inducing RF and UHF noise from the environment, or other unwanted noise from inside the unit. There is a center conductor wire with insulation around it, and then a braided wire jacket around that with an overall outer layer of insulation. The “white wire” is the inner insulation layer around the center conductor. That’s carrying signal. The “black wire” is the braided shield twisted into wire with heat shrink over it. That’s the shield that is connected to signal ground to shunt the noise it induces. So…become friends with it. Let’s call these wires “shielded” wires.

So before we move on, just to verify, you have a plug connected to P109 that is like this?

Pin 1 = white center conductor from brown wire
Pin 2 = black shield from brown wire
Pin 3 = white center conductor from red wire
Pin 4 = black shield from red wire

Do I have that right? If so, I’m reasonably certain that’s the correct plug that mates to P109.

Verify and we’ll move forward.
 
Okay. So last connector on the BUSS A PCB, P110, should be mates to a white 3-pin plug that goes to a white 3-pin plug that mates to P106 on the BUSS B PCB.
 
How many wires does it have according to the manual? Mine only has a single brown wire.
 
It doesn’t matter how many wires…how many conductors? There should be three. Pin 2 is probably black because it’s a shield, and if you only have one cable it’s probably a two-conductor cable with braided shield. So tell me what you see populating the plug housing…three conductors?

Pin 1 some color wire
Pin 2 black wire
Pin 3 some other color wire

?

Something like that?
 
That’s the one.

Okay. So now that we have the BUSS A PCB properly connected, let’s move on to the BUSS B PCB.

P101 and P102 connect to the long buss PCB that goes across all the mixer PCBs.

P103 should already have a big red plug mated to it from the bunch of wires soldered to the BUSS A PCB.

Are we good so far? If so, let’s move on to P104. This one I believe mates to what is the only white 4-pin plug with the yellow and orange shielded cables, pins 1 & 4 carrying the signal from the yellow and orange cables respectively, and pins 2 & 3 populated with the black insulated shield wires from those shielded cables. This set of wires goes to the back of the unit to the jack PCB with the STEREO BUSS IN jacks FWIW.
 
Erm, Now I'm confused. The m.buss PCB connects to all the cards in the mixer section. There's no P101 or 102 connections on it. I'm sure there are photos of it onlinr you can look at which will verify this. The only connectors labelled P101 and P102 are on the individual input channel pcbs, and there are only certain plugs that attach to them (8 of each). There's no way to connect anything to the m buss
 
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