Can't get master status to switch out of Record mode to Remix on 8000GB **SOLVED

[TheMixfactoryNYC]

Rechecked and dissambled status switches and they are all good.

So its not the switches.

Now i am at my wits end in what to try next.

I've noticed the way the logic works, if any of the switches are not connected you can't switch statuses. It defaults to just record mode.

All of the main status switches go to a 4042 Quad gate and i've replaced that to no avail.

Any ideas?

In trying to figure how the 4042 quad clocked latch works:

The outputs Q and Q either latch or follow the data input depending on the clock level which is programmed by the polarity input. For polarity e 0; the information present at the data input is transferred to Q and Q during 0 clock level; and for polarity e 1, the transfer occurs during the 1 clock level. When a clock transition occurs( positive for polarity e 0 and negative for polarity e 1), the information present at the input during the clock transition is
retained at the outputs until an opposite clock transition occurs.

Ok so studying the schematic, the 4042 want to see 15v and 18V max.

The supply voltage is pin 16, the input voltage in pin 8 and polarity is pin 5.

Outputs are 9,3,12,15
Inputs 7,4,13,14

According to the schematic all of the switches are tapped to the polarity pin, supply voltage and input voltage of the 4042.

Now the question is why on the broadcast switch do we get (2) of the latches to open up instead of 1 and why on the remix switch do i get none?

In theory could the broadcast be sending a +/- polarity so fast that its switching between both simultaneously? Also according to the schematic some how the broadcast switch would have to be crossing both inputs which I don't see how it would be possible.

Also for the remix switch to only be able to let 9v through means that its either limited before the 4042 or after?

Before the 4042 its a 15K resistor and a small 10n cap.

We do know after i get 18v on the mix bus but only with the broadcast switch.

Trying to narrow this hard is a mind bender.lol

[sintech]

Yeah, looks like somethings corded in the Logic as you point out.

At this point I'd use an IC tester, to check all the chips.. a cheap £27 off eBay, and works great.

[radardoug]

Switches bounce and produce spurious output, when they get old they bounce more. So normally you have to have some debounce protection.
But with a latch, once its latched, thats it.
I would look at the waveform on the switch with a scope and see how bouncy it is. If its a lot, change the switch.
I'm sure SSL would have allowed for a degree of switch bounce. I haven't looked at the exact circuit so I could be wrong.

[TheMixfactoryNYC]

Yeah, looks like somethings corded in the Logic as you point out.

At this point I'd use an IC tester, to check all the chips.. a cheap £27 off eBay, and works great.

I switched out the T1 4042 and a couple of the ICs from an older 82E21 card that I purchased and the same problems happen. I also purchased a whole bunch of extra 4011 and 4013s in case they are needed.

[TheMixfactoryNYC]

Switches bounce and produce spurious output, when they get old they bounce more. So normally you have to have some debounce protection.
But with a latch, once its latched, thats it.
I would look at the waveform on the switch with a scope and see how bouncy it is. If its a lot, change the switch.
I'm sure SSL would have allowed for a degree of switch bounce. I haven't looked at the exact circuit so I could be wrong.

I noticed that the all of the status switches have a cap and a diode soldered to them and from checking them they all seem good.

I will try to grab a switch somewhere else on the console to test.

[TheMixfactoryNYC]

Does anyone know off hand what is the EAO equivalent for a SP momentary 33DMD118 switch ?

[sintech]

Have got a tonne of momentary EOA switches in Grey if you need some.

[TheMixfactoryNYC]

Yeah i can use some.

Sent you a P.M.

[TheMixfactoryNYC]

Ok here is the update.

I switched out the ReMix switch and now i get 11v across the switch.

Great.

Bad news i still can't get it to turn on the Mix status bus.

It still at -18v for the lamp and 0V for the bus.

I now am not sure what else to try. If i have to switch out the mix bus and mix lamp transistors at this point i will do it. I've changed out all of the 4011, 4013 and the T1 4042 logic chips. All of the diodes and resistors between the mix switch and  lamp/bus all check out fine. According to the schematic all that is left are the transistors and some small caps.

Has anyone ever encountered this before? Any solutions or ideas of what else to try?

[TheMixfactoryNYC]

Another update, switched out all status momentary switches for new ones.

I still only get 10V for the mix status buss when i remix is selected.

When i select the Broadcast status i get 19V on the mix status bus.

Again I am not sure what else to try.

I do notice that when i switch to the remix status, the routing lights want to turn on but they don't.  Same as the Broadcast mode. they blink momentarily and then nothing.

In the past when you select Remix status the routing lights would be selected for the small faders automatically.

Is this a clue for anyone what the problem could be?

At this point I am baffled and am backed up on work because of this problem.

[TheMixfactoryNYC]

Just tried 2 different 4042 IC chips.

One i pulled out of an old CF82E21 card and it would keep the Remix switch selected even when i selected Record or Broadcast. Also when I selected Broadcast it would select the remix switch. Another i noticed is the Master input flip switch was easier to select. When I switched to the current one I had before that phenomena went away, but i still got the +19v mix buss when I selected the Broadcast switch.

So then its possible that the 4042 is the problem, but what are the chances that 2 different ICs behave in a similar manner?

I since ordered some brand new 4042 ICs and when i get them will try it  and see if maybe it will finally fix the problem.

[xmax]

You might also consider disconnecting S3E ribbon to first the left and then the right of center
section feeding the buckets, I did not have time to read the whole thread so I'm not sure
this is relevant, but perhaps a bad logic board in a module is locking things up. Also I have
had fets short on the status card that does master flip, (21?) It happens when people try to
hot swap a module.
 

[TheMixfactoryNYC]

You might also consider disconnecting S3E ribbon to first the left and then the right of center
section feeding the buckets, I did not have time to read the whole thread so I'm not sure
this is relevant, but perhaps a bad logic board in a module is locking things up. Also I have
had fets short on the status card that does master flip, (21?) It happens when people try to
hot swap a module.

I've tried to get the remix switch to work without the buckets on and switch is still not changing status.

The card that does the master flip is the piggy back card  PCB 82E21 Sub card or 82e198-01 ISSAB.

I switched out the 4013 just in case but all of the transistors, diodes and resistors check out on the piggy back card.

[TheMixfactoryNYC]

Just tried 2 different 4042 IC chips.

Ok an update.

Tried a brand new 4042 IC Latch and still get the same problem.

Now this time I tried the 82E21 card without the piggy back card and something different happened. Now in Remix(Mix) mode I get the routing to the small faders, but I still can't get the tape returns to feed the large faders. I still can't get the mix bus to give me +18v.

And still when I select broadcast status, I get the +19v on the mix bus .

Also there is no difference when i switch between Record and Mix.

Does anyone have any ideas why this could be and what else to try?  Also does anyone know in MIX mode should the VCA to monitor buss be giving +18V without selecting the switch? Because in mix mode I am not getting the +18v in the VCA to monitor buss.

How does the board know to default to mix mode when it powers up? Also I am not running the computer as the 8000GB don't come with the cards so could that be an issue? I have all of the terminators in the VCA slots under the board.

I would really appreciate any help. I've changed out every IC on the 82E21 card. All the resisitors and Diodes check out fine as well as the Transistors.

[TheMixfactoryNYC]

Just tried 2 different 4042 IC chips.

Ok an update.

Tried a brand new 4042 IC Latch and still get the same problem.

Now this time I tried the 82E21 card without the piggy back card and something different happened. Now in Remix(Mix) mode I get the routing to the small faders, but I still can't get the tape returns to feed the large faders. I still can't get the mix bus to give me +18v.

And still when I select broadcast status, I get the +19v on the mix bus .

Also there is no difference when i switch between Record and Mix.

Does anyone have any ideas why this could be and what else to try?  Also does anyone know in MIX mode should the VCA to monitor buss be giving +18V without selecting the switch? Because in mix mode I am not getting the +18v in the VCA to monitor buss.

How does the board know to default to mix mode when it powers up? Also I am not running the computer as the 8000GB don't come with the cards so could that be an issue? I have all of the terminators in the VCA slots under the board.

I would really appreciate any help. I've changed out every IC on the 82E21 card. All the resisitors and Diodes check out fine as well as the Transistors.

Ok, i've learned a couple of things today.

First of all I pulled out all the cards to the 651 and I checked the actual wires from the 651 to the switches and I learned something new. The pins on the 651 do not correspond to what i actually thought were the pinouts on the 82E21 card. Actually they are different and reading the schematic I think i understand.

The pins for the mix switch do not correspond to the mix lamp, mix switch and mix bus, its actually to the Replay switch,  Replay lamp and splits off to the VCA to monitor bus from the output of T4. Aahhhh!

Now we are getting somewhere. Same goes for the broadcast switches and record switches.

In the schematic the Record switch is really the mix switch(schematic) and the Broadcast switch is the record switch(schematic).

Ok on the schematic once the signal leaves the T4 IC its splits to the Replay Lamp and then to a 4.7Kohm resistor then to the VCA to monitor bus. So the problem has to be somewhere in that signal flow.

I measured the Replay Lamp and its giving me +13V and I am pretty sure from measuring it before the VCA to monitor bus is not giving out 18V.

This goes all the way back to the original problem that caused all this, the Transistor for the VCA to monitor bus completed melted and pulled some of the traces off the 82E21 card. I replaced that transistor and redid the traces with wire. So now for some reason i am still not getting the VCA to monitor to output 18v or in Remix mode to get the tape returns to feed the large fader.

I guess what i can do next is replace the transistor to the Replay lamp and recheck the Transistor for the VCA to monitor bus, but I've checked that out a million times.