dreamer

MB6582 powers on when Jack is connected

24 posts in this topic

So here is the strange problem i have.

When i connect a Jack connector or MIDI connector to my MB6582 the synth powers on and can not be switched off with the powerbutton untill these cables are disconnected again.

This only counts for connectors that are connected to other modules that have power on it. So for instance my external USB soundcard will power the synth on. But a headphone that is connected directly to the MB6582 will not power the synth on.

 

IMG_20160412_193256.jpg

IMG_20160412_193305.jpg

IMG_20160412_193459.jpg

Edited by dreamer
added photos

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What PSU are you using? The C64 one? Does the board pass the voltage tests like this?

Do you mean it powers up with no PSU connected? That's pretty strange if so; perhaps you have a wiring problem in your house? You could have mains voltage where it shouldn't be. Check again through Wilba's layout that you've made the correct mods and upload an annotated image here to confirm.

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The way i'm powering this is by running it off a single DC powersupply. All the details and pictures how i have wired are discussed in this topic:

Most of the latest replies to this are me asking attitude how i must proceed with powering the MB6582 this way.

 

Edited by dreamer

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Hi,

Just looked at your pictures.

Maybe there is a short where the yellow wire crosses the hole?

Perhaps test the solderjoint and the hole with the multimeter.

X

 

 

misschien.png

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I measured that suspicous wire and did not measure any problems. Still decided to remove that wire completly because i will not be using it for this build i only need that bridge when i wanted to use 6581 sid chips but decided to not use these. After i removed the wire and connected everything again the problem is still not solved :fear: the mb6582 still does the same thing.

Any more suggestions what to try?

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For me you still haven't explained the problem well. Because this is a modified build, you need to clearly document all changes here. Like drawing all bridges/cuts/substitutions/omissions on the layout file -- it doesn't have to be a work of art, you could use Windows Snipping Tool or a screenshot with a basic drawing program. Please don't expect others to go through all of the disparate threads and collate the info for you. 

I'm happy to try troubleshooting if you give some more info. :happy:

And I repeat my "stupid" question above; does the MB-6582 power up only if the DC adaptor is plugged in and switched on? What is the voltage? What kind of PSU is it?

How is the other equipment powered? 

It's important to check your wiring, because there are some complicated powering schemes possible in the MB-6582. Some involve adding two rails together which only works in certain circumstances, and also means "ground" is not always 0V! I assume you're only want to use 9VDC for the SIDs, which means you should come in with ~12VDC and regulate down to 9VDC. 

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i tried to explain how everything is connected by pointing you towards the other topic. But maybe easier to repost it here. 

Power-Section-Guide1.jpg.941adcfb395ce05

So above picture show how the bridges are running with a component list on the right side. The PSU i'm using is a 15V / 2A switching power supply. I choose 15V because at first i also wanted to be able to use 12V for the 6581s the bridge previous mensioned is now removed so 12V is not used anymore.

pinout_alimentatore_commodore_64a.jpg.2a

Above shows the power plug that shows where the power comes in. I only use the 2 pins that are marked with the red box. So i'm using only those 2 pins directly soldered on the 15V DC powersupply. So Pin 6-7 is connected the other pins are NOT connected. The values mentioned in the pic are not used.

 

When i only connect the power supply to the MB6582 without any other connectors the MB6582 acts normal. So the power switch works how it should. If i connect a headphone to the MIX OUT connection the MB6582 still acts normal. But when i connect the MIX OUT (and any other output of the MB6582) to my External soundcard that the powerswitch does not act "normal" anymore. But the connections act like a power switch. Also if i connect it to any other "plugged in" computer/synth it does the same. So i gues a connection made with a "plugged in module" it will creat a closed power loop and thus switching "ON" the MB6582

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Hi Dreamer,

So u are shure that +15v is connected on the +site? where the bridge rectifier says +

The switch interups/closes one ac channel sounds like u switch Ground on /off instead of +15v.

then+15v is always there and so when another ground is introduced(other plugged gear) it will start up?

just a thought.

x

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Looking at the diagram here it's probably the expected behaviour, as +15V is always present. If the polarity was reversed the electrolytics would go pop and nothing would get through the regulators. So the next question will be about the 15VDC PSU, what is the model/do you have a picture? If it has a metal frame and earth pin, do you get continuity between it and the 0V line in the MB-6582? 

FWIW I did a similar mod on my build, but I use a linear (transformer-based) 12VDC PSU as input. This means that the device is electrically isolated via the transformer. 

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:)

On 13-4-2016 at 0:25 AM, latigid on said:

Looking at the diagram here it's probably the expected behaviour, as +15V is always present. If the polarity was reversed the electrolytics would go pop and nothing would get through the regulators.

Yep agree:)

On 13-4-2016 at 0:25 AM, latigid on said:

 If it has a metal frame and earth pin, do you get continuity between it and the 0V line in the MB-6582? 

 

if so a solution could be isolation(not connect) the earth pin in the 220v plug (stekker) or use a flat 220v plug(earth pin less en discard the 0v connection ),

if i'm correct..

x

Edited by X11
hazard

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Because the PSU chassis is plastic, I would say that the earth pin is not necessary. But this is mains voltage and you have to be careful... There's no easy way to remove the pin without hacking apart an IEC connector.

Can you try with a linear PSU instead?

EDIT: I don't advocate removing the earth connection if the device expects one. As we learned later, the OPs house uses non-earthed main sockets which clearly contribute to the problem. 

Edited by latigid on

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The only way for me to try a linear psu is by buying one. That is no problemen but if it isn't sure that it will solve the issue then its like throwing money in the garbage bin 

So looking around to see what kind of linear psu i can find. I came across this one i think this one is perfect for the job. Did not order yet, still waiting on other tips :D

http://nl.mouser.com/ProductDetail/Sola-Hevi-Duty/SLS-12-017T/?qs=sGAEpiMZZMtl%252b%2ft8G5TWgN7SYPj5Kq48atvObpxO30E%3d

Edited by dreamer
Looking for a linear psu..

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so i got some new info concerning this issue. I'm almost convinced now that it is not a faulty MB6582. This is what happened:

I decided to plug in the MB6582 into another wall outlet then my external usb soundcard just to try. And when i did this all problems are gone :angry:. Not sure how to proceed next. 

grtz

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There is no earth connection available in the room i'm in. All wall outlets here are without earth connection.

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If the wiring is very old, then earth might be connected to the neutral line. It's not very safe in any case. Sounds like you need an electrician to look at it rather than internet strangers.

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This kind of wiring is common in Holland only wall outlets near water or moist rooms have an extra earth connection. The wiring in my house is 25 years old i think

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Similar discussion featuring dutch houses,better to connect the pc and adaptor to an "earthed" outlet:

http://computertotaal.nl/forumarchief/1-moederborden--processors--overklokken--casemodding-en-koeling/73388-hoe-zit-dat-met-geaard-stopcontact

Same deal in my house so very interesting stuff (dutch-site).

Anyway good luck earthwise and congrats with your working MB6582:)

 

 

 

 

 

Edited by X11

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21 hours ago, dreamer said:

This kind of wiring is common in Holland only wall outlets near water or moist rooms have an extra earth connection. The wiring in my house is 25 years old i think

Well common for 'old' houses anyway. New houses have earth connection in all rooms.

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Hi all

 

On 15/4/2016 at 0:38 PM, X11 said:

what u can do is make a new cable for the adaptor with new plug and leave earthwire disconnected (probably the yellow green one).

 

Sorry to be harsh bust this kind of advise SHOULD NEVER TAKE PLACE !!!

It's again all safety rules, wrong understanding about this can be lethal.

We clearly see aluminium case at first pictures so it's clearly not a class II

YOU MUST KEEP SAFETY EARTH CONNECTED TO CHASSIS !!!!!!

 

Two wire wall outlet should only be used for class II equipment ...

 

Best

Zam

 

Edited by Zam

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7 hours ago, Zam said:

Hi all

 

 

Sorry to be harsh bust this kind of advise SHOULD NEVER TAKE PLACE !!!

It's again all safety rules, wrong understanding about this can be lethal.

We clearly see aluminium case at first pictures so it's clearly not a class II

YOU MUST KEEP SAFETY EARTH CONNECTED TO CHASSIS !!!!!!

 

 

 

You are right!

My mistake ill delete it.

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Hello X11

Thanks, it's a good decision.

Best

Zam

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