Core Resets

[jwrigh10]

I have midified an organ. I can play for a minute or so and then the system resets. It will immediately begin working again. What could be causing the reset? I am powering it with a 500mA power supply set at 6 volts. (it said it is a 5 volt power supply, but the only options are 4.5v and 6v.) The power supply is connect to one core and that core is connected to another core on J11 terminal. I did not run power from the J2 of the primary core to the J2 of the secondary core as it is getting power from the cable. Any thoughts on why the system is resetting?

Jim

[stryd_one]

Do you have rectifiers and regulators stuffed?

Have a search for 'brownout'...

[matrigs]

try another 7805 - i had similar problems too.

[cimo]

hi

as S1 was pointing out you have probably 2 full stuffed COREs (i mean with rectifier capacitor etc), if this is the case 6 volts DC MAY not be sufficient, and those kind of supplies are usually not  very stable and their voltage can vary depending on the load (they don t use ICs), let s say that you could:

1- skip  the bridge rectifier

2- open the supply and connect the transformator aoutput directly to j1

3- buy a 9 volts AC transofrmer

4- get a supply with higher voltage at output

simone

[jwrigh10]

Thanks for the comments.

Being a Newbie, I have no clue what stuffed cores are  ;D

When you say "skip the bridge rectifier" are you recommending I desolder it from both cores? What if this doesn't work?

You recommend "getting a supply with higher voltage at output." The voltage supply I have can go up to 12 volts. Is that what you recommend? Would I burn something up if I increase it to 9 or 12 volts?

Is there a particular power supply you would recommend?

I don't mind purchasing another 7805 but I just hate to wait another 2 weeks to get it.

Jim

[nILS]

Being a Newbie, I have no clue what stuffed cores are  ;D

"Stuffed" in this case refers to the 7805 (voltage regulator) and the bridge recitifer which you wouldn't need if you fed the core with stable 5V DC.

When you say "skip the bridge rectifier" are you recommending I desolder it from both cores? What if this doesn't work?

Yes. If it doesn't work you can still soldering it back in ;-)

You recommend "getting a supply with higher voltage at output." The voltage supply I have can go up to 12 volts. Is that what you recommend? Would I burn something up if I increase it to 9 or 12 volts?

Perfect. 9V is a really good idea! Do that first. The regulator will drop the voltage to 5V. To do so it'll need some voltage to "drain". So if you're feeding it with <7V it may not work reliably. No need to worry about burning anything.

Is there a particular power supply you would recommend?

I'm using 10VAC, sth in that range (9-11VAC) seems to be the favored solution.

[jwrigh10]

Thanks for the replies. I tried 9v and 12v but still got a reset message. Will try to taking out the bridge rectifiers next. I assume I should still crank in 9volts with the bridge rectifiers out.

Jim

[nILS]

I'd probably start over by measuring the voltages w/o the ICs mounted as described on ucapps - just to make sure ;-)

[/tilted/]

Thanks for the replies. I tried 9v and 12v but still got a reset message. Will try to taking out the bridge rectifiers next. I assume I should still crank in 9volts with the bridge rectifiers out.

Jim

Do be very careful about this.

As you called yourself a newbie...

If you are using 9 to 12v, you shouldn't need to bypass the bridge.

The bridge recifier is there so that any momentary lapse of concentration (such as plugging in the power supply backwards), will not damage your core.

I say bypass the bridge ONLY if you are absolutely certain you will never plug the power in with incorrect polarity.

You may even have an intermittent problem with your power supply. Is it new?

[jwrigh10]

The power supply is about 6 months old. I do have another one that is 6v 800mA. I have not removed the bridge rectifiers yet. Should I try to find a 10vAC power supply instead. BTW, what I have is a power adapter. I don't know if there is any difference.

Jim

[cimo]

.since i was the one telling you to remove the bridge.. if you have a 9 volts supply don t do it! it s not necessary and not useful at all

[jwrigh10]

I won't remove the bridge. I did some experimenting and it seems that when I am pulling from just one core (e.g., Keyboards along) I do not get a reset message no matter how much I throw at it. Could it be that the cable which connects the core is losing some voltage? I was surprised to find that the J11 to J11 connecting cable powered the second supply. I thought you powered the other supplies by connecting the J2 connections to each other. Should I be doing both? Would simply having the second core powered by its own power supply be an easy fix?

Jim

[nILS]

Could it be that the cable which connects the core is losing some voltage?

In a way, yes, as the cable does have a *very* low resistance. Extremely unlikely that you'd notice though.

I was surprised to find that the J11 to J11 connecting cable powered the second supply.

Well any connection that has a Vd/Vs line will power a core obviously.

I don't think adding a seconds PSU is good idea. If you use the output of a 9VAC 1A supply (or something similar) you can just connect it to the first core's J1 and use either the J2-J2 or the J11-J11 connection to power the second core. If you do so, you can remove the rectifier, the 2200µF cap and the regulator from the 2nd core.

[jwrigh10]

I found a 3-12V Regulated 1000mA AC Adapter from Radio Shack. Would that do the trick? If so, do I have to remove the 2200µF cap and the regulator from the 2nd core? Is the amperage a major issue? I thought it had to 500mA. Also, is AC better than DC in this application? My PSU is DC perhaps that is my problem. Sorry to be such a pain! But I am learning alot!

Jim

[nILS]

AC or DC doesnt matter although with DC you tend to need a bit more voltage.

Amperage can be an issue. A core usually doesn't take more then 500mA. It just might for some reason, so having a bit extra is always good. The 500mA that are proposed on ucapps are to be seen as a minimum. Basically, the amperage can be seen as the "power" your PSU provides. The core(s) just take what they need from it. So if you supply it with 500mA and the first core eats 490mA you'll run into problems. If you supply it with 2A, you'd still have 1100mA "left".

[jwrigh10]

I may go ahead and get the Radio Shack supply. However, do I still need to remove the rectifier, the 2200µF cap and the regulator from the 2nd core or can I leave them?

[nILS]

You can leave them on the board.

[jwrigh10]

I tried a radio shack PSU with a 9VDC and 1000mA. Same result. Core resets when I play both keyboards and pedals. Am not sure which core resets or if both do it. I will replace the 7805's next and see if that helps. Any other suggestions would be appreciated.

jim

[nILS]

1) Remove the pics and optocouplers. Measure the voltages as described here

All okay? Then continue with

2) Try to find out which core is resetting. For instance by only using one core at a time.

3) Post the results here :D

[jwrigh10]

Sorry for the delay.

Here are the results from the core tests:

Core 1:

IC1 pin 1:4.99v

IC1 pin 11: 4.99v

IC1 pin 20: 4.97v

IC1 pin 26: 4.99v

IC1 pin 32: 4.99v

IC2: pin 8: 4.99v

Midi Out: 4.99v

Core 2:

IC1 pin 1:4.98v

IC1 pin 11: 4.98v

IC1 pin 20: 4.92v

IC1 pin 26: 4.99v

IC1 pin 32: 4.98v

IC2: pin 8: 4.98v

Midi Out: 4.97v

PSU set at 9vDC

Connected cores together at J11: Voltage tests consistent when tested individually.

Swapped the  PICS and Optocouplers between the two cores.

Ran MidiOX

Test 1: Both keyboards (Core 1): Okay. No resets despite large "hand fulls" of notes over several minutes

Test 2: Pedalboard (Core 2): Okay. No resets despite large "hand fulls" of notes over several minutes

Test 3: Connected Cores via J11 with PSU and MIdi cables attached to Core 2: Tested Keyboards alone: Okay.

Test 4: Connected Cores via J11 with PSU and MIdi cables attached to Core 2: Tested pedalboard alone: Okay.

Test 5: Connected Cores via J11 with PSU and MIdi cables attached to Core 2: Tested Keyboards and pedalboard: FAILED. Reset message appears after only 15-30 seconds. Occassionally, other messages such as "aftertouch" randomly appear.

Test 5: Connected Cores via J11: Tested Keyboards and pedalboard with PSU attached to Core 1 : FAILED. Reset message appears.

Test 6: Connected Cores via J11: Tested Keyboards and pedalboard with PSU and MIdi cables attached to Core 1 : FAILED. Reset message appears.

Test 7: Tested with another midi interface (Motu Fastlane USB) connected to faster computer (Pent. 4 Core 2 Duo): FAILED. This time multiple random messages appear such as "Piano"; "Electric Piano," etc.

I cannot seem to make one core reset. It only occurs when both cores are connected. They seem to get overloaded and random messages, including a system reset, begins to appear. Thought it could be an interface problem, but the use of a second interface seemed to rule that possibliity out. Any other thoughts would be appreciated.

Jim

[smashtv]

Connected cores together at J11: Voltage tests consistent when tested individually.

Swapped the  PICS and Optocouplers between the two cores.

I cannot seem to make one core reset. It only occurs when both cores are connected. They seem to get overloaded and random messages, including a system reset, begins to appear. Thought it could be an interface problem, but the use of a second interface seemed to rule that possibliity out. Any other thoughts would be appreciated.

Jim

Using two optocouplers while linking the cores via J11 causes random data.

From the CORE page:

J11:  MIDI digital IO port, interface to the LED/Thru/COM module. Can also be used to cascade multiple core modules in a long MIDI chain (see MIDIbox Link). Note: Don't plug the optocoupler (IC2, 6N138) into the socket when using the J11:MI (MIDI-IN) pin as an input, otherwise the Rx input will get the data from two different sources, which is not provided by the MIDI protocol (point-to-point). A MIDImerger is necessary to combine multiple MIDI IN sources.

In other words: when using the COM module or when connecting the J11:MO of one core module to J11:MI of another core module, or when connecting the core module directly with the Gameport, the optocoupler of the other module should not be plugged into the socket to avoid a corrupted MIDI data stream.

Best regards

SmashTV

[jwrigh10]

Removed optocoupler from first core unit: Still getting a reset message!

Removed optocoupler from both cores: Still getting reset message

Removed optocoupler from second core unit: Still getting reset message.

Checked sysex file and changed MidiMerge to "enabled" for both cores: Still getting reset message

Getting frustrated.  :-[

[jwrigh10]

My core reset issue has been resolved. Apparently, linking the cores using J11 is not the best for organ midification. When I linked the cores via midi cables, the problem disappeared. I also powered each core with its own power supply. Thank you all for your help. I am off to the next phase of my project-which will involved another midibox core!

Jim W.

[stryd_one]

My core reset issue has been resolved.

You mean it's been worked around ;) (see my sig, rules 2 6 and 7) J11 *should* work OK... Did you maybe forget to cross over the cables (MI-MO/MO-MI) ?

Still, it works! Yay!