Behringer EM600 Echomachine schematics available?

[rock soderstrom]

Hi Group,

I got this broken EM600 delay pedal. No function, nothing, nada.


Any schematics available for this beast?

Cheers

 

[rock soderstrom]

from Behringer EM600 Echo Machine (Echo/Delay Stomp Box) - Review, Description, Info

 

[Whoops]

Does it turn on?

If it doesn't turn on at all then the fix might be simple

 

[rock soderstrom]

Does it turn on?

If it doesn't turn on at all then the fix might be simple

I haven't had time to really look at the pedal yet. What I can already say, it does not turn on, whether with battery or AC/DC adapter.

What I have already noticed, the battery gets hot because its shorted. Plus and minus of the battery clip have continuity!

This gives hope that the damage is not great.

 

[Khron]

What you could do, is power the thing from a current-limited bench supply. Cap it to 1-2A, turn it on, and see what gets warm. Could be as simple as a ceramic cap shorted or something - wouldn't be the first time.

Or, worse (not necessarily worst) case, the buck-regulator powering the digital circuitry crapped out.

 

[Whoops]

This gives hope that the damage is not great.

For sure, it's easier to troubleshoot the power circuit than the rest of the circuit

 

[Tubetec]

Theres a switched ground contact on the input jack for power , thats always worth a check .

 

[rock soderstrom]

Theres a switched ground contact on the input jack for power , thats always worth a check .

True! That was my first suspicion, unfortunately not the case this time.

 

[CJ]

Follow the batt leads to the nearest cap

 

[rock soderstrom]

Follow the batt leads to the nearest cap

Not so easy! Some of the PCB tracks are underneath other large components.

 

[rock soderstrom]

A short interim report after some time with the pedal. The diodes D1 and D2 were dead, when I remove them both the pedal starts, the blue LED is blinking. The electrical continuity of the plus and minus pole is gone.

However, there are other errors as the pedal does not show proper function. The original signal is looped through or muted with the blinking of the LED, an effect signal is not audible.

It need more TLC.

 

[rock soderstrom]

I have to buy a SMD diode. 1N5817 is in stock.

 

[Khron]

What was the SMD diode?

 

[rock soderstrom]

What was the SMD diode?

Good question. I took for a test a 1N4148. Both diodes a back in. Still the same problem.

 

[Khron]

Might wanna probe the output of the main buck converter - whichever side of the big inductor shows the lower voltage. Plural if there's more than one switcher chip.

 

[rock soderstrom]

Thanks, I'll add it to my list.
I suspect a faulty capacitor at the moment, the buffered bypass circuit works for a short time but the pedal tries to switch to effects mode all the time, in sync with the blue LED flashing.

The "foot" switch has no function at all atm.

 

[Admiral-dk]

Perhaps the most Common Error made by users (or who ever tries the pedal), is connection to the Wrong PSU ...!!!!

And here the usual Suspect is Wrong Polarity as almost ALL Guitar Pedals are using Centre Negative and the rest of the World are using Centre Positive .... !!!! # ¤ (( ....

Strangely enough, I see that a huge amount of Makers and Proffesional Manufactors are using an Anti-Parallel Diode across the DC Connector (and nothing in series between them !!! ) - In most of those cases, you just need to remove the Diode (failed as Short) and it works (better install a new Diode again). If the Diode fails as Open => Much more dammage
I have also seen quite a number tried on 12Vdc. and some popular IC's selfdestructs above +10Vdc - Usually 'Analog' (switched Capacitors) Voltage Inverters/Doublers are the problem ...!

Per

 

[jesseyasaitis]

I have an EM600 on my bench with a modulation issue. The modulation is always full on with no change in level with the mod pot. Is this pot a mix control or part of a VCA? On top of that, it's drawing .16A. My working model only draws .02A. Using a cooling spray, I noticed the DSP chip is getting hot. Probably a cap failed somewhere. Anyone happen to know the values of the caps that level the power coming into the IC's? Thanks much.

 

[Khron]

Before that, you might wanna consider checking (on the DSP chip's pins) what the supply voltage is. You should be able to easily find the relevant pins in the DSP's datasheet. No amount of capacitor swapping will cure a toasted chip, y'know...

 

[jesseyasaitis]

Before that, you might wanna consider checking (on the DSP chip's pins) what the supply voltage is. You should be able to easily find the relevant pins in the DSP's datasheet. No amount of capacitor swapping will cure a toasted chip, y'know...

Thanks Khron, that is a good point. I could see if there's a short from the Vcc pin to ground. Maybe I can get a programmed DSP from Behringer. I have the tools to remove and re solder.