Voodoo Lab

Hi there...hope u can help me with a problem with my GCX.
It's been working just fine for about 5 years now...BUT....yesterday,when I tried to power it up the red leds just blinked once,I heard the internal relays clicking (as always) and just after that the unit went 'dead'...no leds on,no 'active' led on and ,of course,no midi commands go to or pass thru the unit.
My GCX is connected to a Ground Control Pro,which I removed along with all the cables,including the audio cables AND midi cables also in order to continue the troubleshooting procedure.The situation remained unchanged.Each time I try to power up,no matter what,the unit starts the power up sequence and goes dead just a moment after.
Any ideas out there?Could be a faulty power supply unit? Or maybe a faulty internal condenser ?
Thank you for your time.

It sounds like your GCX is actually powering up just fine. Power up, LEDs scroll from one side to the other, then it goes dark while it waits for either a SysEx message from a Ground Control to turn on the "Active" LED or a any MIDI message to flash the "Active" LED.

The MIDI cable between the Ground Control Pro and the GCX is the first suspect. Swap it out with another cable to test, if you can. Also, the MIDI Out on the Ground Control Pro is a 7 Pin DIN jack and it is possible to force a 5 Pin DIN connector into the jack with the pins misaligned. Be sure that the plug is inserted with the locator dimple at the bottom.

Let us know what you find!

Hey John...thanx for the fast reply on this.I have already done the midi cable change since it was the first 'suspect' but nothing happened.I mean still everything looks 'dead' both the GCX and the Ground Control (it doesn't even power up also)...BUT I will just make another try with a brand new,out-of-the-box midi cable just in case that the back-up cable I always have with me (the one I tried) is also bad.I'll get back to you with my further findings.Thank you again for your time.

Follow Up ...well,after all suspicions fell on the midi-cable,I ended up changing three different cables with no result...still the unit was 'dead' along with the Ground Control.Next step I took was to check the midi sockets,both on the GCX and GC...and that was it !!! I found that one of the cables on the midi socket of the GC had lost its continuity due to a corroded soldering (probably the one that actually gives power to the board).So the GC wouldnt power up and no midi commands to anything and no leds on to the GCX.After re-soldering all the pins just to be sure,things went back to normal and my rack is alive again !!!!!
I just forgot to take some pics just for reference use.
In any case,thank you for guiding me thru this !!!!!

That would be a first! Glad it's working, but be sure to let us know if you continue to have problems.

I am having this exact same problem. Gcx powers up but GCP stays dead. Powering the GCP separately there is no connection to the Gcx. Tried three separate cables that I know work.
The one thing I also notice that is concerning is that I have to wait a couple seconds between powering down and powering up for the gcx to reset. It may have always have been that way.... I normally turn it on and leave it till I'm done..... No rapid fire "on and off" so this pause may be normal.

I'll check the soldier points on the midi sockets. Seems this has had good results

Djay67 wrote:I am having this exact same problem. Gcx powers up but GCP stays dead. Powering the GCP separately there is no connection to the Gcx. Tried three separate cables that I know work.
The one thing I also notice that is concerning is that I have to wait a couple seconds between powering down and powering up for the gcx to reset. It may have always have been that way.... I normally turn it on and leave it till I'm done..... No rapid fire "on and off" so this pause may be normal.

I'll check the soldier points on the midi sockets. Seems this has had good results

For Phantom Power to work, the cable must have all five pins wired. Not all manufacturers wire all five pins.

Also, be sure to check that the MIDI Cable is oriented the correct way on the Ground Control Pro MIDI In. Look for the dimple on the shield portion of the connector and be sure it is aligned with the keyway in the MIDI Out Jack.


The GCX does need a few seconds to reset when powered down. This, at least, is completely normal

I have somewhat similar issue. When I turn on my GCX and GCP, GCX starts it's LEDs but my GCP is just flashing rapidly all LEDS and the screen. The only solution is to unplug MIDI cable and plug it back but that has to be done few times. Is there a procedure which one has to be turned on first?

valdoltra wrote: ↑

Tue Oct 15, 2019 6:12 am

I have somewhat similar issue. When I turn on my GCX and GCP, GCX starts it's LEDs but my GCP is just flashing rapidly all LEDS and the screen. The only solution is to unplug MIDI cable and plug it back but that has to be done few times. Is there a procedure which one has to be turned on first?

1. How are you powering the GCX?
2. Is the Ground Control Pro getting power over the MIDI Cable connected to the GCX or is it being powered from its included power adapter?

John,

I am powering GCX with original power supply and GCP is powered via MIDI cable. Could it be current issue, although GCX powers itself properly?

Cheers,
Vlado