Markbass CMD121 cutting out

[StingRayBoy42]

At soundcheck last night, My Markbass speakers both cut out.

The FOH was getting signal from the DI out, but the speakers weren' working.

Turned off and on sorted it for about five minutes, then it happened again.

It's a CMD121P combo with an NY121 attached via Speakon.

I unplugged the NY121 and the combo on its own worked fine all night.

I play a StingRay through a Sansamp if that's relevant.

Any ideas what could be causing this?
Is it the speaker or the combo?

EDIT: The combo is pretty old - made in Italy I think.
There's no DI out level control.
 

 

On the plus side, the gig was pretty good.

Edited July 31, 2022 by StingRayBoy42

[BassBunny]

If the combo worked fine on its own I would suggest the problem is with the NY121 or the cable between the two. The combo could be going into a protect mode if the cable or extension cab have a fault.

I'd suggest trying a different cable first and see if that cures it.

[Lozz196]

Yep different cable, if problem persists someone opens the cab up to check wiring/connections.

[BassmanPaul]

Just for interest if the combo has an Effects Loop try connecting the Send and Return with a signal cable. See if that helps.

[StingRayBoy42]

I had Steve (the feller in Brum recommended on the amp tech thread) look at it.

He couldn't get it to go wrong despite having it running for a full day (!) so he replaced/cleaned/reseated/resoldered everything that could have been causing it.

I'll find out if it worked at the gig on Sunday.

[BassmanPaul]

Good luck with that then. I hope your troubles are over.

 

 

[Nebadon2000]

On 12/08/2022 at 15:24, BassmanPaul said:

Just for interest if the combo has an Effects Loop try connecting the Send and Return with a signal cable. See if that helps.

 

That's great advice for most Amps but Markbass Amps have a Parallel EFX Loop so sound will still go through to amp output even if loop or pedal plugged into loop has problem.

 

One of their reasons for using parallel along with main signal not being corrupted by signal passing through circuit, pedal and cords connected to it when not using pedal or loop.

 

PS; I read somewhere SMPS power supplies are more sensitive to Voltage irregularities pointing out Markbass. Not sure it is true or rumor.

Edited August 14, 2022 by Nebadon2000
added info

[synthaside]

This is exactly what's happening to my Combo right now , I have yet to take it to a repair person due to the intermittent nature of it and the fact that the only certified repair place just seems to swap boards . 

Hopefully you can figure it out and it can shed some light on mine too.

[BassmanPaul]

On 13/08/2022 at 20:52, Nebadon2000 said:

 

That's great advice for most Amps but Markbass Amps have a Parallel EFX Loop so sound will still go through to amp output even if loop or pedal plugged into loop has problem.

Well that was a waste of a perfectly good tiP!  I guess it must be time for my nap!