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S30ztt

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Hi everyone,

I am just getting headache after headache with this blast. Initially the cab started with no audio and video. After toggling the rgb I started to get a picture and then slowly the sound came on. The minute I connect the marquee audio was shot but video was still clear. Naturally I think short and start checking grounds but everything looks fine.

I took the ms-2930 out for further inspection and check voltage- reading about 3v more or less at the speakers. Turner off and back on randomly and audio is back on.

Has anyone experience this? I am pretty much new to cabs in general so any help or feedback is appreciated.
 
Bad audio... really could be a lot of things. Hope you don’t mind a bunch of questions but it might help suss it out

Do you have multiple boards to make sure it’s not the pcb?

Have you recapped the power supply and amp? Guessing not if you’re new to this. Did the previous owner?

What is the loom/wiring that you’re using from the blast I/o to your pcb? Got photos? It’s something like this:

600-7143-001_01.jpg


And that loom can take in sound from two places, jamma and rca. Have you tried both?

Snap some photos. It’s provably not the speakers or the wiring to the speakers unless you fussed with that recently. It’s probably something between the pcb and the power/amp.

Are you saying it works if you remove the marquee lamp?
 
I don't have multiple boards but I did test the board on another pcb. The other pcb, however, did not have the marquee at the time.

Psu has not been recapped, looks pretty original. This may be my next step.

Loom is not the 001. Loom was tested on another cab with the same board and it was flawless. I'll take some picture of the wiring and post.

So I disconnected the marquee, checked voltage in speakers, and it after about 5 minutes the speakers started to work again. At this point I had the monitor out.
 
Psu has not been recapped, looks pretty original. This may be my next step.

Loom is not the 001. Loom was tested on another cab with the same board and it was flawless. I'll take some picture of the wiring and post.

So I disconnected the marquee, checked voltage in speakers, and it after about 5 minutes the speakers started to work again. At this point I had the monitor out.
while I can’t promise a recap will solve it, it’s certainly something you should do anyway! It does at least have a shot at fixing the issue, in my limited experience. If you want you could get another amp and check the speakers that way, but my guess is it’s amp/power related.
 
I've had similar problems that were caused by the crappy slide-in connector in front of the PSU.

Fixing it easy. Remove the four screws in the corners at the back of the PSU, pull it out and clean the pins of the connector. Do the same for the mating connector inside the cab. Rubbing alcohol and a toothbrush works wonders.
 
The marquee power supply is AC common with the CRT and PSU/audio amp at the I/O pcb, I wouldn't go down the rabbit hole with that.
 
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Yes, the marquee light has nothing to do with.
 
Thanks everyone, pulling out that psu for some cleaning.
 
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