jcM 900

[ALEXZANDEREPAIR]

Ok so I recently fixed my JCM it had a bad solder joint.Quick fix.
I then started on my long awaited combo amp for my JCM
After i was done with the cab then mounting the speakers.
I got NO SOUND!!!!!!!!!!!!! see before when my preamp had a bad solder joint I was getting power to the speaker and when I plugged into the effects return I was getting sound but now Im getting nothing to the speakers
The cabinet took me about a day and I put the marshall in and the speakers
but when I turned it on I wasnt getting any signal to the speakers but now when I turn it all the way up the transformer makes a slight buzzing sound
Im confused because it was working fine and wondering if When I was trying to get the marshall in the cab that maybe in the process I banged it and loosen something
I pulled all the tubes and placed them back in to see if they maybe got loose
then pulled the preamp board and did a visual check for loose solder joints did the same for the amp board
Im not to sure why something could have gone wrong by me just maybe knocking it around a bit.
I hope you can lead me in the right direction again.

[Enzo]

So connect the amp to a different speaker. With no sound, DO NOT crank the amp or you might destroy the output transformer. Seriously! Check the wiring, perhaps the speakers are miswired so there is no complete circuit, or they are shorted across by the wiring.

Touch a 9 volt battery to the speaker terminals for a second and see if they react.