bad input jack/circuit board on my Marshall mg102fx

[topzpin]

Hi, this was originally posted in the blog section but I have moved it to the more appropriate Forum section.

on 03-24-2011 at 02:44 PM (65 Views)
I believe I have a bad input jack on my Marshall mg102fx. To be more specific I think it may be the very small circuit board the jack is directly attached to. From reading past posts I know the replacement part for the jack is Cliff jacks part #'s S-H504 or the S-H504L. Does anybody know what the replacement part for the small circuit board is and what it's function is? Thank you for any help you may provide.

Cottage - 03-25-2011 04:24 AM
The most common problem with this series is that the jacks come loose fom the circuit board and are intermittant. Resolder all the pads and see if that clears it up.

[topzpin]

I tried resoldering the pads. The problem still remains. On the small pcb there looks to be carbon on one of the very small chips. I would prefer to buy a new pcb, solder the jack to it and hope that corrects the problem. But I am not sure where to find the replacement part. Thanks again for any and all input.

[J M Fahey]

I very much doubt that you can get a replacement PCB.
Post a couple close up pictures, sharp and well illuminated, where tracks and values are clearly visible.
----> What exactly your problem is? <-----
Do you have a new jack to replace the old one?

[topzpin]

No, I believe it is a chip on the pcb. I have an electrical engineer looking at it. (Great friend to have). Finding the parts is the hard part. Thx for your reply!

[J M Fahey]

Then post the pictures anyway.
Still can't imagine what kind of "chip" can live on the small breakaway PCB normally used to hold the input jack.

[retgaz]

Have you tried contacting Marshall tech support?
I don't know what they're like in the US but I've always found the UK guys really helpful.
I'm pretty sure you'd be able to get the pcb from them, although you may not need it.
Like J M Fahey said, what is the problem?

[topzpin]

It took time but my problem has been fixed for free. The small PCB had a burned out chip on it. I have a friend who is an engineer. He was able to replace the small chip on the small pcb attached to the input. I found replacing the pcb was impossible due to not being able to find it. And believe you me I tried. The chip cost pennies the amp is back to normal and of course I am happy. Thanks to everyone who replied to this thread!