Help Marshall Valvestate 8040 issues

[Rich#6]

I have a old marshall valvestate 8040 that fades out and comes back. It doesn't do it a lot on the clean channel but does it non stop on the boost channel. Could it be the preamp tube?
I bought it last year and it's never worked right so I'm at the point of fix or dump.

[Twitch]

Could be the preamp tube. It could also be a loose connection inside. I just fixed my rhythm guitarists Randall for a similar problem. It would loose most of its volume for open chords but palm mutes would still be plenty loud but make the speakers sound blown. It was a loose connection of a cable that ran from the preamp board to the effects loop board. I reseated it and relieved tension on it by removing a couple tiny zip ties. Good as new. Seems your complaint is a common issue with this model, google it. It was mentioned on another site it could be a dirty return jack, but in your case its highly doubtfull as that would affect both channels. It couldnt hurt to try though.

[markD]

my friend had that problem in his 8040. turned out to be a broken solder joint. it was a $75.00 repair.

[DonP]

How much do these go for?

Rich,

I wish you lived closer. I'd take a look at it for you.

[Rich#6]

one just sold for 116 on ebay I've seen them go for 250. I paid 130 I think.