Home » Audio » Pro Sound » Marshall Valvestate 65 wont turn on anymore
Marshall Valvestate 65 wont turn on anymore [message #27062] Wed, 01 June 2005 20:20 Go to next message
Mike is currently offline  Mike
Messages: 29
Registered: May 2009
Chancellor
For awhile i had this amp that would cut in and out while im playing and it would always pop and crack before it was ready to have steady power going to it so it would work and have sound. I opened it up to see if there were loose wires or solder points anywhere but there wasnt so i put it back together and it still did the pop crack thing. So next day i try to turn it on again and it doesnt even turn on anymore.. it just seems dead. Im new to fixing amps and have the schematics for it does anyone know what the problem may be?

Re: Marshall Valvestate 65 wont turn on anymore [message #27063 is a reply to message #27062] Fri, 03 June 2005 00:04 Go to previous messageGo to next message
Mike is currently offline  Mike
Messages: 29
Registered: May 2009
Chancellor
ok dont know if anyones reading this but i made some progress.. i changed the fuse and a new preamp tube so i have power now.. itll turn on but not after like 10 minutes of cracking and power waving in and out.. especially at higher volume. when its steady itll start cracking and whatnot if i flick the power button. so what should i do that doesnt involve me putting any money into this thing when i want to get a new amp anyway.. resolder the board? something i dont know that has to do with the power supply? capacitors? any help would be appreciated

Re: Marshall Valvestate 65 wont turn on anymore [message #27064 is a reply to message #27062] Mon, 06 June 2005 18:46 Go to previous messageGo to next message
Chris R. is currently offline  Chris R.
Messages: 82
Registered: May 2009
Viscount
Without looking at it, my money is on power supply caps. Short
of finding a loose solder joint or being able to make it happen
by tapping on things with a wooden/plastic stick, you're likely
to need a 'scope to see where the transients are coming from.
Tube use high voltage, so be very careful. Only one hand near
the chassis at a time. The other one goes in your pocket.
Chris

Re: Marshall Valvestate 65 wont turn on anymore [message #27067 is a reply to message #27062] Tue, 07 June 2005 12:39 Go to previous message
KC is currently offline  KC
Messages: 4
Registered: May 2009
Esquire
I also have that problem with my JCM-800 lead series... Somtimes while im playing it will just cut out (especially annoying during band practice or shows) but then i take out the input to my guitar and it put it back in and its fine... this is very wierd and concerns me greatly. I thought it might have something to do with old tubes since its vintage and I have no idea when the tubes were last switched out. But good luck to you Mike.

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