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Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => The Newcomer's Forum => Topic started by: Dankou on January 25, 2011, 01:18:39 PM

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Question: peavy studio 40 amp transformer bad?
Option 1: newcomers forum votes: 0
Option 2: solid state amps votes: 0
Title: Amp Repairs
Post by: Dankou on January 25, 2011, 01:18:39 PM
Peavy studio 40 amp transformer bad?
I pulled the board and seem to have no DC output
and idea where i might get specs and or replacment
tring to find the schmatic here no luck as of yet
 Thanks for any help
                                Dan
Title: Re: Amp Repairs
Post by: J M Fahey on January 25, 2011, 02:45:54 PM
Is that transformer primary getting power?
Isn't the fuse blown?
With the amp unplugged, measure resistance across power plug hot and neutral pins; with power switch "on", of course..
Title: Re: Amp Repairs
Post by: Dankou on January 25, 2011, 06:14:28 PM
Thanks for reply
Measured voltage going in to transformer 120V AC checks OK
get no voltage coming out (I suspect DC voltage but checked AC voltage as well
checked fuse has continuety
I have pulled transformer already
standing alone it has continuety between AC input wires
as well as output wires as well
would it be worth my while to reassemble an check resistance or can i assume it has no resistance
if it shows continuety
transformer is marked Peavey 705-18712
                            Thanks for you help ........Dan
Title: Re: Amp Repairs
Post by: J M Fahey on January 25, 2011, 06:33:58 PM
*if* the primary shows continuity and secondary too, feeding 120VAC to its primary should produce "???" VAC on the secondary.
Draw a simple schematic showing the transformer and the wire colors.
When hooking the transformer use the original amp wiring (switch and fuse) and check that you still have continuity between power plug legs.
Maybe the transformer is fine, but 120V do not reach it.
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