technics amp

[shaggy1978]

i have a technics sua700mk3 amp that keeps blowing the internal fuse with nothing conected no scorch marks on the curcit board any sugestions? ps i carnt spell

 

[davenn]

hi there
welcome to the forums

specifically which fuse is blowing ? is it the one on the mains power input labelled F1 T2A ? or is it one somewhere else in the unit ?
I found a service manual online so if you can tell me where that fuse is I may be able to help

when you say "nothing connected" I assume you mean the speaker lines and inputs ?

Dave

 

[shrtrnd]

I'm not familiar with the model described here, and like davenn said, it matters what
fuse you're talking about (power or speaker fuses).
My comment is I've run across a couple of amplifiers over the years that will blow
fuses if you turn them on without any load.
Check your owners manual, make sure it's ok to power the unit up with no load.
Or that you don't have the power control at a very high setting when you power the amp up.

 

[docb]

Is it discrete or an IC for the power amp section?

 

[davenn]

the power amp is an IC module

The OP still hasnt returned to answer my questions

Dave

 

[shaggy1978]

sua700 mk2

cheers dave and sorry for the delay computer probs) yes its the main fuse f1 1.6amp on the power board . if the unit is on standby its fine but as soon as you turn the amp on flash gone fuse blown . and yes nothing connected means no speakers or inputs or outputs. any help much apreciated. ps were is spell check? when the problem first happened it was connected to all the out puts as it has been for years. i am new to these forums and dont understand some of the terminology used sorry and please bear with me

 

[shaggy1978]

Is it discrete or an IC for the power amp section?

not sure what you mean by this.

 

[davenn]

Is it discrete or an IC for the power amp section?

not sure what you mean by this.

discrete = individual transistors

IC = power module IC ( Intergrated Circuit)


But as I responded a few posts ago its an IC power module rather than discrete devices


Dave

 

[docb]

Since you have no varaic, I'd start by desoldering the output IC, and see if power comes on without blowing the fuse.