Any advice on a Sony appreciated

[sashmo]

Hello,
I'm asking this one for a friend, an 80 something y.o. tech who is non familiar with forums and computers in general.
The patient is a Sony STR-DE-315 and he has just checked the output transistors mn2488 and mp1620 (all OK). It was recommended that the 0.22ohm and 180ohm resistors also be checked...I think I read that somewhere on this forum. I lurk a lot.

Now to the point...the 180ohm is in fact 220ohm and is the original part so would this be the norm for the 240 volt Australian model as apart from the US 110 volt?

I know I'm showing my ignorance of electronics but he's just done a fantastic job of renovation on my little Marantz 1060 so I owe him this favour.

Thanks

 

[jsimmo03]

Now to the point...the 180ohm is in fact 220ohm and is the original part so would this be the norm for the 240 volt Australian model as apart from the US 110 volt?

Thanks

It's a bit unclear to me what you are asking. I don't see why you'd have a different value resistor in the circuit for a 240V model. Maybe I'm missing something?

Does your friend have a schematic for this thing?

 

[sashmo]

Yeah, thanks for replying,
the schematic and all the advice we have states 180ohm BUT the resistors installed are definately original 220ohms. He can't see any reason for this so asked me to verify that it would be OK to use replacement 180ohms. Seems that I can reassure him to go ahead.
Thanks again

 

[jaycee]

It could simply be that a design revision was made and the resistors changed for that reason. To be sure youd need a proper service manual. In what part of the circuit are the resistors?

If they measure OK and test OK, why replace them?

 

[Mooly]

What's actually wrong with it.

 

[jaycee]

good question mooly - if it aint broke, dont fix it

 

[sashmo]

Seems that it has gone into protect mode and can't be unlocked without a remote. I've ordered him a remote on the net and while waiting he's checking out the other componentry.
So when he checked out the output transistors I drew his attention to a post on this forum which suggested that the dual emitter resistors and the 180ohm resistor next to it are a common problem as well.
That's when he found that the values were different and that's when he asked me (with my vast experience on tech. forums ) to ask you good people. Whew!