Jump to content


Photo

National RX-C300 amp chip ??


  • Please log in to reply
10 replies to this topic

#1 AZA

AZA
  • Members
  • 807 posts
  • LocationDown Under

Posted 12 November 2011 - 04:38 PM

Ok, so i took my RX-C300 to my repair guy.
It had the left channel out but right channel was fine.
He swapped the amp chip over to make sure this was the
problem and it appeared so. After moving the good amp chip
from the right to the left the left worked fine.

So next he ordered in a non original replacement
chip. But when fitting that chip he lost sound completely ??
Nothing at all :huh:
So he has put it on the 'back burner' for now while he tries
to make sense of it.
Now when he placed the order for a replacement chip he told
them what he required but he has noted that the original chip is marked
as a 'stereo amp' and the replacement sent to him is marked as a
'power amp' witha model # STK 4311 ?

Does this sound right or wrong ??
Can someone here make sense of any of this for me please ?

Thankyou :-)

#2 Superduper

Superduper
  • Boomus Fidelis
  • 6,165 posts
  • LocationSomewhere over the rainbow, USA

Posted 12 November 2011 - 06:19 PM

Wait. Are you sure? :dunce:

Because the RX-C300 uses AN7161 amps (23wpc x 1, dual btl) and it is a Panasonic chip.
The STK-4311 is a different module entirely, made by Sanyo. The former is only 12 pins. The latter is 18 pins. That would be like putting a square peg into a round hole. Actually, more like (2) square pegs into a round hole.

There must be a mistake somewhere. Do you have the model number correct? Or.... unless the National is different than the Panasonic which I highly doubt it would be that different.

If your tech needs a service manual so as not to be working blind, he can buy one from my website: http://www.Analogalley.com

#3 AZA

AZA
  • Members
  • 807 posts
  • LocationDown Under

Posted 12 November 2011 - 07:02 PM

Thanks Super.
This seems to explain a lot already !!

Im not even a Techs monkey :lol: so im only going by what he has told me.
The chip number and the 'power amp' reference is exactly what he told me.

He had questioned his supplier on the difference but was apparently
told by them that this was the correct 'non original' replacement chip ??

I will pass on the info you have given me thankyou and will also direct him
to your website.
Thanks again :thumbsup:

#4 Superduper

Superduper
  • Boomus Fidelis
  • 6,165 posts
  • LocationSomewhere over the rainbow, USA

Posted 12 November 2011 - 07:37 PM

Aza. The AN7161n chip is obsolete already. Only NOS chips are available. Those that are originial, old stock items, that were never sold.

However, NEW generic replacements are available via NTE, and their part number is NTE7011

It replaces both the AN7161N and the AN7161NFP That should be the correct chip to use. If it was me, I would probably replace them in pairs to ensure balance on both channels, especially if we are talking different manufacturer albeit "replacement" part. Differences, however slight, between the two channels would not be good.

#5 AZA

AZA
  • Members
  • 807 posts
  • LocationDown Under

Posted 12 November 2011 - 08:47 PM

Thanks again Super.
I can see this will def be getting me in the right direction to
getting it fixed :thumbsup:

Will follow up in the future with any results.

Thankyou

#6 Superduper

Superduper
  • Boomus Fidelis
  • 6,165 posts
  • LocationSomewhere over the rainbow, USA

Posted 14 November 2011 - 03:16 AM

Hey Aza, I 've been communicating with your tech. We have come to conclude that the National and Panasonic versions probably used different amp setups. So the STK-4311's are probably right for your National.

I already suggested your tech look into the chip he installed, whether they were fake/counterfeits. I have found this to be an increasingly common issue. I have personally experienced fakes blowing up when powered up wasting time, effort and money.

Check out this reading:
http://www.hometheat...ginal-fake.html

#7 AZA

AZA
  • Members
  • 807 posts
  • LocationDown Under

Posted 14 November 2011 - 03:27 AM

Hey, thanks Super !
I didnt know he was going to contact you but glad he did.

Thanks very much for sharing your knowledge and thanks
for the link, very interesting !!

I wonder what he will do now :hmmm:

#8 Superduper

Superduper
  • Boomus Fidelis
  • 6,165 posts
  • LocationSomewhere over the rainbow, USA

Posted 14 November 2011 - 03:44 AM

Well, your tech just emailed me and said the chips he got looked just like the ones shown in the article. :-O :lol: :lol: :grim: :-O :-O :no: :no: :annoyed:

Sorry, :blink: not funny and not sure what that means. But the ones depicted in the article apparently were fakes. I'm thinking he will need to order from a different supplier. It's really bull crap that we have this problem but you need to order, then take a chance, and if it happens more than once, it really becomes a pain. Is it something else, or is it the chip? You know what I mean? We have enough problems fixing things. It really suucks that we have to throw this into the equation too. And unlike transistors, etc, where we can actually check before we install, IC's are hard to check and verifiy. Once installed, hard to get your money back.

#9 AZA

AZA
  • Members
  • 807 posts
  • LocationDown Under

Posted 14 November 2011 - 04:36 AM

Crap..... if they look the same then that does not sound good.

At least the link you showed us helps make things a bit clearer !

I was also thinking that i have finaly found a local Tech who is
prepared to have a go at fixing my boomboxes and this situation
gets thrown into the mix :thumbsdown:

I still think he will have a red hot go at sorting them out for me though :yes:

He did mention about how far did i want to go at getting them sorted. Its a good
question really, where does it stop ? If you dont fix them.... then what ??

#10 Superduper

Superduper
  • Boomus Fidelis
  • 6,165 posts
  • LocationSomewhere over the rainbow, USA

Posted 14 November 2011 - 12:50 PM

ANYTHING with an stk amp chip in it is worth fixing. I think the much more common sony fh's might have the stk chip. The FH-7 uses the Stk-4026. Maybe the FH-5 might use the smaller 4011, not sure.

#11 National

National
  • Members
  • 15 posts
  • LocationWestern Australia

Posted 23 May 2016 - 08:47 AM

Wait. Are you sure? :dunce: Because the RX-C300 uses AN7161 amps (23wpc x 1, dual btl) and it is a Panasonic chip.The STK-4311 is a different module entirely, made by Sanyo. The former is only 12 pins. The latter is 18 pins. That would be like putting a square peg into a round hole. Actually, more like (2) square pegs into a round hole. There must be a mistake somewhere. Do you have the model number correct? Or.... unless the National is different than the Panasonic which I highly doubt it would be that different.If your tech needs a service manual so as not to be working blind, he can buy one from my website: http://www.Analogalley.com


In this case the Panasonic / USA models got the AN series monolithic output chips... The National / EU/Oceania sets got 2 STK4311 in btl for 2x56w (each 4311 is 2x 28W)