Is there any way to test a STK463 Audio Amp chip?

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Is there any way to test a STK463 Audio Amp chip? (without having some
sort of special factory analyzer)?

I had a Marantz SR1000 receiver given to me. I plugged it in, and got a
few seconds of hum, panel lights dimmed also. Then smoke appeared. I
found the source of the smoke, a small electrolytic cap blew, and left
the board wet.  

I may try to replace that cap, but I suspect there is more wrong. I dont
usually work on anything containing IC chips. And Im sure if that big
amp chip is bad, it would be very costly. (Not worth my time or money).  
But I'd be willing to test it if I know how.

By the way, the power supply is working. As soon as I unplugged it
(after the smoke), I got a good spark when I shorted the main (large)
filter caps.


Re: Is there any way to test a STK463 Audio Amp chip?
On Thursday, April 18, 2019 at 8:01:25 PM UTC-4, snipped-for-privacy@myshop.com wrote:
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Please post the cap that smoked.  Its location will help us to provide guidance on repairing this unit.  If the STK is bad, a new one can be obtained for $10-$15.

Dan

Re: Is there any way to test a STK463 Audio Amp chip?
On Thu, 18 Apr 2019 19:18:22 -0700 (PDT), snipped-for-privacy@yahoo.com
wrote:

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on repairing this unit.  If the STK is bad, a new one can be obtained
for $10-$15.
Quoted text here. Click to load it

Will post it when i am back at the shop. I am currently looking for a
schematic to download. Thus far im not finding any.

Thanks

Re: Is there any way to test a STK463 Audio Amp chip?
snipped-for-privacy@myshop.com wrote:

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** FFS use Google.com and " STK463 schem "  

   Wot a pathetic retard.  



....  Phil  


Re: Is there any way to test a STK463 Audio Amp chip?
On Thu, 18 Apr 2019 19:18:22 -0700 (PDT), snipped-for-privacy@yahoo.com
wrote:

Quoted text here. Click to load it
 on repairing this unit.  If the STK is bad, a new one can be obtained
for $10-$15.
Quoted text here. Click to load it

The blown cap is C807. Its.connected in the area of the Q805 transistor,
which I am guessing is a voltage regulator (maybe)???? Appears to be
10uf at 50v.

I have not found a schematic for this unit so I'm in the dark on it....
But this is in the power supply area.

I have watched several videos on YT about similar units that use the STK
modules. It seems they work well, until they fry. Then all hell breaks
out. The other caution is that many of the after market STK mods are
fakes, which do not work.

I will also mention that in the 80's, I worked on a Fisher stereo that
had a STK mod. Back then these mods were costly. I bought a replacement,
it burned up instantly. (And yes I had checked power supply voltages and
all of that before powering it up). Theres a video on YT in which some
guy had the same experience. On that one I worked on in the 80s, I spent
many hours, and lost a lot of money on it. Actually, that was when I
quit working on other peoples gear.  

I ended up stuffing a amplifier board inside that stereo, from another
device, just so I could hand the owner a working stereo. It worked but
only produced around 5watts per channel. The owner was satisfied, but
not highly impressed by the low power.  

Needless to say, I do not have a very good impression of those STK
modules, overall.

Aside from that, since this thing cost me nothing, I'll play around with
it, and will stick a few bucks in it for caps and such. After that it
will just become a pile of salvagable parts...... While its a nice
looking device, its not worth much effort or money to me.  

Note: Before posting this i did find a schematic.....


Re: Is there any way to test a STK463 Audio Amp chip?
. Back then these mods were costly. I bought a replacement,
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You need to learn the technique of  using a Variac or a light bulb in series with the AC input to test before applying full power.

m



Re: Is there any way to test a STK463 Audio Amp chip?
Let me set this to rest. That IC has + and - inputs. Treat it like an OP AMP.  

Know how to troubleshoot an OP AMP ? this is the same thing only bigger. It also might have booststrap caps and maybe some bypass, but even without them it should kinda work.  

Re: Is there any way to test a STK463 Audio Amp chip?
wrote:

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It is a pretty decent receiver. It wasn't made by Marantz in the U.S..
It was manufactured by Standard Radio in Japan.

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