Source SANYO STK1039 that is Geniune Part?

[ampexperts]

I serviced a Pioneer SA-303 last week. The SANYO STK1039 had a short from negative rail to output.

I sourced another one from ebay and installed it. The receiver made it through all diagnostic tests and seemed to be fine.

However, when the customer got it, he said the channel 'blew out' as soon as he turned it on.

I asked the ebay seller if the part was genuine or a Chinese counterfeit part. End result was a refund. I guess that answers it.

So now the receiver is back in the shop and I need to locate a genuine NOS SANYO STK1039 to fix it properly. If anyone knows of a source, please contact me. Thanks.

 

[RJM1]

No help, but I have just about giving-up on fixing anything with a STK output in it. 2 weeks ago I
had a friend who blew up his 30 year old Onkyo. The outputs were Sanyo STK4044V, I found that Dalbani in Miami still had them in stock, even though they had been discontinued. When the part arrived I noticed that it was physically smaller and the mounting holes were about 4mm off.I cut out the plastic screw holes on the STK and added a steel bar to hold it in place. ( PITA).
It's been working for him for over a week, lets hope it lasts.

 

[ampexperts]

I've replaced numerous STK devices over the years, with good results, but this is the first time one has come back for an immediate failure. Judging by the low price, it HAS to be a counterfeit part.

 

[davidsrsb]

The STK1039 is just a pair of darligtons and a Vbe multiplier.
No output protection so easy to destroy by abuse.

 

[nigelwright7557]

This website claims to sell genuine parts.
STK1039 - Modules,Purchase STK1039 online with free shipping | UTSOURCE

 

[davidsrsb]

This website claims to sell genuine parts.

Not many claim to sell fakes

 

[ampexperts]

I still suspect customer misuse, to some extent, since it worked perfectly after repair, while still in my possession. But the fact that the same channel failed again when the customer took it home doesn't sit well with me.

I'll check out that UT Source site. I've bought from them on ebay before.

 

[adason]

It's possible speaker on one side has defect with impedance too low...perhaps when you repair it second time, swap channels.

 

[ampexperts]

There's always that possibility. Customer claims he swapped speakers left for right and the suspect speaker worked fine on the remaining good working channel.

 

[davidsrsb]

Stray wire in a speaker cable perhaps?

 

[nigelwright7557]

Not many claim to sell fakes

Not many claim anything !

 

[nigelwright7557]

There's always that possibility. Customer claims he swapped speakers left for right and the suspect speaker worked fine on the remaining good working channel.

A bad speaker can still sound ok.
I blew one on a disco and the only thing that seemed wrong was a slightly lower level out of the bad speaker. When I measured it with a DMM the bad speaker was two ohms lower than the good speaker.
So it must have partially shorted out.