Pioneer SX-680 issues.

[chrisand4]

I picked up an SX-680 today for $15. I got home and tested it, the left channel had no sound, only a hum. I decided to check the DC on the speaker terminals, nearly 15v on the left channel!

I've narrowed it down to a faulty STK-pack, I'm going to order a new pair and see if that solves the problem. If I get this receiver working right, it'll probably replace the 450 in my bedroom.

 

[markthefixer]

good luck!!

 

[Bstable]

I had a SX-680 that basically did the same thing. One of the channels didn't work and pegged the watt meter needle. I switched the STK module (easy)and the problem switched. Those STKs are available on the auction site which is where I got mine. I ordered 2 for a very low cost, but one of them was faulty from the get go. Seller had no problem sending me TWO more.

Be sure to get some of the thermal grease and apply it properly. I got some for $1 shipped. I also paid $15 for my 680, and for less than $15 had it working great. From what I have read here on AK, those STKs might not be reliable though. I ended up selling my 680 when a SX-3700 found me. I told the buyer the story about the STK repair and even gave him the extra STKs that I had.

 

[chrisand4]

I had a SX-680 that basically did the same thing. One of the channels didn't work and pegged the watt meter needle. I switched the STK module (easy)and the problem switched. Those STKs are available on the auction site which is where I got mine. I ordered 2 for a very low cost, but one of them was faulty from the get go. Seller had no problem sending me TWO more.

Be sure to get some of the thermal grease and apply it properly. I got some for $1 shipped. I also paid $15 for my 680, and for less than $15 had it working great. From what I have read here on AK, those STKs might not be reliable though. I ended up selling my 680 when a SX-3700 found me. I told the buyer the story about the STK repair and even gave him the extra STKs that I had.

Maybe it won't be a good replacement for my 450, which is very reliable.I'll probably keep both of them anyway.

I think I still have some arctic silver from a PC I put together, I'm sure it will work great as thermal paste

 

[markthefixer]

That is only one of the very very few places it shouldn't cause problems, BUT IF there's a mica insulator, DON'T use it!! It causes short circuits.

 

[chrisand4]

Just an update on this little guy, I got the power packs installed today. Now I have it driving a pair of Optimus 5B's and it sounds great!

I am very impressed considering how small it is, and considering it is pretty low on the pioneer totem pole.

 

[petehall347]

yep they can sound ok .well done fixing it .

 

[scottstevens]

I picked up a 680 recently and have the same problem the left channel doesn't work. I'm no means a technician but have some tools to do the job. I measured the DC on the speaker terminals at the back of the 680. I read .55 VDC. The right side measures .04 VDC. Same problem with STK? Is this STK0039 from what I found from googling. Thanks

 

[petehall347]

I picked up a 680 recently and have the same problem the left channel doesn't work. I'm no means a technician but have some tools to do the job. I measured the DC on the speaker terminals at the back of the 680. I read .55 VDC. The right side measures .04 VDC. Same problem with STK? Is this STK0039 from what I found from googling. Thanks

yes its the stk-0039.
before condemning it get the voltages for pins ..
0 1.4v
1 -1.4v
2 -30v
9 30v
3 0v
8 0v

 

[macyjrm]

I had the same problem with an SX-580 which I picked up for nothing out of a junk pile. Based on the knowledge of my fellow AKers and the fact the stk modules just snap into place, I replaced my bad one with great success. It now resides at my cousin's lake cabin driving a pair of JBL model 19s. We sure have had a lot of fun with that little fellow!