SX-1010 won't Power On...

[D.E.K]

I hooked the speakers to the "SPEAKER B" section and she has been working just fine for the past 10 mins. I am still losing sound. It gets real scratchy and a few pops, distortion and then dies out. Very seldom when I give it a jolt from 1 to 3, it comes back for 2 secs then same story. I am not going to push it any more since it is 5:45 AM. I am exhausted. Let's see what tomorrow will bring. Cheers.

 

[ccheath]

YA JUMPED THE GUN AGAIN!! :nono: This is where your excitement catches up to you. Don't dispair, it is expected even with it being old and very dirty inside. That's why Mark stated this: "You MUST not power up the unit until we have discussed more things,..."

Just relax and be PATIENT, Mark will get you there. You got hope. At least it did power up. You'll eventaully be playing it as I am with mine in living room. :yes:

 

[D.E.K]

Yeah I jumped the gun again. My bad. I'll wait for Mark's further instructions.

 

[markthefixer]

Now the ultimate test, hooking up the speakers and trying a CD player in AUX. Do I dare? Darn right I do!!

 

[markthefixer]

The FIRST CARDINAL SIN of working on electronics repair, ESPECIALLY in unfamiliar territory, is to work TIRED!!!! It would have been better to just knock off after building the dim bulb tester, and RECHECK your work the next morning when you are fresh.

The last guy that jumped the gun that badly BLEW UP his amplifier section.

THE NEXT STEP WAS TO TURN DOWN/OFF THE BIAS WHICH WOULD HAVE BEEN TOO MUCH FOR JUST TWO TRANSISTORS. I didn't want to load you down with too much, including finding the correct two pots of four. (I now know it's the one in the exact center of each amp board)

BIAS = HEAT, and too much heat causes thermal runaway, and with the old grease etc and unknown tightness of the transistors,I don't know how much heat they could take.

We would have done this bias adjustment after briefly powering up with NO SOUND, as the outputs are in a precarious state, with unknown heatsinking abilities, and continued ONLY if the protection clicked on, connecting the speakers.

With the bias off, we could have risked about a watt of output, which without bias would have sounded crappy.

Then we would have just let it sit with the volume off for a while and see if the protection continues to stay off. There's a lot of other circuitry that could go bad.

After a while we would have tried to set a low bias, and taken voltage readings in the amp to gauge it's health. An amplifier can pass some sound even when mortally wounded, until the outputs blow.

Right now the BEST thing to do is CLEAN the CRAP out of the circuits, who KNOWS what is being shorted out. That cleaning will take hours, paintbrush, vacuum, toothbrush and elbow grease time. At least the BOTTOM of the chassis should be cleaner.

I now have to stop and think about what you did and saw, and what damage could have happened and how to proceed from here. Did you put your finger on the transistors in back when you were "loosing sound", were they HOT???

 

[D.E.K]

No I haven't touched the transistors. Meanwhile, bad news, one limb of the right horseshoe broke off.

 

[D.E.K]

Jumped the gun like Chris said. Lesson learned. I lost the horseshoe on the right section and now I have 2 good and 6 bad transistors. Back to square -1. At this point I guess the best thing to do is just close her up and put it in the closet.

 

[ccheath]

Don't be discouraged. We all make mistake, including me(nearly killed myself working on black and white tv for it gave me a nice huge jolt). You broke the diode yes, but there are ways to replace it with other diodes even to just test it. 6 bad transistors, let's hope that's all that broke. It's still fixable. Mark can still get you fixed up, if you still want to. What do you say?

 

[D.E.K]

Thanks Chris. Of course I want to fix it. Sounded and looked fantastic while it lasted. And I thought I was doing good and learning fast. I got ahead of myself. Just a little pissed off at myself that's all.

 

[ccheath]

Thanks Chris. Of course I want to fix it. Sounded and looked fantastic while it lasted. And I thought I was doing good and learning fast. I got ahead of myself. Just a little pissed off at myself that's all.

I get that way sometimes too. Just relax take a break somewhere, then you can get back to what Mark say to do now is get that beast cleaned up. Then you can check back what more Mark has to say.

 

[D.E.K]

Will do, just not today. I will try to get to it sometime during the week.

 

[D.E.K]

http://toronto.kijiji.ca/c-buy-and-...turday-Lots-of-Stereo-Stuff-W0QQAdIdZ79849695

Wish I were in Toronto!

 

[ccheath]

http://toronto.kijiji.ca/c-buy-and-...turday-Lots-of-Stereo-Stuff-W0QQAdIdZ79849695

Wish I were in Toronto!

No you don't!! You wanna fix the ones you got. :yes:

I got the similar situation where I keep going to thrift store looking for any goodies (old gears) and going on eBay buying more even though I have several stereos that do need work. They were'nt getting worked on because the very money I spend on stereos could be used to fix the ones I got. Hey, hard to resist. I just made a recent purchase of a 20th vintage receiver. Couldn't resist that. Just a couple months ago, I finally was able to get parts for my SX-1010, they really add up. I got plenty of stereo that need work to keep me busy for awhile only if I keep up with the parts.

 

[D.E.K]

So is there a way I can get that horseshoe? Or a replacement diode of some kind?

 

[ccheath]

So is there a way I can get that horseshoe? Or a replacement diode of some kind?

Yes, there is a way to fix that. The "horseshoe" is STV-3H bias diode. It contains 3 diodes in one package. I recall finding it on internet but it is not so cheap as a diode. I recall it's around $12 or $13 EACH!! I read somewhere what diode was being used if the horseshoe was unavailable but it had been awhile and I can't remember what number it was. Markthefixer may know what to do if that "horseshoe" is unavailable.

 

[EchoWars]

http://www.partstore.com/Part/Kenwood/Kenwood/STV3HY/New.aspx

 

[ccheath]

http://www.partstore.com/Part/Kenwood/Kenwood/STV3HY/New.aspx

1/2 price ?? Gotta stock up for myself too.

 

[D.E.K]

Hi Echo;

Thanks a lot. $6.5 a pop eh. Hmm, I better not mess anything up next time I lay my coarse hands on the unit. First thing first, cleaning up the circuits and the chasis as Mark suggested. Speaking of which, is there a special way to clean the circuits without damaging any components, any solutions I can use? Also, taking out a few parts may help to get at hard to reach areas. Though, I don't want to take out the wrong part which might be almost impossible to put back in.

 

[ccheath]

I would start first using a clean paintbrush and compressed air. I would blow some air while brushing it. It should be alot of loose dirt off. Using Windex to clean the faceplate and knobs. I had success with that method on Kenwood KR-6050 some months ago. See pic. The KR-6050 was in a very clean environment is the reason. My SX-1010 I used a little more elbow grease, using windex to clean the chassis. I used 99.9% pure alcohol (electronic store carries them) and windex on the foil side(opposite of components) to clean off flux with success.


This is what Mark stated: "That cleaning will take hours, paintbrush, vacuum, toothbrush and elbow grease time." I'll add, "CAREFUL HANDS!!" On yours, I'd start with paintbrush and/or toothbrush and compressed air (if you don't have a compressor, use vacuum) first to get loose as much dirt before doing any "wet" cleaning. Just brush as you blow compressed air(or vacuum).

 

[D.E.K]

They don't ship to Canada