SX-1010 won't Power On...

[D.E.K]

Hi;

I just got this SX-1010. When I plugged it in it powered up, picking up stations, even the stereo lamp comes on. Next step, hooked up the speakers and I'm getting a few stations, weak but I am getting something and sound for that matter. Next step, Cd Player in AUX and no sound. I turn up the volume a little bit (up to 3 or 4 I guess) then I get sound for about half a second, like a big rush. After that, it's all darkness. I took out the fuse from the back of the unit, sure as heck, blown. I replaced the fuse, this time the fuse is okay but still nothing powers up. Quite frustrating. Any ideas, suggestions etc. will bu hugely appreciated.


Cheers;
Des

 

[markthefixer]

There are internal fuses, and if they blow after one replacement by you, technical assistance will be required. Start out from zero volume and turn it up, don't come up blasting.

 

[D.E.K]

Thanks a lot. Internal fuses hmm.. I think I can get at them but first I need to know where they are. I will gut her a little bit tonight. Just have to find the fuses that's all. I would appreciate a little assistance on the whereabouts of the internal fuses.

 

[markthefixer]

There are in plain sight, out in the open, in a row on one board in the bottom of the chassis, under the bottom cover, which also mounts the feet. Get the correct values, using a wrong value (bigger) fuse can cause very expensive damage. There is NO arguing or rationalizing this. It is a fact of physics.

Oh, and be SURE the power plug is UNPLUGGED when opening it up.

 

[D.E.K]

Cheers. The AC Power fuse at the back of the unit is supposed to be 6A, however, the only fuses that I could find were 6.3A and 7A. Do you think 6.3 would be too unfit to use?

 

[markthefixer]

Cheers. The AC Power fuse at the back of the unit is supposed to be 6A, however, the only fuses that I could find were 6.3A and 7A. Do you think 6.3 would be too unfit to use?

It's ok.

 

[D.E.K]

I removed the base plate. All the fuses seem to be fine, yet no power at all. Seems like she's totally dead. I am out of ideas at this point. Could it be the power supply unit? I am trying to link the problem to the volume knob but nothing. Looks like a waste of my $80.

 

[ccheath]

I wouldn't say it's a waste. I bought my SX-1010 for almost that much plus shipping. It needed alot of work even though it was working. I spent months working on it while I have the time. Now it's almost done and it already really shines. People say SX-535 has gobs of power but it only was rated 20. This SX-1010 really got the real gobs. :yes: Even if yours blew the output transistor, OnSemi make great outputs. I already replaced all mine.

 

[D.E.K]

Fact of the matter is, I don't have a clue how to replace anything on vintage equipment like the SX-1010 and there is nobody around in this town, or province for that matter, to fix old equipment. How can I replace output transistors?

 

[markthefixer]

Fact of the matter is, I don't have a clue how to replace anything on vintage equipment like the SX-1010 and there is nobody around in this town, or province for that matter, to fix old equipment. How can I replace output transistors?

Don't want to sound glib, but with a screwdriver, old rag, fresh thermal compound and directions....

But first you need to get a digital multi-meter and soldering equipment. You already should have the patience in stock, otherwise then it IS a lost cause.

You can download a .pdf of the service manual from here, and then you need to study it. And start reading repair threads on here. So we have a common language, there's a LOT to be learned from them.

Alternately, you could ship it to someone to get it (just) fixed or restored....
(with restored, it's pretty much like new, with another 20-30 years on the clock)

 

[ccheath]

I reread this thread and notice you replaced the fuse and this time it does not power up nor did it blow any more fuse. I would worry if its the transformer but I recall seeing in another thread about yet ANOTHER fuse, a slo-blo hidden somewhere by the AC line wrapped or partially wrapped in plastic. Echowar had replied that as a second protection in case someone put a 30 amp auto fuse in the main fuse holder. I can't positively recall if it was an SX-1010. I had not seen one in mine since I wasn't thinking to look for it while I was working on it. It's now closed up and being used until next time I start working on it.

If you did find that fuse and it's blown, then I'd check the transformer for any continuity and if good then check the output transistors.

 

[D.E.K]

Actually, yes I have noticed that fuse. It is in clear plastic and soldered on both ends. Though never checked it yet. I will in a bit.

 

[D.E.K]

Newsflash everyone. The "hidden", well not so very well hidden, fuse is blown to smithereens. I am planning on replacing it any trying again. The darn thing is, the hidden fuse is soldered on both ends and everytime it blows , I am going to have to de-solder the old one off and solder the new one on. I am not planning on blowing fuses all day long though.

 

[ccheath]

Interesting, it looks like a fast blow fuse. There's hope at this time because the power transformer is more likely okay. Do a continuity on the transformer primary with an multimeter. Don't power up anything at this time because something caused the fuse to blow.

 

[D.E.K]

I made an exception just this once and replaced the hidden fuse. Powered her up and she blows the main fuse (in the back of the receiver) although the hidden fuse is fine. :thumbsdn:

 

[D.E.K]

Also, if it means anything, there is no continuity between the two points I circled in the attached picture. It looks like one end is soldered to the large plate inside. Some kind of grounding??

 

[D.E.K]

Not the best condition...

 

[ccheath]

Also, if it means anything, there is no continuity between the two points I circled in the attached picture. It looks like one end is soldered to the large plate inside. Some kind of grounding??

It is the resistor. Not much of a concern. It has nothing to do with your problem. I looked at the pic of my SX-1010's AC line(see attached 1st pic). No fuse and different configuration. OOPS, forgot to reinstall the resistor back in mine. Gotta do that when I get back to it. I'm glad you sent yours, my pic of AC line would not be much of a help.

I'm getting the pics together. All my pics are rather too large to send because my camera is set high rez. I had to resize those three to make it viewable.

Not the best condition...

YEOW!!! GET 'ER CLEANED UP!!

 

[D.E.K]

Darn that is one sexy receiver! I will leave mine open for further steps to be taken. Just let me know when you're ready and set. Once again, when ready, just guide me through testing the continuity of the transformer. Cheers...

 

[EchoWars]

A lot of receivers of this era have two fuses...one, easily replaceable in the external holder, is a fast-blo fuse. The second, a pigtail fuse soldered in place inside, is the same amp value but is a slo-blo fuse, and is there to prevent catastrophic failure in case the fast-blo fuse is replaced with some ignorant value, like 30A 32V or something.