Bringing my dad's SX-980 back to life.... need a little help!

Keymaster

Keymaster

Active Member
My dad's SX-980 had been sitting in his listening room for over 15 years and it had always bothered me. When I got into vintage stereos a few years ago and found this site, it made me want to rescue it. The reason he decommissioned it was because one of the channels would pop in and out....probably from dirty pots. He had it serviced once at a local shop and the fix only lasted a few months before he had the same issue reoccur. So he bought a newer receiver around the mid/late 90's that pushes his HPM-100's just fine. But of course, it's just a huge, black hunk of plastic with no character. :D

So a few weeks ago, I told him that I could probably fix that scratchy, intermittent channel issue and bring this beast back to life. Last night, I finally had time to open her up and get to those pots. The good news is that, for the most part, she sounds great and there's no scratchiness in the controls. I Deoxited the controls per the "Idiot's Guide" and I think I'm about 95% there.

Here are my issues:

1. The right channel cuts out when I put the receiver in "Stereo". In Mono, it plays out of both channels. I've read on here where others have had the same issue. My question about this is, can I Deoxit this type of switch (the up/down switch) cleanable from the front (with the face plate off) or is there a hole (like the turn-able switches, ie. volume, treble, bass) that I need to reach from the inside? The turn-able, knob controls clearly have a little notch that you can see from the rear, on the inside, but the up/down switches, not so much. I have sprayed the Stereo/Mono switch twice, but still no luck. The right channel (in Stereo) doesn't play in FM OR Aux. It actually sounds good in Mono, but I know something is wrong and I don't want to give this back to him until I've found this issue.

2. What is the best way to remove dust from the inside? I am going to pick up some compressed air today, but there is some caked-on stuff that I'm sure won't come off with air inside of this thing. Is it okay to wipe off the big caps and such with a clean, dry rag? Also, is it okay to spray Deoxit on the boards to help clean away any dust?

3. I have used hot water with some Simple Green and a tooth brush on the face plate. My dad is a heavy smoker and this thing is caked with nicotine. It's helping but it's still not getting it all off. Is there something else that will take that nicotine off without being too abrasive? I plan on putting a polish on the face plate once it's clean, but it's surprising me how hard it is to get this nicotine off.

Thank everyone for their assistance with this. I'm super-exited with the process so far. I'm hoping to have the stereo and wooden case finished for him by his birthday in late September. :music:

Chris
 
Keymaster said:
I have sprayed the Stereo/Mono switch twice, but still no luck. The right channel (in Stereo) doesn't play in FM OR Aux. It actually sounds good in Mono, but I know something is wrong and I don't want to give this back to him until I've found this issue.
Click to expand...

No stereo in AUX is a good hint. That likely means the problem is before or in the flat amp, and the fact that AUX doesn't work in stereo may mean the FM section is intact.

Thoroughly clean the DUPLICATE, MONITIRO1 and MONITOR2 switches ans exercise them just like the MON/STEREO switch.

Just for grins you could try whatever source is plugged into the AUX inputs in the TAPE playback inputs (1 and 2) to see if the stereo works in those modes.


2. What is the best way to remove dust from the inside? I am going to pick up some compressed air today, but there is some caked-on stuff that I'm sure won't come off with air inside of this thing. Is it okay to wipe off the big caps and such with a clean, dry rag? Also, is it okay to spray Deoxit on the boards to help clean away any dust?
Click to expand...

It is safe to wipe away the dust, but a fairly easy method is to us a cheap paint brush that has had the bristles cut short so they are stiffer, then knock the dust and debris loose with that. A blast of air should get them out of the unit after they are loosened. A really bad unit may require disassembly and a hot water/soap washout, followed by a thorough drying.


3. I have used hot water with some Simple Green and a tooth brush on the face plate. My dad is a heavy smoker and this thing is caked with nicotine. It's helping but it's still not getting it all off. Is there something else that will take that nicotine off without being too abrasive? I plan on putting a polish on the face plate once it's clean, but it's surprising me how hard it is to get this nicotine off.
Click to expand...

What you are fighting is tar, not nicotine, and if can be softened with isopropyl alcohol and a hot water rinse. Abrasives are a no-no since they risk removing the labels and damaging the anodized aluminum finish. When I get one that bad, I usually remove the faceplate completely to wash is in very hot water both outside and inside - The inside of the glass is likely almost as bad as the outside of the face.
 
Watthour, thank you so much for the reply. I plan on picking up some compressed air and I can grab a small paint brush while I'm out. The inside isn't so bad that a complete wash-job is necessary, but if I can break up the stuff covering the top of everything and then blow it out really good, I think that will help tremendously.

As far as the mono switch, I'll hit those Monitor switches to see if that helps. Since this receiver hasn't been used in almost 20 years, I'm sure they could use more cleaning.

Chris
 
ANYTHING that goes in n out, up n down or roundy round needs deoxiting with follow up faderlubing. NOT faderlubing the pots will be fatal for the pots in very short order after deoxiting - because all the vital lube is washed out. Everything else is a protectant and preservative move.

The deoxit MUST make it to ALL the contacts in each switch.
 
markthefixer said:
ANYTHING that goes in n out, up n down or roundy round needs deoxiting with follow up faderlubing. NOT faderlubing the pots will be fatal for the pots in very short order after deoxiting - because all the vital lube is washed out. Everything else is a protectant and preservative move.

The deoxit MUST make it to ALL the contacts in each switch.
Click to expand...

Will be picking up some faderlube as well. :yes:

I'd always heard of using the Deoxit but it's definitely worth the extra effort to lubricate them after they're cleaned.

I'm pretty excited about this project. Other than getting the tar off of the face plate, the receiver is in good shape. My ol' man treated his stereo equipment like a third child back in the day. The cabinet is in great shape and will just need some refinishing. The knobs, after soaking in Simple Green overnight, came out sparkling. It's gonna look almost new once it's complete.

Thanks again for your suggestions.

Chris
 
While lubricating with Deoxit the other night, I worked the tuner dial back and forth after and noticed that it gives a creaking sound during certain portions of the dial. Is this where the wax that people refer to comes in? Does that alleviate the creaking? The string seems to be fine and doesn't appear brittle, but I remember as a kid that you could give the dial one good spin and you could go from one end to the other. Definitely can't do that now.

Also, is there a brick-and-mortar store that sells the faderlube? I checked a couple of Radio Shacks here locally and they sell their own brand of lubrication. They have Deoxit, but just the cleaner. If not, it's no biggie, I see several places online that carry it.

Thanks,

Chris
 
Watthour said:
No stereo in AUX is a good hint. That likely means the problem is before or in the flat amp, and the fact that AUX doesn't work in stereo may mean the FM section is intact.

Thoroughly clean the DUPLICATE, MONITIRO1 and MONITOR2 switches ans exercise them just like the MON/STEREO switch.

Just for grins you could try whatever source is plugged into the AUX inputs in the TAPE playback inputs (1 and 2) to see if the stereo works in those modes.

Watthour, you are the MAN! I hit those 3 switches again, thoroughly exercised them, hooked back up and, voila! It's like magic, only it isn't! LOL Checked FM and we're good there as well.

The only thing now that concerns me as far as the mechanical aspect of the receiver is the FM reception. I live in the Richmond, VA area and there are several stations that put out a fairly strong signal. I'm barely able to get enough on one of them to get the stereo light to come on. All other stations teeter around 1-2 on the strength side and I can get close to the tuning range but not quite. Now granted, I'm using a piece of speaker wire for an antennae but I've always had good luck with that before. Any suggestions on that would be great.

As always, thank you!

Chris
Click to expand...
 
Dawn and warm water works wonders on nicotine stains. I spent hours on a Kenwood Eleven (tons of knobs) with different cleaners trying to remove 30 years of nicotine (guy never opened a window). Member Boatdrinks took 1 knob off, spent 4 seconds with dawn/water and it was sparkling.
 
Key,

Apply some beeswax to the tuner cord with your fingers, trying to work the thin wax into the strands of the cord. Then exercise the tuner from end to end several times to distribute the wax. It might also be a good idea to apply a few drops of oil (3-in-1, Tri-Flow, or something similar) to the tuning spindle bushing and the tuning string guides. More about lubrication a little later, but your FM reception issue will need to be addressed first.

Since you've mentioned that the unit has some internal contamination, it may be helpful to use your stiffened brush and isopropyl alcohol to clean the fins of the tuner VC assembly. Contamination on that can alter the capacitance of the plates and really affect signal capture, as well as the IF and local sections. It can also be helpful to clean the insulators and area around the trimmer capacitors along the top of the tuner assembly. Be very careful to not move any of the adjustments, and to prevent any damage to the thin mica insulators surrounding the trimmers. Nothing will be of much help unless the plates and trimmers are cleaned and dried thoroughly. The alcohol may take more than a day to dry out, so be patient.

Once the VC is clean and dried, a bit of oil should be applied to the bushings and gears of the tuner VC. Avoid getting any oil on the tuner plates/fins themselves. If you can CAREFULLY apply some oil to the bronze bushings and spring plates of the tuner shaft, that would also be useful. It can usually be done safely by dipping a toothpick in oil and applying one drop at a time to the critical areas without getting any on the VC plates.

As for the FM signal, connect a decent dipole antenna, using a length of speaker wire folded open into a "T" about 30" long. If the tuner VC cleaning and reasonable antenna don't improve reception and you are confident in your ability to perform a few adjustments, there are some instructions for a crude tweaking of the tuner section which can help reception. Unfortunately, there is an equal chance of desensitising the tuner to the point of making it useless without sending it out for a full-on alignment.

For adjustment, a reliable voltmeter, some hex and straight alignment tools, and a signal source would be necessary.
 
Faderlube

You can get the Faderlube at the Guitar Center on West Broad Street, just past West End drive. It'll be about $20. There is another music store, Sams, that sells turntables and prof audio stuff in the immediate area.
 
buttahman said:
You can get the Faderlube at the Guitar Center on West Broad Street, just past West End drive. It'll be about $20. There is another music store, Sams, that sells turntables and prof audio stuff in the immediate area.
Click to expand...

That's great, thanks! I can head over there during lunch today. :D

Just checked their website, they have it on sale for $15.99!
 
Last edited:
Well, I was able to go pick up some faderlube this afternoon at the local record store. Thanks to buttahman for the heads up on that. And to top it off, it was on sale for $9.99! Got home this evening and sprayed them down and exercised them one more time. Let it sit a bit to let things dry out.

Since I have have working on this particular receiver, I have tried to play music that my dad would have played. Not surprisingly, much of what I listen to today is music that my dad played in my younger years. After yesterday's initial cleaning, I threw on some Little River Band - Lonesome Loser. Sounded great. After hitting it with the faderlube this evening I decided to put on some Bob Seger - Mainstreet. That, apparently, hit a nerve. As in, I'm gonna close the door because if my wife or kids walk in, they're gonna want to know what is wrong. It's just something about seeing those needles moving to the music and hearing something that takes me to another time and place....which is pretty much what music is all about. My gut feeling is that I'm gonna be even more emotional when I give this to him. I was going to wait until his birthday at the end of September, but I don't see the point in waiting if I finish it sooner. He hasn't been in the greatest of health and I think that seeing this play again with those HPM-100's that he has will be a real pick-me-up. :music:

I took a brief video of the receiver playing with my small Advents. I'm gonna show him how it's coming along next time I see him, hopefully this weekend.

Thanks again for everyone's help,

Chris

http://youtu.be/ikaFs9kXPbw?list=UU7-yloK10TQ8Bu_jvqJ03XQ
 
Chris; With the FRONT PANEL OFF, If you look closely at the front of the push button switches you should see a hole in one or more of the corners. Spray the DeOxit in there while exercising the switch. That should ensure it gets to all of the contacts in them.

Once you get everything cleaned up and looking good, check the amps for correct center voltage and idle current. It's in the manual page 25.
 
I love threads like this. I know it is going to floor him when you lay this sweet gear back into his possession.

Rock the hell on.
 
Face plate is silver again!

On the suggestions of many here, I picked up some Blue Magic Metal Polish today. I was a little worried the other night because, after using Simple Green and Dawn dish washing liquid, it still didn't look "clean". Well, after a couple rounds with the Blue Magic, it looks silver again! I'm attaching a couple of pics to show a before and after. The one pic is when I first brought it home and sat it on top of the 780 that I tried fixing but never successfully did. You can see around the volume just how bad the tar stains were on this. The first coat of polish was the most dramatic. When I wiped it off and looked at the rag, it was yellow, like I had just wiped wet, yellow paint off of it. Amazingly, there is one tiny scratch between the FM and AM buttons, but that's it. The dials and knobs turned out so well, I wasn't sure if I needed to polish them, but I may just do a light coat on all of them just to put a small layer of sheen on them. :D

I also picked up some steel wool and some flat, satin paint, so I'll head out to the garage shortly and start working on the wood cover. It's in good shape as well, just need to steel wool the layer of tar off of it and put some Howard's on there and she'll be good to go. :thmbsp:

Chris
 

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Keymaster said:
On the suggestions of many here, I picked up some Blue Magic Metal Polish today. I was a little worried the other night because, after using Simple Green and Dawn dish washing liquid, it still didn't look "clean". Well, after a couple rounds with the Blue Magic, it looks silver again! I'm attaching a couple of pics to show a before and after. The one pic is when I first brought it home and sat it on top of the 780 that I tried fixing but never successfully did. You can see around the volume just how bad the tar stains were on this. The first coat of polish was the most dramatic. When I wiped it off and looked at the rag, it was yellow, like I had just wiped wet, yellow paint off of it. Amazingly, there is one tiny scratch between the FM and AM buttons, but that's it. The dials and knobs turned out so well, I wasn't sure if I needed to polish them, but I may just do a light coat on all of them just to put a small layer of sheen on them. :D

I also picked up some steel wool and some flat, satin paint, so I'll head out to the garage shortly and start working on the wood cover. It's in good shape as well, just need to steel wool the layer of tar off of it and put some Howard's on there and she'll be good to go. :thmbsp:

Chris
Click to expand...

Blue Magic works for me every time, no matter how much tobacco smoke is layered on the faceplate.
 
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