My Vintage HiFi needs help

[Bermi]

Hi, I'm new here.

I have a problem with my 45 year old Vintage HiFi. The Amplifier (Nikko trm 500 stereo) is the problem, as it works in Mono, but in Stereo, the right speaker doesn’t work. Is it something that can be repaired? If so, are parts for it still available?

I have rarely used the HiFi in the last 25 years. My Apan BFU-121 Turntable works perfectly and my Richard Allan Speakers still sound great. The Amplifier is the problem.

I will be house downsizing soon, so I am wondering if it is worth keeping.

[surprisetech]

13 hours ago, Bermi said:

Hi, I'm new here.

I have a problem with my 45 year old Vintage HiFi. The Amplifier (Nikko trm 500 stereo) is the problem, as it works in Mono, but in Stereo, the right speaker doesn’t work. Is it something that can be repaired? If so, are parts for it still available?

I have rarely used the HiFi in the last 25 years. My Apan BFU-121 Turntable works perfectly and my Richard Allan Speakers still sound great. The Amplifier is the problem.

I will be house downsizing soon, so I am wondering if it is worth keeping.

The Nikko gear was pretty decent.  Well designed and well built.

The fault you describe could be something simple and worth getting repaired, but if the amplifier output stage has died, or there is another electronic fault that requires some time to diagnose, then it might not be cost effective.

 

Have you swapped the speakers & speaker cables to confirm that the amplifier is definitely the problem?

If so, then with power disconnected, firstly check the speaker wiring on the channel that is not working.  Make sure that the wires are all terminated properly at both ends and that there are no loose strands of wire that might have shorted to the other terminal.

Then check if one of the circuit breakers on the rear panel has activated.  If any have popped out, press it back in.  Reconnect power and test.

 

If that doesn't fix the problem, then the next step would be to clean the switches and controls, particularly the Volume control, speaker selection switches and the "Connect/Separate" switch on the rear panel.   That involves removing the cover and treating them with a contact cleaner spray (NOT WD-40), so should be done by someone competent in that area.

 

Beyond that, further fault finding would probably involve test equipment & a soldering iron and a suitably qualified technician.  If you let us know what area you are in, other members might be able to suggest who to take it to.

 

If it's not viable to repair, it might be worth listing it in the classifieds here for one of the tinkerers who like to restore these gems.  Then just keep an eye on the classifieds yourself to pick up a suitable replacement.

[surprisetech]

Oh, and welcome to Stereonet!

[Bermi]

31 minutes ago, surprisetech said:

The Nikko gear was pretty decent.  Well designed and well built.

The fault you describe could be something simple and worth getting repaired, but if the amplifier output stage has died, or there is another electronic fault that requires some time to diagnose, then it might not be cost effective.

 

Have you swapped the speakers & speaker cables to confirm that the amplifier is definitely the problem?

If so, then with power disconnected, firstly check the speaker wiring on the channel that is not working.  Make sure that the wires are all terminated properly at both ends and that there are no loose strands of wire that might have shorted to the other terminal.

Then check if one of the circuit breakers on the rear panel has activated.  If any have popped out, press it back in.  Reconnect power and test.

 

If that doesn't fix the problem, then the next step would be to clean the switches and controls, particularly the Volume control, speaker selection switches and the "Connect/Separate" switch on the rear panel.   That involves removing the cover and treating them with a contact cleaner spray (NOT WD-40), so should be done by someone competent in that area.

 

Beyond that, further fault finding would probably involve test equipment & a soldering iron and a suitably qualified technician.  If you let us know what area you are in, other members might be able to suggest who to take it to.

 

If it's not viable to repair, it might be worth listing it in the classifieds here for one of the tinkerers who like to restore these gems.  Then just keep an eye on the classifieds yourself to pick up a suitable replacement.

Thanks for that detail info Surprisetech.

I'll go and try your suggestions and get back to you later.

[Sub Sonic]

If the amplifier puts out sound on both channels in mono, then the fault is not in the speakers or output stage of the amplifier.

 

As mentioned above, I’d start with a clean of the switches and pots with Deoxit, and if no luck there, find a repairer. Chances are high that it can be repaired.

 

Cheers,

 

SS

[Bermi]

 

1 hour ago, Sub Sonic said:

If the amplifier puts out sound on both channels in mono, then the fault is not in the speakers or output stage of the amplifier.

 

As mentioned above, I’d start with a clean of the switches and pots with Deoxit, and if no luck there, find a repairer. Chances are high that it can be repaired.

 

Cheers,

 

SS

 

2 hours ago, surprisetech said:

The Nikko gear was pretty decent.  Well designed and well built.

The fault you describe could be something simple and worth getting repaired, but if the amplifier output stage has died, or there is another electronic fault that requires some time to diagnose, then it might not be cost effective.

 

Have you swapped the speakers & speaker cables to confirm that the amplifier is definitely the problem?

If so, then with power disconnected, firstly check the speaker wiring on the channel that is not working.  Make sure that the wires are all terminated properly at both ends and that there are no loose strands of wire that might have shorted to the other terminal.

Then check if one of the circuit breakers on the rear panel has activated.  If any have popped out, press it back in.  Reconnect power and test.

 

If that doesn't fix the problem, then the next step would be to clean the switches and controls, particularly the Volume control, speaker selection switches and the "Connect/Separate" switch on the rear panel.   That involves removing the cover and treating them with a contact cleaner spray (NOT WD-40), so should be done by someone competent in that area.

 

Beyond that, further fault finding would probably involve test equipment & a soldering iron and a suitably qualified technician.  If you let us know what area you are in, other members might be able to suggest who to take it to.

 

If it's not viable to repair, it might be worth listing it in the classifieds here for one of the tinkerers who like to restore these gems.  Then just keep an eye on the classifieds yourself to pick up a suitable replacement.

Thanks Sub Sonic and I tried all what you said Surprisedtech and no success. In desperation , I started jiggling the switches on the front of the Amp and when I pushed the '2CH/4CH Function' switch to the left, the right hand speaker started to work. When I took the pressure off the switch, the right hand side speaker stopped working again, hmmm.

Maybe just needs a clean???

Edited December 18, 2019 by Bermi

[Sub Sonic]

For sure, a clean with Deoxit is always the first port of call

 

Cheers,

 

SS

[Bermi]

28 minutes ago, Sub Sonic said:

For sure, a clean with Deoxit is always the first port of call

 

Cheers,

 

SS

 

Because this is all new to me, I would prefer someone competent to do it.

I live in Bermagui, Far South Coast, NSW. The closest large towns to me would be Narooma, Bega, Marimbula and Batemans Bay.

Not sure anyone around here can do it?

 

Good that it appears to be repairable, such a good HiFi unit. I mixed and matched the Amp with the Apan Turntable and Richard Allan Speakers at the RadioParts store in Nth Melbourne, Vic.

 

Edited December 18, 2019 by Bermi

[Bermi]

Or, I could take @surprisetech advice "...…… it might be worth listing it in the classifieds here for one of the tinkerers who like to restore these gems...…" At least I know it is going to a good home.

Actually, I'll be down sizing homes soon, so maybe selling the whole HiFi would be best, keeping it all together, hmmm. 

 

 

[surprisetech]

1 hour ago, Bermi said:

Thanks Sub Sonic and I tried all what you said Surprisedtech and no success. In desperation , I started jiggling the switches on the front of the Amp and when I pushed the '2CH/4CH Function' switch to the left, the right hand speaker started to work. When I took the pressure off the switch, the right hand side speaker stopped working again, hmmm.

Maybe just needs a clean???

That's good news.

Looking at the schematic, this should work as an interim fix.

Get a Stereo RCA cable (short one if you can).  Connect the white & red plugs on one end to the "2CH OUT" sockets, then connect the white & red plugs on the other end to the "4CH IN" sockets.  (White = LEFT & Red = RIGHT).

THEN, set the Function switch to the '4CH' position.

This will bypass the dodgy switch contact and won't alter normal operation.

Edited December 18, 2019 by surprisetech
left out a step

[Bermi]

3 hours ago, surprisetech said:

That's good news.

Looking at the schematic, this should work as an interim fix.

Get a Stereo RCA cable (short one if you can).  Connect the white & red plugs on one end to the "2CH OUT" sockets, then connect the white & red plugs on the other end to the "4CH IN" sockets.  (White = LEFT & Red = RIGHT).

THEN, set the Function switch to the '4CH' position.

This will bypass the dodgy switch contact and won't alter normal operation.

 

Ok. I had to google 'Stereo RCA Cable' and I think I may have some buried somewhere. I'll have a look, or buy one. I'll let you know how I went.

[Ratbob]

As a general rule for my old kit, every month or so I flick/rotate all the switches/knobs multiple times, even if it’s just stored. I’m thinking it keeps the contacts clean. 

[Bermi]

9 hours ago, Ratbob said:

As a general rule for my old kit, every month or so I flick/rotate all the switches/knobs multiple times, even if it’s just stored. I’m thinking it keeps the contacts clean. 

That makes sense, a good rule. My problem is that I haven't played the HiFi for a really long time, as in the lounge room the TV dominates, hmmm. Ideally I could have kept, and played, the HiFi in my art studio, in the garage, but living next to the coast would not be the ideal place for it.

[Bermi]

On 18/12/2019 at 1:51 PM, surprisetech said:

That's good news.

Looking at the schematic, this should work as an interim fix.

Get a Stereo RCA cable (short one if you can).  Connect the white & red plugs on one end to the "2CH OUT" sockets, then connect the white & red plugs on the other end to the "4CH IN" sockets.  (White = LEFT & Red = RIGHT).

THEN, set the Function switch to the '4CH' position.

This will bypass the dodgy switch contact and won't alter normal operation.

I found a white, red and yellow cable and connected the red and white plugs and did all as you recommended.

It didn't make any difference, BUT I jiggled the Function switch and now the right speakers are working in stereo. The switch is sensitive, but a little side nudge and the right speakers keeps works.

 

Now there is a new problem.

There is a crackling/distortion noise coming out of the speakers, regardless if a record is playing. I fiddled with all the front switches of the Amp and only when I pressed off the 'Speaker System Selector Switch' the noise stopped. When pressed on again, the noise came back. 

When I turned off the amp, the noise goes louder just before it stops. Any idea what is wrong?

 

The problem started yesterday, around the time I moved the Turntable's '33 - 45 Selector' switch to play a 45 single (which I haven't done for over a decade). The noise is still there during playing a 33 LP. I don't know if this is just a coincident to the noise?

[mbz]

I'm sure you see the connection between fiddling with switches and performance. It's a vintage amp, all switches need some magic spray as a minimum, enclosed switches may need deep cleaning ie, disassemble then clean especially function selector, tape monitor. So go to j-car(?) and buy a can of servisol "electrical clean and lube", maybe $12-, it is a cr@p product that does next to nothing but it's better than nothing (just). You could opt for the De-oxit also at j@ycar but you are forced to buy the gold which you don't need. I need to find better cleaning products...

[Bermi]

41 minutes ago, mbz said:

I'm sure you see the connection between fiddling with switches and performance. It's a vintage amp, all switches need some magic spray as a minimum, enclosed switches may need deep cleaning ie, disassemble then clean especially function selector, tape monitor. So go to j-car(?) and buy a can of servisol "electrical clean and lube", maybe $12-, it is a cr@p product that does next to nothing but it's better than nothing (just). You could opt for the De-oxit also at j@ycar but you are forced to buy the gold which you don't need. I need to find better cleaning products...

 

Thank you for your suggestion.

You are right, I see the connection. 

I located a Jaycar store only 1 hrs drive away. Since my Amp is 45 years old and never been cleaned, I think I better pay the extra money for the De0oxit Solution Kit $29.95 and do a proper job. 

I have never done this sort of thing before, but it doesn't sound too challenging to (unplug first) unscrew and open the Amp to give it a clean.

Since I will be selling the HiFi soon, it makes sense that I have it working properly.  

 

[Sub Sonic]

The Jaycar website doesn’t appear to have Deoxit spray, only the little Deoxit bottles with brushes In them.

The spray is best for cleaning switches and pots without disassembly, the little brush bottles can be used for open contacts such as RCA connections.

 

Altronics has Deoxit spray which is probably what you want.

 

Cheers,

 

SS

[Bermi]

2 hours ago, Sub Sonic said:

The Jaycar website doesn’t appear to have Deoxit spray, only the little Deoxit bottles with brushes In them.

The spray is best for cleaning switches and pots without disassembly, the little brush bottles can be used for open contacts such as RCA connections.

 

Altronics has Deoxit spray which is probably what you want.

 

Cheers,

 

SS

Ok, the spray is best.

Hmmm, the closet Altronics store is 6 hrs away (SYD), but looks like I can buy on line.

There are 3 Deoxit Spray Cans available:

https://www.altronics.com.au/search/all/?sr=Deoxit%2Bspray

F5 $44.95, D5 $42 and R44 $14.95

Will the low priced R44 do the job?

 

 

[surprisetech]

17 hours ago, Bermi said:

I found a white, red and yellow cable and connected the red and white plugs and did all as you recommended.

It didn't make any difference, BUT I jiggled the Function switch and now the right speakers are working in stereo. The switch is sensitive, but a little side nudge and the right speakers keeps works.

Sorry to hear.  That probably indicates that it's the common contact on that switch that is the problem.

Your plan to service all the switches with De-Oxit is certainly the next step.

[mbz]

54 minutes ago, Bermi said:

There are 3 Deoxit Spray Cans available:

https://www.altronics.com.au/search/all/?sr=Deoxit%2Bspray

F5 $44.95, D5 $42 and R44 $14.95

Will the low priced R44 do the job?

Sadly no... I vaguely recall that the preferred method is to use D5 for cleaning especially metal contact switches like speaker selectors. D5 can also be used on pots to clean the wiper however long term it may damage the resistance material so for pots use D5 then once clean followup with the lube F5.

 

I'd suggest getting the D5 only for the function selector

[Bermi]

20 minutes ago, mbz said:

Sadly no... I vaguely recall that the preferred method is to use D5 for cleaning especially metal contact switches like speaker selectors. D5 can also be used on pots to clean the wiper however long term it may damage the resistance material so for pots use D5 then once clean followup with the lube F5.

 

I'd suggest getting the D5 only for the function selector

Thanks for your help.

 

RE:.......D5 can also be used on pots to clean the wiper...….

Sorry for my ignorance, but I don't know what you mean?

[Bermi]

1 hour ago, surprisetech said:

Sorry to hear.  That probably indicates that it's the common contact on that switch that is the problem.

Your plan to service all the switches with De-Oxit is certainly the next step.

RE:.....…..to service all the switches with De-Oxit……….

Because the De-Oxit is a spray, can I just service the Amp's switches without dismantling it? 

Or do I have to remove the outer casing?

Edited December 20, 2019 by Bermi

[Bermi]

I found this very useful website to cleaning my amp. I think it's best to wait until after Christmas to buy the De-Oxit on line.

https://www.wikihow.com/Apply-Deoxit

 

Thanks for all your help, I'll let you know how it went.

[surprisetech]

On 20/12/2019 at 1:12 PM, Bermi said:

RE:.....…..to service all the switches with De-Oxit……….

Because the De-Oxit is a spray, can I just service the Amp's switches without dismantling it? 

Or do I have to remove the outer casing?

You do need to remove the cover to access the best point/s on the switches/pots to apply the spray.

The front of a switch or pot does not always have an opening, and there can often be a long shaft between the front panel control and the actual component.

[Bermi]

21 hours ago, surprisetech said:

You do need to remove the cover to access the best point/s on the switches/pots to apply the spray.

The front of a switch or pot does not always have an opening, and there can often be a long shaft between the front panel control and the actual component.

Thanks for the advice. A neighbour of mine gave me a can of 'CRC NF Contact Cleaner' so I'll try that soon.