UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Audio (record players, hi-fi etc)

Notices

Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment.

Closed Thread
 
Thread Tools
Old 20th Sep 2023, 5:48 pm   #1
Nickaliath
Tetrode
 
Join Date: Aug 2022
Location: Somerset, UK.
Posts: 62
Default NAD 3020A No sound after changing capacitors.

Hello all,

I have just re-capped a NAD 3020A. It is now decided not to have any sound coming out of it. The red power light illuminates, But that's it.

I am planning to go over all the solder joints tonight, To make sure they are all ok.

Now I changed all the capacitors for the correct replacement, But I want to make sure I haven't made a mistake along the way.

The 3020A circuit diagram is nowhere to be found online.
I wanted to double check all the capacitor values, So I can make sure they have all been fitted in the correct location.

I did try a couple other NAD service manual, But they don't seem to tie up together with this board.

I don't suppose anyone has one or a diagram of the board with capacitor values?

Thanks
Nickaliath is offline  
Old 20th Sep 2023, 6:11 pm   #2
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,286
Default Re: "NAD 3020A No sound after changing capacitors." by Nickaliath - reported by Stati

An all too familiar story. "I changed ALL the capacitors and now it don't work".

What made you decide to change the capacitors? Did they test faulty? Did you take pictures and make notes?

All water under the bridge now. Check your work and rectify any errors. Are the replacement caps of the right value and fitted the right way round?

If that doesn't work it's time to get your meter out, firstly checking that all power supply voltages are present and correct.

-----

I have a NAD3020 and after 40 years it's starting to hum like a Dansette. When I get a round tuit I'll change the smoothing capacitors and leave everything else well alone.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now  
Old 20th Sep 2023, 6:20 pm   #3
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,995
Default Re: NAD 3020A No sound after changing capacitors.

Did it work before your recapping-misadventure?

When doing this sort of thing I tend to replace parts one at a time and then check it still works after each part-replacement. OK it adds extra time to the process but does at least make things easier to fault-find when something goes wrong.
__________________
I'm the Operator of my Pocket Calculator. -Kraftwerk.
G6Tanuki is offline  
Old 20th Sep 2023, 6:31 pm   #4
Beobloke
Heptode
 
Join Date: Oct 2007
Location: Southampton, Hampshire, UK.
Posts: 821
Default Re: NAD 3020A No sound after changing capacitors.

Did you happen to remove the pre/power links before you started work on it?

If so, did you remember to re-fit them?
Beobloke is offline  
Old 20th Sep 2023, 6:40 pm   #5
60 oldjohn
Dekatron
 
Join Date: Dec 2004
Location: East Yorkshire, UK.
Posts: 3,985
Default Re: NAD 3020A No sound after changing capacitors.

I cut the old component out leaving a short length of wire, that can be trimmed later and test for progress after each component change. Best keep only the current component on the bench if you need to check the value. This was after I got one wire from a capacitor on the adjacent solder tag, robbing me of a raster on a TV. Lucky I had checked after each replacement. This was before the luxury of instant digital photography.

John.
__________________
My favourite text message "I'll be there in five minutes, if not read again"
60 oldjohn is offline  
Old 20th Sep 2023, 7:08 pm   #6
Nickaliath
Tetrode
 
Join Date: Aug 2022
Location: Somerset, UK.
Posts: 62
Default Re: "NAD 3020A No sound after changing capacitors." by Nickaliath - reported by Stati

Yeah, I completely agree.

I previously did a cap change on the same type amp, With no issues at all.

Someone I know asked me to take a look at it and sort the sound issue. This was all down to dirty controls and rectified. So it was all working.
However, He asked to do a cap change to make it last longer for the future.

When he hadn't used it for a while, It would take a while till the red light turned on. Which I presume is a cap issue powering up?

I checked all the joints on the solder points and re-flowed them.

I also checked the correct orientation, Corresponding with the board markings.
It appears they all face the same way according to the board.

Sound is coming out, But very quietly.



Quote:
Originally Posted by Station X View Post
An all too familiar story. "I changed ALL the capacitors and now it don't work".

What made you decide to change the capacitors? Did they test faulty? Did you take pictures and make notes?

All water under the bridge now. Check your work and rectify any errors. Are the replacement caps of the right value and fitted the right way round?

If that doesn't work it's time to get your meter out, firstly checking that all power supply voltages are present and correct.

-----

I have a NAD3020 and after 40 years it's starting to hum like a Dansette. When I get a round tuit I'll change the smoothing capacitors and leave everything else well alone.
Nickaliath is offline  
Old 20th Sep 2023, 7:10 pm   #7
Nickaliath
Tetrode
 
Join Date: Aug 2022
Location: Somerset, UK.
Posts: 62
Default Re: NAD 3020A No sound after changing capacitors.

Quote:
Originally Posted by G6Tanuki View Post
Did it work before your recapping-misadventure?

When doing this sort of thing I tend to replace parts one at a time and then check it still works after each part-replacement. OK it adds extra time to the process but does at least make things easier to fault-find when something goes wrong.
Yes, I did exactly that. 1 at a time. I always do it this way.

But I now think I have put one in of an incorrect value, By mistake.

I stupidly didn't make a note as I was removing, Which I now regret.

Wouldn't be so bad if I could find the diagram for the circuit board.
Nickaliath is offline  
Old 20th Sep 2023, 7:11 pm   #8
Nickaliath
Tetrode
 
Join Date: Aug 2022
Location: Somerset, UK.
Posts: 62
Default Re: NAD 3020A No sound after changing capacitors.

Quote:
Originally Posted by Beobloke View Post
Did you happen to remove the pre/power links before you started work on it?

If so, did you remember to re-fit them?
Yes, I did. But I put them back in.
Nickaliath is offline  
Old 20th Sep 2023, 7:14 pm   #9
Nickaliath
Tetrode
 
Join Date: Aug 2022
Location: Somerset, UK.
Posts: 62
Default Re: NAD 3020A No sound after changing capacitors.

Edit: Its a NAD 3020 series 20. Not 3020A
Nickaliath is offline  
Old 20th Sep 2023, 7:35 pm   #10
Beobloke
Heptode
 
Join Date: Oct 2007
Location: Southampton, Hampshire, UK.
Posts: 821
Default Re: NAD 3020A No sound after changing capacitors.

Quote:
Originally Posted by Nickaliath View Post
Yes, I did. But I put them back in.
No worries - just thought I’d double check. We’ve all done it!

Haven’t we….?
Beobloke is offline  
Old 20th Sep 2023, 7:50 pm   #11
Edward Huggins
Dekatron
 
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 8,326
Default Re: NAD 3020A No sound after changing capacitors.

"He asked me to do a cap change" - what kind of nonsense is this? "To make it last longer" - more nonsense. Why be influenced by an Amateur's opinion? In future use your own judgement and carry out the re-working as you see fit. Now, in spite of your best intentions, you could be a long while sorting this.....
__________________
Edward.
Edward Huggins is offline  
Old 20th Sep 2023, 7:57 pm   #12
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,932
Default Re: NAD 3020A No sound after changing capacitors.

As we all know, there is a widespread belief in the HiFi world that equipment needs to be comprehensively recapped every decade or so to maintain the sound quality. If you're doing work for customers then you have to do what they want, no matter how bonkers it is.
paulsherwin is online now  
Old 20th Sep 2023, 7:59 pm   #13
ben
Dekatron
 
ben's Avatar
 
Join Date: Aug 2006
Location: Madrid, Spain / Wirral, UK
Posts: 7,498
Default Re: NAD 3020A No sound after changing capacitors.

Unfortunately, there is a whole lot of this capacitor nonsense spouted online, by people with little or no electronics knowledge. They think it's like a car where you have to change the oil every so often or something.

In this case the OP says there is audio but quiet, so I would be injecting a signal at various points to see where the audio is getting cut. And to see if the output stage is at least capable of any oomph.
__________________
Regards,
Ben.
ben is offline  
Old 20th Sep 2023, 8:04 pm   #14
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,932
Default Re: NAD 3020A No sound after changing capacitors.

Personally I suspect this is a switchgear problem and nothing to do with recapping. The 3020 switchgear isn't exactly broadcast quality. It should be easy enough to determine where the signal is getting lost.

Are both channels equally affected?
paulsherwin is online now  
Old 20th Sep 2023, 8:06 pm   #15
jamesperrett
Octode
 
Join Date: May 2007
Location: Liss, Hampshire, UK.
Posts: 1,873
Default Re: NAD 3020A No sound after changing capacitors.

Quote:
Originally Posted by ben View Post
Unfortunately, there is a whole lot of this capacitor nonsense spouted online, by people with little or no electronics knowledge.
Sadly this myth is also perpetuated by certain manufacturers nowadays.

Since there is some faint audio getting through I would check the tape monitor switch and also try a buzz test on the power amp inputs.
jamesperrett is offline  
Old 20th Sep 2023, 8:06 pm   #16
Goldie99
Heptode
 
Join Date: Jul 2014
Location: Boston, Lincolnshire, UK.
Posts: 995
Default Re: NAD 3020A No sound after changing capacitors.

Not sure which circuit this one is, but the headphones socket is a good candidate if it's both channels.
Goldie99 is offline  
Old 20th Sep 2023, 9:13 pm   #17
DMcMahon
Dekatron
 
DMcMahon's Avatar
 
Join Date: Apr 2019
Location: Worthing, West Sussex, UK.
Posts: 6,600
Default Re: NAD 3020A No sound after changing capacitors.

hifiengine.com has various manuals and schematics for the various NAD 3020 models, including schematic for the basic 3020, this does show component values.

David
DMcMahon is offline  
Old 20th Sep 2023, 9:47 pm   #18
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,286
Default Re: NAD 3020A No sound after changing capacitors.

One post moved to a new thread here:-

https://www.vintage-radio.net/forum/...d.php?t=204126
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now  
Old 20th Sep 2023, 9:49 pm   #19
Richardgr
Heptode
 
Join Date: Oct 2019
Location: Täby, Sweden
Posts: 702
Default Re: NAD 3020A No sound after changing capacitors.

A lot of headshaking over replacing 20 year old electrolytics. Possibly they were 5000 hour rated parts, well beyond their allotted lifespans.

Many years ago I bought a lot of white goods all together, and on queue, at 10 years old, they all packed up one after another. It is reasonable after a certain time period to replaced stressed parts rather than fix issues in an expensive piecemeal way.
Richardgr is offline  
Old 20th Sep 2023, 9:59 pm   #20
ben
Dekatron
 
ben's Avatar
 
Join Date: Aug 2006
Location: Madrid, Spain / Wirral, UK
Posts: 7,498
Default Re: NAD 3020A No sound after changing capacitors.

Quote:
Originally Posted by Richardgr View Post
A lot of headshaking over replacing 20 year old electrolytics. Possibly they were 5000 hour rated parts, well beyond their allotted lifespans..
Why stop there? Don't forget those 20 year old diodes, resistors, transistors, pots, wire, transformer...

Seriously, I'm all for replacing parts that have drifted in value or otherwise faulty, but blanket changing of parts willy-nilly is absurd, and in this case is what led to the OP's problem. Proper troubleshooting, not a shotgun approach, is what is sadly lacking.
__________________
Regards,
Ben.
ben is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 5:18 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.