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-   -   Trying to revive a Goodmans One Ten receiver (https://www.vintage-radio.net/forum/showthread.php?t=171539)

CrazySwede 30th Sep 2020 7:09 am

Trying to revive a Goodmans One Ten receiver
 
4 Attachment(s)
Hi there!
Just won this thing in an online auction here in Sweden for 10 euros.
Have so far just had time to do a quick look through. Lots of dust and some dead bugs, but under the crap it seems to be in pretty good physical shape. Very clean inside though (except for a dead bug jammed in the scale window. Poor thing).

After deciding that nothing looked scary under the hood I plugged it in and got a nice warm scale light but absolutely no sound in the speakers. Tried both A and B speaker connections and radio, aux and phono but just silence. Also worked the input buttons pretty good at no avail. So probably something is wrong electronically. Will start usual troubleshooting looking at fuses and clean contacts and controls. Have the service manuals so can check voltages.
But this being a piece of UK made gear I figured i would pop in here and se if any of you guys have any experience and input that could help me fix this beauty up. Thanks in advance!

David G4EBT 30th Sep 2020 8:53 am

Re: Trying to revive a Goodmans One Ten reciever
 
Welcome to the forum.

I don't recall having seen any Goodmans receivers mentioned on the forum, so can only suggest a few general checks you could carry out to try to narrow down in which sections of the receiver the fault(s) lie. Firstly, it's worth checking at the slider of the volume control (dual gang if stereo) with a signal tracer (or small amplifier) to see if you can hear any tuneable stations on the various wavebands. If so, that would mean that the RF, IF and detector stages are at least working.

As you get no audio to the speakers even when you input audio into the AUX and Phono sockets, it certainly seems like there is a fault/faults in the audio stages. Sometimes such equipment doesn't take kindly to being switched on with no speakers connected or mismatched non-original speakers, causing damaged to the output transistors/ICs.

As you have the manual, as you will know, a good place to start would be voltage checks, but if you're in luck and the RF/IF/Detector stages are indeed working, you could use a signal tracer to follow the audio signal through each stage of the audio section to try to pinpoint the fault.

Hope that might help a bit.

Good luck with it.

chriswood1900 30th Sep 2020 9:43 am

Re: Trying to revive a Goodmans One Ten reciever
 
Welcome to the forum.
The Goodmans 110 was a reasonable effort at producing a modern looking receiver. I owned one for a while and was pleased with its performance.
It has appeared before on the forum where part way down are links to the manuals. https://www.vintage-radio.net/forum/...ad.php?t=46056
Standard repair techniques should work, although it is mainly one large circuit board it is in sections. Check power supplies are present and see if you can hear anything at the tape outputs from the tuner or can produce any sound from the inputs. Don't rule out badly corroded switches and din plugs needing a good clean.
Good Luck

jjl 30th Sep 2020 10:43 am

Re: Trying to revive a Goodmans One Ten reciever
 
If the scale lamps PL2, 3, and 4 are lit, at least the mains fuse is intact. I can't find where these lamps take power from in the service manual, but given that they are 12V types they are probably powered from the +14.3V or -14.3V rail. In which case these supplies must be present.
I'd check the fuses in the +35V and -35V rails to the power amplifiers. Don't be tempted to just replace these if they are blown as they will have failed for a reason - most likely failure of output transistors for either power supply variant or rectifier diodes or smoothing capacitors for the earlier variant.

John

CrazySwede 30th Sep 2020 11:04 am

Re: Trying to revive a Goodmans One Ten reciever
 
2 Attachment(s)
Thanks for responding, guys!
How do I figure out if I have an early or later model?

Have some more pics of the internals here if it may give some clues?

jimmc101 30th Sep 2020 12:25 pm

Re: Trying to revive a Goodmans One Ten reciever
 
The four fuses on the bracket from the mains transformer suggest that yours is a later model. (See the manual I posted in the link above, pt1 page 6 and pt2 page 2).

Good luck with it.

Jim

jjl 30th Sep 2020 12:37 pm

Re: Trying to revive a Goodmans One Ten reciever
 
I see now that the scale lamps are powered from the 12V A.C. available between the 30V and 18V taps on the secondary of the mains transformer. This means that F6 on the later power supply circuit must be intact, but any of the +/- 13.4V and +/- 35V rails may be absent.

John

CrazySwede 30th Sep 2020 6:42 pm

Re: Trying to revive a Goodmans One Ten reciever
 
1 Attachment(s)
A little progress!
Measured continuity over all fuses and the two 18v where open. Fuses were OK but the holders very oxidized. Cleaned them, popped the fuses back and turned it on and we have sound!

...but only static and a lot of popping. Now on to a thorough cleaning of the buttons and potentiometers.

vinrads 30th Sep 2020 7:28 pm

Re: Trying to revive a Goodmans One Ten reciever
 
That sounds promising a good clean of all the controls and switches should have it working , Mick.

Reelman 30th Sep 2020 8:55 pm

Re: Trying to revive a Goodmans One Ten receiver
 
Glad to hear you are making progress. When it is finally up and running there are a couple of points to be aware of: there will be a thump from the speakers when turning on, this is normal if unpleasant. However in the 20+ years I used mine it never damaged the speakers that were connected for the same Length of time. If you don’t like it then switch on to headphones first and then immediately to speakers. The volume control will be noisy by this time and because of a tapping on the track very difficult to find a replacement.

Other than the above mine never had a fault of any description.....

Peter

CrazySwede 1st Oct 2020 7:49 am

Re: Trying to revive a Goodmans One Ten receiver
 
Thanks for input, Peter.
Yup, that thump when powering up had me jumping. Good to read that it is a standard feature :-).

CrazySwede 2nd Oct 2020 2:57 pm

Re: Trying to revive a Goodmans One Ten receiver
 
2 Attachment(s)
Hmm, this puppy may be worse off than I first thought. A good deoxit clean of all breakers and controls have not helped at all.

Some symptoms so far:
- When I turn it on I get a solid thump in both speakers (happens booth on speaker1 and 2)
- I get no audio from AUX or Phono inputs
- Sometime I can get a loud static kind of loud screeching noise when activate L,M or K radio bands.
- When swithing input I get loud pops in the speakers
- When I get the loud noise described above this happens even if volume button is turned off completely.
- No audio in headphones either.

Going to move on now to check voltages.
One question: could the above described behaviour be a sign of that I still have problems with bad contact in the fuse holders that I described above?
On of them have been hard to get to so not sure if I have managed to clean off the corrosion.

Reelman 4th Oct 2020 11:39 am

Re: Trying to revive a Goodmans One Ten receiver
 
One additional problem you need to be aware of is that I think this uses “lockfit” transistors which are known to be unreliable and should be replaced by non-lockfit types. A search of the forum will produce suggested types.
You could try some signal injection directly to the PCB to try and isolate the faulty stage or stages.
Peter

stevehertz 4th Oct 2020 11:50 am

Re: Trying to revive a Goodmans One Ten receiver
 
1 Attachment(s)
There were quite a few Goodmans receivers in different guises, some with built in record decks. The three main (serious!) ones were the Module 90, 'One Ten', and the '150'. I started my hifi career with a Module 90 in 1976 (long gone) and I now have a 150 in my collection of vintage receivers. I am in the process of buying a One Ten from a friend. All models have been featured on here at various times. Out of interest, here's a photo of my restored 150. BTW, I would clean those switches again and with the power off operate them many times. You'd be surprised at how dirty and unresponsive to cleaning they can be sometimes. Best of luck.

Edit. Out of interest, I read or was told in the 70s that a rich Arab Sheikh had bought - I think it was thirty - Goodmans 150s and specified that they were all gold plated. What bits were gold plated I don't know, but anyway, it's a good and somewhat plausible story. I see no reason for someone to make up something so obscure.

david freeman 6th Oct 2020 7:56 pm

Re: Trying to revive a Goodmans One Ten receiver
 
The 150 is a superb sounding receiver.
It was the most powerful British made receiver when introducing in 1975.
Had excellent reviews in the HiFi press.

CrazySwede 6th Oct 2020 8:42 pm

Re: Trying to revive a Goodmans One Ten receiver
 
Thanks for input!
Have hit the pots and switches with another round of contact cleaning spray (ran out so need to get more) and replaced all fuses. They measured ok but just to be sure they're ok.
But still: only lights and no audio except for a thump on power up and some pops when hitting the switches.
Otherwise same symptoms as I described in an earlier post.
Will get another can of contact cleaner and give it one more try. But if third time is no charm with that method, I need some help to troubleshoot further. I have a multimeter and know the basics about measuring voltages and currents and continuity.
Is there by way to measure if a switch is bad? Any other possible causes that makes this thing quiet?

CrazySwede 7th Oct 2020 7:17 pm

Re: Trying to revive a Goodmans One Ten receiver
 
By the way, would it be possible to pop the buttons off the switches to get better access for the contact cleaning spray from the front side?
Some of them are hard to reach from inside (caps and stuff in the way of the hole in the back of the switches).
But don't want to break anything either...

jamesperrett 7th Oct 2020 10:56 pm

Re: Trying to revive a Goodmans One Ten receiver
 
Sounds like a problem with the preamplifier stages. If it affects both channels I'd look at the power supply first (which appears to be the supply associated with the fuses that you mention earlier). The diagram you posted shows the expected voltages at various points in the circuit so I'd start by checking with your meter that those voltages are as expected.

CrazySwede 8th Oct 2020 8:52 am

Re: Trying to revive a Goodmans One Ten receiver
 
4 Attachment(s)
Thanks for that advice, James!

I have started trying to measure voltages and so far I think they check out. This is the outgoing DC:s after the psu at points 13, 24, 25. But after that I have trouble interpreting the schematics and finding the right points to measure imortant voltages (no markings on the board).
Here´s where my inexperience starts to show :shrug:...

So if someone with more experince could take a peek at the schematics and give me a pointer where the important measure points in the different areas can be found I would very much appreciate it.:thumbsup:

If you tell me at which components to measure I should be able to locate using the layout sheet.

I have attached the servicemanual and the schematics. Also stitch the pages together to make it easier to read.

EDIT: noticed that the forum tool compressed the jpg-images so they may be hard to read. Here´s a shared G-drive folder with the originals.
https://drive.google.com/drive/folde...fX?usp=sharing



But I will also defenitely have to get more contact cleaner and have another go at the switches. Last night while trying more I found at some points/combination of switch presses I got some consistant noise and also a weak audio from the AUX which I had connected to a music source.

jamesperrett 9th Oct 2020 12:02 am

Re: Trying to revive a Goodmans One Ten receiver
 
My next suggestion would be to check the voltage on pins 14 and 7 of IC2 and IC3. Have you tried feeding a signal into the tape socket with the tape monitor switch engaged?


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