Beloved Tandberg Series 15 - Page 5 - UK Vintage Radio Repair and Restoration Discussion Forum

af024 · 13th Aug 2009, 9:03 pm

Here we are guys - some photos of a working switch.

If you separate the slider part from the contacts, it looks like the contacts can probably fall out. Interestingly there are multiple places where you can fit them back! Worst still, you can get the sides mixed up (they are not symmetrical).

Anyhow, maybe these two shots help.

Regards,

Andy

Paulus.d · 14th Aug 2009, 2:52 pm

Thanks for the nice clear pics!
As my PCBS are out of the machine I had a close look - mine are the same as those.
I did think for a minute that one of the funky top hat contacts had gone but no.....

I've spent some time away for a bit and now I'm back! Both PCB's have had 100% caps changed and we're ready for testing - stay tuned for the next episode!!!!

Paulus.d

PS Ilikevalvesme: I've not heard from you yet, about the spares!!!!

Paulus.d · 15th Aug 2009, 12:52 pm

Back again - still no better, the origonal problem is still here.

I can now seriously say I don't know what to do next...
Ilikevalvesme has offered some spare PCB's and other parts for this so I need those now to swap the boards over.

Regards Paul

The General · 15th Aug 2009, 1:58 pm

Paul,
You have a PM.
Sorry for the delay, we have been busy every evening this week preparing my wife's essay & video for her study course. Submitted yesterday, so back up to full speed now!
Cheers,
Mark.

flyingtech55 · 15th Aug 2009, 9:07 pm

Paul

Which bit of 'renew the record/playback switch' didn't you understand. Some folk say 'renew the capacitors' as a kind of universal sinecure. Motorboating is very common result of worn/defective record/playback switches in tape recorders. You've already been told this by someone who has much practical experience of Tandberg equipment.

TimR

Nickthedentist · 16th Aug 2009, 10:05 am

Can you actually get replacements, thought, Tim?

flyingtech55 · 16th Aug 2009, 9:08 pm

Hi Nick

Good and valid comment!...I would expect nothing less from you! However, whether you can get the parts or not is a mute point. If the part is defective then it makes no difference. There is no point renewing other good parts if the actual fault is caused by another part whether it is available or not.

I still have some contacts within Tandberg with whom I have a long and happy association. I'll give them a 'ring' tomorrow and ask them about parts availability. Can anyone provide me with a model number of the machine and circuit reference for the switch?

TimR

Paulus.d · 17th Aug 2009, 5:39 pm

OK - if I hard wire the connections to the REC-PLAY-AMP switch so that it's stuck in PLAY then test it again. If the problem persists then it's not the switch, agreed?

I Have checked this switch again and again - I would have loved it to be the cause of this but I've powered it up and moved and pushed the contacts on the switch waiting for it to show some signs of the problem stopping but it doesn't. Unless a track on the PCB that feeds this switch is cracked!!!!!

Regards
Paul

Kat Manton · 17th Aug 2009, 6:11 pm

Hi,

I've had my share of fun and games with the 'AMP/PB/REC' switch in these. There's quite a bit of 'give' in the mechanism. What seems to happen is that the lever may be in the 'PB' position but the switch contacts aren't. This connects bits of circuitry which aren't supposed to be connected, causing weird faults.

One machine I had could be persuaded to work by gently approaching 'PB' from 'AMP' - this left the contacts in the correct positions. Flicking the lever caused the contacts to move slightly too far.

It's going back a while but I seem to remember curing one by strategic placement of a rubber band and another by very carefully bending the arms which support the little contact pads.

If you remove the contacts entirely and hard-wire the switch connections for 'PB' this will, indeed, prove once and for all whether the switch is to blame. If it is, you may find the cause is as I found. Reassemble it and examine closely which contacts are connected in the 'PB' position and make sure they're only the ones that are supposed to be connected.

I hope that helps.

Cheers, Kat

Paulus.d · 17th Aug 2009, 8:03 pm

Welcome on board the thread, Kat.

I've just put the machine on and did what you just said - I switched on, turned the volume slowly up, the light begins to dim, a humming builds up and on full goes B-B-B. turning it down a little just humming, I pushed the level slowly into AMP, until click light comes up to full brightness and the hum is replaced by a light hiss. Sliding back down, as you slowly come down the light dims and the humming starts. The process in REC is the same humming into a quiet hiss then back to humming. The slider has some issues because it's is slightly noisy when you move it.

As it stands at the moment, I have a couple of spare PCB's, a new meter and the mains transformer heading my way from 'ilikevalvesme' and so will swap the PRE-AMP PCB over. I really don't want to hard wire it to PLAY mode.
***NEW INFORMATION**
**The humming and B-B-B sound decreases a lot when the treble control is backed off**

I suppose it must be possible it has some other component damaged that can't be found without proper meters and tools...

Regards & many thanks to all who have help in this pesky repair job....you know who you are!!!!

Regards Paul
PS I bet the MODS will be pleased when this thing gets fixed..... or not

LOL

Paulus.d · 21st Aug 2009, 10:20 am

PCB's arrived now so not long to wait!!!!!

Paulus.d · 21st Aug 2009, 2:56 pm

the on-going Tandberg story:-

Pre-amp Board is now swapped. Fault still exists - fault NOT the sliding switch
Power amp is now swapped, including minor re-wiring as this one seems to have the regulator on the board. Fault still exists, but is louder in playback volume.

Transformer swapped - mine had a voltage output of 23. volts, this one's 32v - no dimming light but as you increase the volume at a certain point,the volume backs off, but it is improved.

Conclusions

It's still not working 100%, both PCB's have been changed, the transformer has been changed and the power amp board has replaced the old rectifier. I am now thinking the volume control replacement is next as it links the Pre & power amp boards together through it.

Best regards Paul

Steve_P · 21st Aug 2009, 3:15 pm

Have you tested the recorder the panels came out of? There's very little else this can be after the volume control. Make sure the earths are OK and clean that new switch - several times.

You may have swapped a duff switch for a duff switch.

Cheers,

Steve P.

Paulus.d · 21st Aug 2009, 3:31 pm

I suppose it's possible!!!!!
the boards came from a member 'ilikevalvesme' who offered them as spares plus a mter and transformer. I would have thought the switch would be OK.

By the way how;s the trio tape deck?

Regards Paul

Steve_P · 21st Aug 2009, 3:37 pm

Sat here waiting it's turn.

This Tandberg's getting stupid now isn't it...

Cheers,

Steve P.

Paulus.d · 21st Aug 2009, 3:50 pm

Yep - if I can't do it soon, I'm gonna strip it, and possibly use an amp from one of my Elizabethans!!!!!!!

Paul

Steve_P · 21st Aug 2009, 3:52 pm

Don't you dare. We've come this far...

Cheers,

Steve P.

Paulus.d · 21st Aug 2009, 3:56 pm

Right I've got the thing sitting on a chair ( no table space here y'know) and I switched it on, same as before problem etc until I touched the track switch assembly - I pulled a wire to get to the dc volts cnnection on the pre amp pcb and bang - fault disappeared full volume - ****** loud - - - IT'S IN THE TRACK SWITCH ASSEMBLY!!!!!!!!!!!

Paul

Steve_P · 21st Aug 2009, 4:14 pm

At last. Now you can fix it.

Cheers,

Steve P.

Nickthedentist · 21st Aug 2009, 4:27 pm

At long last!!!! You win the prize for one of the longest repair threads I've seen here (the other was mcourtman's humming Murphy record player thread, ISTR).

Well done

Probably best to put back the original components, as they will have been matched to each other and to the heads etc.

Enjoy the weekend,

Nick.

13th Aug 2009, 9:03 pm	#81
af024 Octode Join Date: Jan 2003 Location: Ashby-de-la-Zouch (it's not by the sea) Posts: 1,255	Re: Beloved Tandberg Series 15 Here we are guys - some photos of a working switch. If you separate the slider part from the contacts, it looks like the contacts can probably fall out. Interestingly there are multiple places where you can fit them back! Worst still, you can get the sides mixed up (they are not symmetrical). Anyhow, maybe these two shots help. Regards, Andy Attached Thumbnails __________________ Now where on earth did I remove that from?

14th Aug 2009, 2:52 pm	#82
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Beloved Tandberg Series 15 Thanks for the nice clear pics! As my PCBS are out of the machine I had a close look - mine are the same as those. I did think for a minute that one of the funky top hat contacts had gone but no..... I've spent some time away for a bit and now I'm back! Both PCB's have had 100% caps changed and we're ready for testing - stay tuned for the next episode!!!! Paulus.d PS Ilikevalvesme: I've not heard from you yet, about the spares!!!!

15th Aug 2009, 12:52 pm	#83
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Beloved Tandberg Series 15 Back again - still no better, the origonal problem is still here. I can now seriously say I don't know what to do next... Ilikevalvesme has offered some spare PCB's and other parts for this so I need those now to swap the boards over. Regards Paul

15th Aug 2009, 1:58 pm	#84
The General Hexode Join Date: Apr 2007 Location: Milton Keynes, Buckinghamshire, UK. Posts: 329	Re: Beloved Tandberg Series 15 Paul, You have a PM. Sorry for the delay, we have been busy every evening this week preparing my wife's essay & video for her study course. Submitted yesterday, so back up to full speed now! Cheers, Mark.

15th Aug 2009, 9:07 pm	#85
flyingtech55 Octode Join Date: Nov 2005 Location: Ayrshire, UK. Posts: 1,096	Re: Beloved Tandberg Series 15 Paul Which bit of 'renew the record/playback switch' didn't you understand. Some folk say 'renew the capacitors' as a kind of universal sinecure. Motorboating is very common result of worn/defective record/playback switches in tape recorders. You've already been told this by someone who has much practical experience of Tandberg equipment. TimR __________________ All those moments will be lost in time, like tears in rain.

16th Aug 2009, 10:05 am	#86
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,844	Re: Beloved Tandberg Series 15 Can you actually get replacements, thought, Tim?

16th Aug 2009, 9:08 pm	#87
flyingtech55 Octode Join Date: Nov 2005 Location: Ayrshire, UK. Posts: 1,096	Re: Beloved Tandberg Series 15 Hi Nick Good and valid comment!...I would expect nothing less from you! However, whether you can get the parts or not is a mute point. If the part is defective then it makes no difference. There is no point renewing other good parts if the actual fault is caused by another part whether it is available or not. I still have some contacts within Tandberg with whom I have a long and happy association. I'll give them a 'ring' tomorrow and ask them about parts availability. Can anyone provide me with a model number of the machine and circuit reference for the switch? TimR __________________ All those moments will be lost in time, like tears in rain. Last edited by flyingtech55; 16th Aug 2009 at 9:11 pm. Reason: Sloppy sentence construction.

17th Aug 2009, 5:39 pm	#88
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Beloved Tandberg Series 15 OK - if I hard wire the connections to the REC-PLAY-AMP switch so that it's stuck in PLAY then test it again. If the problem persists then it's not the switch, agreed? I Have checked this switch again and again - I would have loved it to be the cause of this but I've powered it up and moved and pushed the contacts on the switch waiting for it to show some signs of the problem stopping but it doesn't. Unless a track on the PCB that feeds this switch is cracked!!!!! Regards Paul

17th Aug 2009, 6:11 pm	#89
Kat Manton Retired Dormant Member Join Date: Jul 2005 Location: West Yorkshire, UK. Posts: 1,700	Re: Beloved Tandberg Series 15 Hi, I've had my share of fun and games with the 'AMP/PB/REC' switch in these. There's quite a bit of 'give' in the mechanism. What seems to happen is that the lever may be in the 'PB' position but the switch contacts aren't. This connects bits of circuitry which aren't supposed to be connected, causing weird faults. One machine I had could be persuaded to work by gently approaching 'PB' from 'AMP' - this left the contacts in the correct positions. Flicking the lever caused the contacts to move slightly too far. It's going back a while but I seem to remember curing one by strategic placement of a rubber band and another by very carefully bending the arms which support the little contact pads. If you remove the contacts entirely and hard-wire the switch connections for 'PB' this will, indeed, prove once and for all whether the switch is to blame. If it is, you may find the cause is as I found. Reassemble it and examine closely which contacts are connected in the 'PB' position and make sure they're only the ones that are supposed to be connected. I hope that helps. Cheers, Kat

17th Aug 2009, 8:03 pm	#90
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Beloved Tandberg Series 15 Welcome on board the thread, Kat. I've just put the machine on and did what you just said - I switched on, turned the volume slowly up, the light begins to dim, a humming builds up and on full goes B-B-B. turning it down a little just humming, I pushed the level slowly into AMP, until click light comes up to full brightness and the hum is replaced by a light hiss. Sliding back down, as you slowly come down the light dims and the humming starts. The process in REC is the same humming into a quiet hiss then back to humming. The slider has some issues because it's is slightly noisy when you move it. As it stands at the moment, I have a couple of spare PCB's, a new meter and the mains transformer heading my way from 'ilikevalvesme' and so will swap the PRE-AMP PCB over. I really don't want to hard wire it to PLAY mode. *NEW INFORMATION The humming and B-B-B sound decreases a lot when the treble control is backed off I suppose it must be possible it has some other component damaged that can't be found without proper meters and tools... Regards & many thanks to all who have help in this pesky repair job....you know who you are!!!! Regards Paul PS I bet the MODS will be pleased when this thing gets fixed..... or not LOL

21st Aug 2009, 10:20 am	#91
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Beloved Tandberg Series 15 PCB's arrived now so not long to wait!!!!!

21st Aug 2009, 2:56 pm	#92
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Beloved Tandberg Series 15 the on-going Tandberg story:- Pre-amp Board is now swapped. Fault still exists - fault NOT the sliding switch Power amp is now swapped, including minor re-wiring as this one seems to have the regulator on the board. Fault still exists, but is louder in playback volume. Transformer swapped - mine had a voltage output of 23. volts, this one's 32v - no dimming light but as you increase the volume at a certain point,the volume backs off, but it is improved. Conclusions It's still not working 100%, both PCB's have been changed, the transformer has been changed and the power amp board has replaced the old rectifier. I am now thinking the volume control replacement is next as it links the Pre & power amp boards together through it. Best regards Paul

21st Aug 2009, 3:15 pm	#93
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Beloved Tandberg Series 15 Have you tested the recorder the panels came out of? There's very little else this can be after the volume control. Make sure the earths are OK and clean that new switch - several times. You may have swapped a duff switch for a duff switch. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

21st Aug 2009, 3:31 pm	#94
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Beloved Tandberg Series 15 I suppose it's possible!!!!! the boards came from a member 'ilikevalvesme' who offered them as spares plus a mter and transformer. I would have thought the switch would be OK. By the way how;s the trio tape deck? Regards Paul

21st Aug 2009, 3:37 pm	#95
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Beloved Tandberg Series 15 Sat here waiting it's turn. This Tandberg's getting stupid now isn't it... Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

21st Aug 2009, 3:50 pm	#96
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Beloved Tandberg Series 15 Yep - if I can't do it soon, I'm gonna strip it, and possibly use an amp from one of my Elizabethans!!!!!!! Paul

21st Aug 2009, 3:52 pm	#97
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Beloved Tandberg Series 15 Don't you dare. We've come this far... Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

21st Aug 2009, 3:56 pm	#98
Paulus.d Hexode Join Date: Mar 2008 Location: Margate, Kent, UK. Posts: 355	Re: Beloved Tandberg Series 15 Right I've got the thing sitting on a chair ( no table space here y'know) and I switched it on, same as before problem etc until I touched the track switch assembly - I pulled a wire to get to the dc volts cnnection on the pre amp pcb and bang - fault disappeared full volume - ****** loud - - - IT'S IN THE TRACK SWITCH ASSEMBLY!!!!!!!!!!! Paul

21st Aug 2009, 4:14 pm	#99
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Beloved Tandberg Series 15 At last. Now you can fix it. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

21st Aug 2009, 4:27 pm	#100
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,844	Re: Beloved Tandberg Series 15 At long last!!!! You win the prize for one of the longest repair threads I've seen here (the other was mcourtman's humming Murphy record player thread, ISTR). Well done Probably best to put back the original components, as they will have been matched to each other and to the heads etc. Enjoy the weekend, Nick.