Tandberg 3000x no record. - UK Vintage Radio Repair and Restoration Discussion Forum

NorfolkDaveUK · 2nd Sep 2018, 8:36 pm

So this is the next one i have , this one i bought with "belt go" , there was no goo though , just broken belts, thankfully , it plays so well , really well , but no record or erase , ive tested the transistors and get the following ...

501

base - 16.4 v
collector - 27.2v
emitter - 20.7v

502

base 20.2
collector 20.5
emitter 22.2

503

base 15.17
collector 27.2v
emitter 16.3v

the 501 and 502 voltages are high....but im not too sure what that means , if some one wouldnt mind just explaining that that would be great . I get 20v AC at the record head. I have cleaned the switches to no avail .

ms660 · 2nd Sep 2018, 8:54 pm

According to the schematic I'm looking at, the base's of Q501 & Q502 and the emitter of Q503 are all connected together the same as in your schematic snippet, your voltage measurement on the base of Q502 doesn't support that:

Lawrence.

NorfolkDaveUK · 2nd Sep 2018, 8:58 pm

Would this point to Q502 being borked ?

ms660 · 2nd Sep 2018, 9:11 pm

Your voltage measurement on the base of Q502 should be the same as the voltage on the base of Q501 and the voltage on the emitter of Q503, because according to the schematic they are all connected together, other voltages are off the mark too, you need to check that you've measured correctly and that the what's in the flesh so to speak (components/PCB layout) agrees with what the schematic shows.

Lawrence.

NorfolkDaveUK · 2nd Sep 2018, 9:23 pm

ok i just took the bottom off and ALL of the 503 and 502 joints were broken , I`ve soldered them back and the voltages with record engaged are now :

501
base 14.53
collector 27.2
emitter 14.72

502
base 14.4
collector 0
emitter 14.2

503
base 15.08
collector 27.1
emitter 14.4

I`ll check R503 and R504

I think someone has had the board out and bent those transistors down to get it out .

NorfolkDaveUK · 2nd Sep 2018, 9:42 pm

All fixed , Thanks Lawrence

....I`m learning so much here . I really appreciate you all !!!!!!

NorfolkDaveUK · 2nd Sep 2018, 10:00 pm

Actually its not quite fixed its not quite erasing the tape . I can still hear it in the back ground .....mm .

See_Mos · 3rd Sep 2018, 3:30 pm

Refresh my mind - is the oscillator on a separate small PCB?

If so I think I have one somewhere.

ms660 · 3rd Sep 2018, 4:02 pm

The oscillator is part of one of the main panels, no small separate panel for it so far as I can make out from the manual.

Lawrence.

NorfolkDaveUK · 3rd Sep 2018, 4:49 pm

No its all one board in this machine . (well two boards , one at the bottom and one that stands up and plugs into the one at the bottom) , I haven`t had chance to look at this today, I`ve got a sony that`s giving me grief at the min I`m juggling quite a few at the min as the parts come in I get them fitted. I`m going to wait for a new 5 pin din for this and also add some rca`s . They are on the way now and should be here tomorrow . The 5 pin din in it cuts out really badly so I can`t do a lot with it until I fix that because it drives me nuts ..haha .

2nd Sep 2018, 8:36 pm	#1
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Tandberg 3000x no record. So this is the next one i have , this one i bought with "belt go" , there was no goo though , just broken belts, thankfully , it plays so well , really well , but no record or erase , ive tested the transistors and get the following ... 501 base - 16.4 v collector - 27.2v emitter - 20.7v 502 base 20.2 collector 20.5 emitter 22.2 503 base 15.17 collector 27.2v emitter 16.3v the 501 and 502 voltages are high....but im not too sure what that means , if some one wouldnt mind just explaining that that would be great . I get 20v AC at the record head. I have cleaned the switches to no avail . Attached Thumbnails

2nd Sep 2018, 8:54 pm	#2
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Tandberg 3000x no record. According to the schematic I'm looking at, the base's of Q501 & Q502 and the emitter of Q503 are all connected together the same as in your schematic snippet, your voltage measurement on the base of Q502 doesn't support that: Lawrence.

2nd Sep 2018, 8:58 pm	#3
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Tandberg 3000x no record. Would this point to Q502 being borked ?

2nd Sep 2018, 9:11 pm	#4
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Tandberg 3000x no record. Your voltage measurement on the base of Q502 should be the same as the voltage on the base of Q501 and the voltage on the emitter of Q503, because according to the schematic they are all connected together, other voltages are off the mark too, you need to check that you've measured correctly and that the what's in the flesh so to speak (components/PCB layout) agrees with what the schematic shows. Lawrence. Last edited by ms660; 2nd Sep 2018 at 9:21 pm.

2nd Sep 2018, 9:23 pm	#5
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Tandberg 3000x no record. ok i just took the bottom off and ALL of the 503 and 502 joints were broken , I`ve soldered them back and the voltages with record engaged are now : 501 base 14.53 collector 27.2 emitter 14.72 502 base 14.4 collector 0 emitter 14.2 503 base 15.08 collector 27.1 emitter 14.4 I`ll check R503 and R504 I think someone has had the board out and bent those transistors down to get it out . Last edited by NorfolkDaveUK; 2nd Sep 2018 at 9:30 pm. Reason: spelling

2nd Sep 2018, 9:42 pm	#6
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Tandberg 3000x no record. All fixed , Thanks Lawrence ....I`m learning so much here . I really appreciate you all !!!!!!

2nd Sep 2018, 10:00 pm	#7
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Tandberg 3000x no record. Actually its not quite fixed its not quite erasing the tape . I can still hear it in the back ground .....mm .

3rd Sep 2018, 3:30 pm	#8
See_Mos Hexode Join Date: Nov 2003 Location: Ossett, West Yorkshire, UK. Posts: 483	Re: Tandberg 3000x no record. Refresh my mind - is the oscillator on a separate small PCB? If so I think I have one somewhere.

3rd Sep 2018, 4:02 pm	#9
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Tandberg 3000x no record. The oscillator is part of one of the main panels, no small separate panel for it so far as I can make out from the manual. Lawrence.

3rd Sep 2018, 4:49 pm	#10
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Tandberg 3000x no record. No its all one board in this machine . (well two boards , one at the bottom and one that stands up and plugs into the one at the bottom) , I haven`t had chance to look at this today, I`ve got a sony that`s giving me grief at the min I`m juggling quite a few at the min as the parts come in I get them fitted. I`m going to wait for a new 5 pin din for this and also add some rca`s . They are on the way now and should be here tomorrow . The 5 pin din in it cuts out really badly so I can`t do a lot with it until I fix that because it drives me nuts ..haha .