Philips N4520 counter - UK Vintage Radio Repair and Restoration Discussion Forum

NorfolkDaveUK · 22nd Aug 2018, 4:16 pm

So, I`ve just had a total disaster with my N4520 .

I waited 6 weeks for an IC to arrive for the counter (long story) put it in and it lights up but all the dots are still there and it doesnt count .

The main issue though its it messed with the transport for some reason and it kinda just started doing its own thing and the tape go caught around the left hand tentioner and broke the darn cap off (snapped the thread on the end of the rod off) . I know these are known for failing , but does anyone know of a fix that allows me to keep the cap ? I can put something through from the opposite direction but that would mean loosing the cap and spoiling the look .

Also , anyone have any idea what might be up with the counter ? Its a new IC, and all new transistors . From what I can tell it should come on with all the dots showing and then the dots should go out and it should then be ready to count but all the dots just stay on.

Thanks for all your help guys . I know I ask a lot of you all I have way too many of these things .lol .

NorfolkDaveUK · 22nd Aug 2018, 6:13 pm

OK , progress , the dots now go out apart from the one that should stay on , but it still doesnt count , I`ll think of something for the tension arm its more an annoyance than anything . I`m going to go through the wiring and see if I made an error when I rebuilt it .

kevinaston1 · 22nd Aug 2018, 8:24 pm

No reset? Check C472 is not open circuit.

Kevin

NorfolkDaveUK · 22nd Aug 2018, 8:47 pm

Hi Kevin, yeah reset is working ok . I`m having some weird goings on at the min , when I press play its shorting out the counter and the lights so something is amiss with the wiring somewhere I should think . I`ll get back to it in a little while .Food time .

NorfolkDaveUK · 23rd Aug 2018, 12:37 am

I figured out where the short was , it was on the remote control socket of all places , wire had come off and was short to ground . So thats sorted . Now I just need to figure out why it wont stay in play . I`m guessing its not sensing a tape is in or the tape end foil sensor is kicking in , so I guess I`ll have a dig around there tomorrow and see if something is amiss there . the tensions arms are working because if I hold the FF / REW or PLAY buttons in and pull down on the tension arm the machine will speed up . So its sensing something . I`m wondering if maybe the foil sensor is short , I`ll have a gander at that tomorrow too . Had that issue one one of my other machines . Counter is still not counting though , so maybe the sensors round the wheel thing arent working , I dunno .

NorfolkDaveUK · 23rd Aug 2018, 8:44 am

Kevin .
Is it possible that , with the counter stuck at 0 , this would stop the tape from engaging play / ff/ rew ? I read somewhere that the machine uses the counter as a tape end sensor . The manual I have is in German and my limited German (frankfurter , Vater and Mutter ) isnt going to cut it .

NorfolkDaveUK · 23rd Aug 2018, 10:03 am

OK i`ve tested the sensor in the counter circuit and it appears the emitters are duff . The receivers seem to be ok as when I shine a bright light in to them the counter is counting so now i need to find a solution for that . Back on the shelf it goes for a while .

22nd Aug 2018, 4:16 pm	#1
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Philips N4520 counter So, I`ve just had a total disaster with my N4520 . I waited 6 weeks for an IC to arrive for the counter (long story) put it in and it lights up but all the dots are still there and it doesnt count . The main issue though its it messed with the transport for some reason and it kinda just started doing its own thing and the tape go caught around the left hand tentioner and broke the darn cap off (snapped the thread on the end of the rod off) . I know these are known for failing , but does anyone know of a fix that allows me to keep the cap ? I can put something through from the opposite direction but that would mean loosing the cap and spoiling the look . Also , anyone have any idea what might be up with the counter ? Its a new IC, and all new transistors . From what I can tell it should come on with all the dots showing and then the dots should go out and it should then be ready to count but all the dots just stay on. Thanks for all your help guys . I know I ask a lot of you all I have way too many of these things .lol .

22nd Aug 2018, 6:13 pm	#2
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Philips N4520 counter OK , progress , the dots now go out apart from the one that should stay on , but it still doesnt count , I`ll think of something for the tension arm its more an annoyance than anything . I`m going to go through the wiring and see if I made an error when I rebuilt it .

22nd Aug 2018, 8:24 pm	#3
kevinaston1 Hexode Join Date: Aug 2014 Location: Featherstone, West Yorkshire, UK. Posts: 386	Re: Philips N4520 counter No reset? Check C472 is not open circuit. Kevin

22nd Aug 2018, 8:47 pm	#4
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Philips N4520 counter Hi Kevin, yeah reset is working ok . I`m having some weird goings on at the min , when I press play its shorting out the counter and the lights so something is amiss with the wiring somewhere I should think . I`ll get back to it in a little while .Food time .

23rd Aug 2018, 12:37 am	#5
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Philips N4520 counter I figured out where the short was , it was on the remote control socket of all places , wire had come off and was short to ground . So thats sorted . Now I just need to figure out why it wont stay in play . I`m guessing its not sensing a tape is in or the tape end foil sensor is kicking in , so I guess I`ll have a dig around there tomorrow and see if something is amiss there . the tensions arms are working because if I hold the FF / REW or PLAY buttons in and pull down on the tension arm the machine will speed up . So its sensing something . I`m wondering if maybe the foil sensor is short , I`ll have a gander at that tomorrow too . Had that issue one one of my other machines . Counter is still not counting though , so maybe the sensors round the wheel thing arent working , I dunno .

23rd Aug 2018, 8:44 am	#6
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Philips N4520 counter Kevin . Is it possible that , with the counter stuck at 0 , this would stop the tape from engaging play / ff/ rew ? I read somewhere that the machine uses the counter as a tape end sensor . The manual I have is in German and my limited German (frankfurter , Vater and Mutter ) isnt going to cut it . Last edited by NorfolkDaveUK; 23rd Aug 2018 at 9:03 am.

23rd Aug 2018, 10:03 am	#7
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Philips N4520 counter OK i`ve tested the sensor in the counter circuit and it appears the emitters are duff . The receivers seem to be ok as when I shine a bright light in to them the counter is counting so now i need to find a solution for that . Back on the shelf it goes for a while .