Dynatron SRX 30B / Philips N2506 cassette - UK Vintage Radio Repair and Restoration Discussion Forum

tonyj154 · 11th May 2021, 10:29 pm

Picked up a fully working wonderful example of a Dynatron Cavalcade SRX 30B today. Bill of sale, all guarantees and warrantees, lots of paperwork and serviced 3 times.
The radio and turntable are fine (after re-lubing the turntable bearings etc) The Philips N2506 cassette is as dead as a dodo.
I've dismantled and cleaned the 48 year dust away and cannot see anything obviously wrong with the Philips N2506unit... so where do I start??

The unit does not lit up at all. The the connecters are in the appropriate holes, the belts are good but there's just no sign of life from it...

Any ideas??

Edward Huggins · 12th May 2021, 9:24 am

Have you tested the voltage feed into the tape unit's chassis?

tonyj154 · 12th May 2021, 12:44 pm

I've plugged it all back in and now when the TAPE is selected there's buzzing from speakers, the player makes no effort to play.

ben · 12th May 2021, 2:33 pm

If the deck has a separate power switch check it makes contact. Philips mains switches of this era were problematical.

You will have to remove the inevitable Philips goo /tar from the old disintegrated belts too!

DMcMahon · 12th May 2021, 2:35 pm

As per Edwards question, when you switch the N2506 on by pushing its front panel on/off push switch does the indicator next to it light up to show power is available ?

If not then either the indicator bulb/lamp is defective or there is no power.

240 volts mains voltage comes into the N2506 and then its power supply electronics generate 6 DC power supply rails identified on the schematic as A to F. The F supply (9V) comes from a regulating/stabilising transistor (TS406) and additionally powers a lamp (LA405) which I assume must be the power on indicator.

So if the lamp is not lighting and the lamp itself is good then this either means that N2506 is not getting the 240V mains supply from the Dynatron chassis or there is a problem with the N2506 power supply. There are 2 fuses for this power supply, mains fuse Z1 (1.5A) and HT fuse Z468 (630mA) these fuses may be inside the N2506 unit as opposed to on its rear panel.

So if 240V mains is getting to the N2506 then check the fuses.

David

11th May 2021, 10:29 pm	#1
tonyj154 Diode Join Date: May 2021 Location: Lincolnshire, UK. Posts: 6	Dynatron SRX 30B / Philips N2506 cassette Picked up a fully working wonderful example of a Dynatron Cavalcade SRX 30B today. Bill of sale, all guarantees and warrantees, lots of paperwork and serviced 3 times. The radio and turntable are fine (after re-lubing the turntable bearings etc) The Philips N2506 cassette is as dead as a dodo. I've dismantled and cleaned the 48 year dust away and cannot see anything obviously wrong with the Philips N2506unit... so where do I start?? The unit does not lit up at all. The the connecters are in the appropriate holes, the belts are good but there's just no sign of life from it... Any ideas??

12th May 2021, 9:24 am	#2
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,324	Re: Dynatron SRX 30B / Philips N2506 cassette Have you tested the voltage feed into the tape unit's chassis? __________________ Edward.

12th May 2021, 12:44 pm	#3
tonyj154 Diode Join Date: May 2021 Location: Lincolnshire, UK. Posts: 6	Re: Dynatron SRX 30B / Philips N2506 cassette I've plugged it all back in and now when the TAPE is selected there's buzzing from speakers, the player makes no effort to play.

12th May 2021, 2:33 pm	#4
ben Dekatron Join Date: Aug 2006 Location: Madrid, Spain / Wirral, UK Posts: 7,498	Re: Dynatron SRX 30B / Philips N2506 cassette If the deck has a separate power switch check it makes contact. Philips mains switches of this era were problematical. You will have to remove the inevitable Philips goo /tar from the old disintegrated belts too! __________________ Regards, Ben.

12th May 2021, 2:35 pm	#5
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 6,600	Re: Dynatron SRX 30B / Philips N2506 cassette As per Edwards question, when you switch the N2506 on by pushing its front panel on/off push switch does the indicator next to it light up to show power is available ? If not then either the indicator bulb/lamp is defective or there is no power. 240 volts mains voltage comes into the N2506 and then its power supply electronics generate 6 DC power supply rails identified on the schematic as A to F. The F supply (9V) comes from a regulating/stabilising transistor (TS406) and additionally powers a lamp (LA405) which I assume must be the power on indicator. So if the lamp is not lighting and the lamp itself is good then this either means that N2506 is not getting the 240V mains supply from the Dynatron chassis or there is a problem with the N2506 power supply. There are 2 fuses for this power supply, mains fuse Z1 (1.5A) and HT fuse Z468 (630mA) these fuses may be inside the N2506 unit as opposed to on its rear panel. So if 240V mains is getting to the N2506 then check the fuses. David