Dynatron GR5 & GR8 pilot light issue - UK Vintage Radio Repair and Restoration Discussion Forum

Ekcoman · 29th Feb 2020, 7:31 am

No sure why on both of my Dynatrons the red pilot light every now and goes off after a period and then comes back on randomly? Replaced the bulbs, checked the bulb holder and wiring and all seems fine. It doesn't affect in any way the working of the players.

Nuvistor · 29th Feb 2020, 8:40 am

The bulb in the GR8 is wired across the heaters so if the heaters are not going out it can only be the wiring, bulb holder or bulb. Have you replaced both bulbs? Could be a faulty batch.
I don’t have a circuit for the GR5.

vidjoman · 29th Feb 2020, 10:03 am

I've seen this type of fault and it has been due to lampholders that have a sprung centre contact making bad contact with the riveted solder tag (usually plated brass) that had corroded. A good cleaning sometimes cured the fault for a time.

Ekcoman · 29th Feb 2020, 11:12 am

Have replaced both bulbs and in both and neither sprung centre contacts. Guessing it is the wiring but maybe it is something to do with heat as takes a fair while of being left switched on before it happens, never when machines are still cold.

Ekcoman · 4th Mar 2020, 8:32 pm

I'm now going to replace the bulb so wondering if I would replace with a 12v or 9v?

Nuvistor · 4th Mar 2020, 9:17 pm

The manual for GR8 states 8v 300 ma so if you can get 9v 300ma for a reasonable price I would try those.

Ekcoman · 4th Mar 2020, 9:21 pm

Quote:

Originally Posted by Nuvistor

The manual for GR8 states 8v 300 ma so if you can get 9v 300ma for a reasonable price I would try those.

Thanks. I was debating which one so thats helped me decide

29th Feb 2020, 7:31 am	#1
Ekcoman Heptode Join Date: Jan 2008 Location: Southend, Essex, UK Posts: 663	Dynatron GR5 & GR8 pilot light issue No sure why on both of my Dynatrons the red pilot light every now and goes off after a period and then comes back on randomly? Replaced the bulbs, checked the bulb holder and wiring and all seems fine. It doesn't affect in any way the working of the players. Attached Thumbnails __________________ "I really am seriously downsizing "

29th Feb 2020, 8:40 am	#2
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: Dynatron GR5 & GR8 pilot light issue The bulb in the GR8 is wired across the heaters so if the heaters are not going out it can only be the wiring, bulb holder or bulb. Have you replaced both bulbs? Could be a faulty batch. I don’t have a circuit for the GR5. __________________ Frank

29th Feb 2020, 10:03 am	#3
vidjoman Dekatron Join Date: Jun 2013 Location: East Sussex, UK. Posts: 3,327	Re: Dynatron GR5 & GR8 pilot light issue I've seen this type of fault and it has been due to lampholders that have a sprung centre contact making bad contact with the riveted solder tag (usually plated brass) that had corroded. A good cleaning sometimes cured the fault for a time.

29th Feb 2020, 11:12 am	#4
Ekcoman Heptode Join Date: Jan 2008 Location: Southend, Essex, UK Posts: 663	Re: Dynatron GR5 & GR8 pilot light issue Have replaced both bulbs and in both and neither sprung centre contacts. Guessing it is the wiring but maybe it is something to do with heat as takes a fair while of being left switched on before it happens, never when machines are still cold. __________________ "I really am seriously downsizing "

4th Mar 2020, 8:32 pm	#5
Ekcoman Heptode Join Date: Jan 2008 Location: Southend, Essex, UK Posts: 663	Re: Dynatron GR5 & GR8 pilot light issue I'm now going to replace the bulb so wondering if I would replace with a 12v or 9v? __________________ "I really am seriously downsizing "

4th Mar 2020, 9:17 pm	#6
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: Dynatron GR5 & GR8 pilot light issue The manual for GR8 states 8v 300 ma so if you can get 9v 300ma for a reasonable price I would try those. __________________ Frank