Post by nobbsy on Jul 11, 2021 5:22:19 GMT
Hi All,
I really hope you can help me, I've been stuck on this issue for a while (~ 6 months).
When trying to play a record, the jukebox goes through the usual motions and when the muting relay opens all I can hear is a thumping sound, every 1 second or so.
- I have tried removing the input and makes no difference.
- When i remove the muting relay, I can hear it without a record playing as expected
- Turned off turntable motor and can still hear, so not noise from mech
I have gone through the amp checking voltages and all but the preamp seems to be in order.
On the preamp, I get the -15V and the +30V, but the +15V shows up as 0.15V.
I've traced back from the +15V line to the resistor prior to the input into the preamp, removed it and it tests fine. The voltages before this resistor seem ok. 50V from memory. Although as expected, the preamp side of the resistor is 0.15V, so its not the wire.
Has anyone come across anything like this? Is there anything i might be able to check?
I keep thinking it may be an earth issue, but would that cause the PreAmp 15V to reduce down to 0.15V? Asumming the factor of 100 is a co-incidence.
Many thanks
I really hope you can help me, I've been stuck on this issue for a while (~ 6 months).
When trying to play a record, the jukebox goes through the usual motions and when the muting relay opens all I can hear is a thumping sound, every 1 second or so.
- I have tried removing the input and makes no difference.
- When i remove the muting relay, I can hear it without a record playing as expected
- Turned off turntable motor and can still hear, so not noise from mech
I have gone through the amp checking voltages and all but the preamp seems to be in order.
On the preamp, I get the -15V and the +30V, but the +15V shows up as 0.15V.
I've traced back from the +15V line to the resistor prior to the input into the preamp, removed it and it tests fine. The voltages before this resistor seem ok. 50V from memory. Although as expected, the preamp side of the resistor is 0.15V, so its not the wire.
Has anyone come across anything like this? Is there anything i might be able to check?
I keep thinking it may be an earth issue, but would that cause the PreAmp 15V to reduce down to 0.15V? Asumming the factor of 100 is a co-incidence.
Many thanks
