Hi all,
I have a Denon 1290 CD player that abruptly shuts off when the AC voltage approaches ~215V, the CD stops spinning and the display shuts off. I've tested the player on a variac and it works fine up to 215-217VAC while it's a normal 220-230V EU model and also has no voltage selector.
The main voltage regulators do keep producing normal voltage, the usual transistors also stay warm even if the player seems 'dead' at normal line voltage.
Any ideas? I've tried unplugging what can be unplugged and trying again at ~225-230VAC but that doesn't change anything - dead, if I lower the AC, the player wakes up again.
I have a Denon 1290 CD player that abruptly shuts off when the AC voltage approaches ~215V, the CD stops spinning and the display shuts off. I've tested the player on a variac and it works fine up to 215-217VAC while it's a normal 220-230V EU model and also has no voltage selector.
The main voltage regulators do keep producing normal voltage, the usual transistors also stay warm even if the player seems 'dead' at normal line voltage.
Any ideas? I've tried unplugging what can be unplugged and trying again at ~225-230VAC but that doesn't change anything - dead, if I lower the AC, the player wakes up again.
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Have you checked all of your voltage lines for the correct voltage regulation:
Stay safe around mains.
Stay safe around mains.
I think I found it....IC501, 7805A drops output from +5V to +0.6V after the mains reaches the beforementioned ~215-217VAC. Lowering the AC again and the output jumps back to +5V.
IC502/503 outputs are a bit off at around 12-13V but the ICPNI5 are both only surge protector circuits so that's just the rectified DC being higher as the device is designed for 220V.
IC502/503 outputs are a bit off at around 12-13V but the ICPNI5 are both only surge protector circuits so that's just the rectified DC being higher as the device is designed for 220V.
Put a 10W 10E resistor in series with the mains input.
That will drop it to safer range.
End of problem.
Make sure it is not in touch with something, they run hot!
Edit:
Our posts were almost same time...
This trick works, and please put a larger heat sink on the 7805, with a proper layer of heat transfer material.
Also consider a surge suppressor for the mains supply, at the house incoming panel, or on the wall boards where the supply to the unit comes from.
That will drop it to safer range.
End of problem.
Make sure it is not in touch with something, they run hot!
Edit:
Our posts were almost same time...
This trick works, and please put a larger heat sink on the 7805, with a proper layer of heat transfer material.
Also consider a surge suppressor for the mains supply, at the house incoming panel, or on the wall boards where the supply to the unit comes from.
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