Update
Hi, Progress.
lanchile - do you mean the Pre to Power links in the phono sockets? They're all in.
I took the meter to relay 3. I could find no voltage in its coil! Up the other end of that relay, I have audio driving a speaker. I turn off Centre and Surround and put the Amp in Direct mode, ( 2 channel stereo?), and have audio. Nothing on the middle pins, where I assume the Relay's output to be, if a voltage was present at its coil!
Thank you
Hi, Progress.
lanchile - do you mean the Pre to Power links in the phono sockets? They're all in.
I took the meter to relay 3. I could find no voltage in its coil! Up the other end of that relay, I have audio driving a speaker. I turn off Centre and Surround and put the Amp in Direct mode, ( 2 channel stereo?), and have audio. Nothing on the middle pins, where I assume the Relay's output to be, if a voltage was present at its coil!
Thank you
Attachments
To me it looks like the amp ends of the relay is the end opposite the coil. Are you saying you have a signal there? Is it clean sounding? If so and no significant DC offset there is something wrong in the protection circuit. Jumper the relay terminals and know that you have no protection if the amp goes to a rail. At least you'll have music.
Not having any voltage across the coils makes sense - the amp is trying to protect your speakers from a fault. real or perceived.
Not having any voltage across the coils makes sense - the amp is trying to protect your speakers from a fault. real or perceived.
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Hi BobEllis,
My lowest meter range is 2.5v! The needle doesn't budge. So I guess no DC. I have three switches to turn speakers on and off. Only the front switch doesn't click the relay, the centre and rear do. And yet, I have nothing coming out of the centre channel?? I know I'm using the audio out, L/R phono, but I get a simulated rear effect, thought it might try to create an artificial centre too.
My lowest meter range is 2.5v! The needle doesn't budge. So I guess no DC. I have three switches to turn speakers on and off. Only the front switch doesn't click the relay, the centre and rear do. And yet, I have nothing coming out of the centre channel?? I know I'm using the audio out, L/R phono, but I get a simulated rear effect, thought it might try to create an artificial centre too.
Are you saying the end pins on the center channel relay have no signal?
Is there an audio signal to the center channel? Are you feeding the receiver a movie? Try plugging a signal directly to the Rear panel input and see what happens.
It sounds more and more like your issue is the protection circuit tripping in error. Does the service manual talk about troubleshooting the protection circuit? With power off can you measure the resistance of the relay coils? It seems unlikely that two relays would fail at once but I suppose its possible.
Troubleshooting the protection circuit can be difficult but a good learning experience. I lean towards soldering a bit of wire from the end pins of the relay where you get audio to the corresponding center pin to send the signal to the rear binding posts.
Is there an audio signal to the center channel? Are you feeding the receiver a movie? Try plugging a signal directly to the Rear panel input and see what happens.
It sounds more and more like your issue is the protection circuit tripping in error. Does the service manual talk about troubleshooting the protection circuit? With power off can you measure the resistance of the relay coils? It seems unlikely that two relays would fail at once but I suppose its possible.
Troubleshooting the protection circuit can be difficult but a good learning experience. I lean towards soldering a bit of wire from the end pins of the relay where you get audio to the corresponding center pin to send the signal to the rear binding posts.
Hi,
I checked all you threads and you do not mentioned in any of them that check all the PS voltages. Did you checked the +/- 56, +/- 27 and the +/- 12 volts. Before you keep troubleshoot the amplifier you need to make sure that all the voltages are OKAY by the voltages indicated in the schematic. just a comment.
I checked all you threads and you do not mentioned in any of them that check all the PS voltages. Did you checked the +/- 56, +/- 27 and the +/- 12 volts. Before you keep troubleshoot the amplifier you need to make sure that all the voltages are OKAY by the voltages indicated in the schematic. just a comment.
At last
Hi all, its working, apart from center channel!
Good point tauro0221, however I found some relays did click, so I assumed the relay psu supply to be okay.
I have it in the lounge, atop my media PC. I'll run it for a couple of days see if it produces smoke. I could always add an active center speaker.
I have a Yamaha in my bedroom. Its fully HD ready with Optical and Coax spdif. Its a full 7:1 system. I'm using it as stereo, what a waste
Thanks for all you're help. I solder up the relays on the main board. We're having a heatwave here in England and the rest of Britain, so its too hot to delve into why the relays are in protect, my suspicion is the Center channel.
I'll let you know if it dies.
Mike
Hi all, its working, apart from center channel!
Good point tauro0221, however I found some relays did click, so I assumed the relay psu supply to be okay.
I have it in the lounge, atop my media PC. I'll run it for a couple of days see if it produces smoke. I could always add an active center speaker.
I have a Yamaha in my bedroom. Its fully HD ready with Optical and Coax spdif. Its a full 7:1 system. I'm using it as stereo, what a waste
Thanks for all you're help. I solder up the relays on the main board. We're having a heatwave here in England and the rest of Britain, so its too hot to delve into why the relays are in protect, my suspicion is the Center channel.
I'll let you know if it dies.
Mike
Attachments
Deafuser, there has been many useful comments to aid troubleshoot on this amplifier...
Check the supply feeds to the relay coils this may range from 12 to 24 volts and fed back to a zener/reg supply for this. some Protection circuits trigger in cases of over voltage/s/c or dc/ or thermal..
If the relay is not closing and as you say your getting sound then trace back to the coil that feeds from the emitter resistors of the o/p devices and tack solder a lead...... relay latch circuit is controlled via switching transistors or chip ic there will also be a filter type made up of a resistor/cap then feed to a small bunch of transistors and if it 'sees' a volt or more at the o/p it will hold off the relay has long as there's high dc.
Relay's can be checked out of circuit via using a battery of 12v just to see if it clicks.
Check the supply feeds to the relay coils this may range from 12 to 24 volts and fed back to a zener/reg supply for this. some Protection circuits trigger in cases of over voltage/s/c or dc/ or thermal..
If the relay is not closing and as you say your getting sound then trace back to the coil that feeds from the emitter resistors of the o/p devices and tack solder a lead...... relay latch circuit is controlled via switching transistors or chip ic there will also be a filter type made up of a resistor/cap then feed to a small bunch of transistors and if it 'sees' a volt or more at the o/p it will hold off the relay has long as there's high dc.
Relay's can be checked out of circuit via using a battery of 12v just to see if it clicks.
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