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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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Sony STR-DE875 Channels Dropping Out
I have had a Sony STR-DE875 amplifier for nearly two problem free
years. It now seems that a couple of channels are dropping out occasionally predominantly with the centre speaker although there is a very noticable degredation of sound accross the the front three speakers. I have done the test tones when the channels have dropped and the centre one is completely missing at this point. There is also an intermittant audible "click" when the unit has failed much like the click when the unit is switched on. I do have two units on top of the amp (sky and dvd) but these have always been there and have not caused any problems in the past. I have seen a few messages that mention overheating but why would the unit be overheating now and not before. Many thanks Alex |
#2
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"Alex C" wrote in message om... I have had a Sony STR-DE875 amplifier for nearly two problem free years. It now seems that a couple of channels are dropping out occasionally predominantly with the centre speaker although there is a very noticable degredation of sound accross the the front three speakers. I have done the test tones when the channels have dropped and the centre one is completely missing at this point. There is also an intermittant audible "click" when the unit has failed much like the click when the unit is switched on. I do have two units on top of the amp (sky and dvd) but these have always been there and have not caused any problems in the past. I have seen a few messages that mention overheating but why would the unit be overheating now and not before. Many thanks Alex Check the pre amp ic's for dry joints |
#3
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Solder connection(s) at one or more relays? I was going to suggest solder
connections at the rear panel, which ought to be checked anyway, but the reference to the "click" made me think of the relay. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Alex C" wrote in message om... I have had a Sony STR-DE875 amplifier for nearly two problem free years. It now seems that a couple of channels are dropping out occasionally predominantly with the centre speaker although there is a very noticable degredation of sound accross the the front three speakers. I have done the test tones when the channels have dropped and the centre one is completely missing at this point. There is also an intermittant audible "click" when the unit has failed much like the click when the unit is switched on. I do have two units on top of the amp (sky and dvd) but these have always been there and have not caused any problems in the past. I have seen a few messages that mention overheating but why would the unit be overheating now and not before. Many thanks Alex |
#4
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"Mark D. Zacharias" wrote in message ...
Solder connection(s) at one or more relays? I was going to suggest solder connections at the rear panel, which ought to be checked anyway, but the reference to the "click" made me think of the relay. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Alex C" wrote in message om... I have had a Sony STR-DE875 amplifier for nearly two problem free years. It now seems that a couple of channels are dropping out occasionally predominantly with the centre speaker although there is a very noticable degredation of sound accross the the front three speakers. I have done the test tones when the channels have dropped and the centre one is completely missing at this point. There is also an intermittant audible "click" when the unit has failed much like the click when the unit is switched on. I do have two units on top of the amp (sky and dvd) but these have always been there and have not caused any problems in the past. I have seen a few messages that mention overheating but why would the unit be overheating now and not before. Many thanks Alex Thanks guys |
#5
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Alex C wrote:
"Mark D. Zacharias" wrote in message ... Solder connection(s) at one or more relays? I was going to suggest solder connections at the rear panel, which ought to be checked anyway, but the reference to the "click" made me think of the relay. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Alex C" wrote in message om... I have had a Sony STR-DE875 amplifier for nearly two problem free years. It now seems that a couple of channels are dropping out occasionally predominantly with the centre speaker although there is a very noticable degredation of sound accross the the front three speakers. I have done the test tones when the channels have dropped and the centre one is completely missing at this point. There is also an intermittant audible "click" when the unit has failed much like the click when the unit is switched on. I do have two units on top of the amp (sky and dvd) but these have always been there and have not caused any problems in the past. I have seen a few messages that mention overheating but why would the unit be overheating now and not before. Many thanks Alex Thanks guys I would definitely rearrange your setup. It could be that the cumulative effect of long term, low grade overheating has caused your problem...assuming it's internal. The very first thing I would check, however, is all every speaker connection. Sounds stupid, but one little 'whisker' of wire protruding out of a speaker connector shorting against the chassis 'could' cause your symptoms. Likewise a loose screw terminal; or corrosion or weak spring on a spring terminal. I've seen all of the above...in a addition to people inserting the insulated portion of the lead into a spring terminal. The wire itself was not actually clamped, but was 'just' touching internally--enough to 'usually' work. jak |
#6
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All true, but in this case it is likely just a tendency in these units for
the solder joints to crack. We see them frequently. Leonard "jakdedert" wrote in message news Alex C wrote: "Mark D. Zacharias" wrote in message ... Solder connection(s) at one or more relays? I was going to suggest solder connections at the rear panel, which ought to be checked anyway, but the reference to the "click" made me think of the relay. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Alex C" wrote in message om... I have had a Sony STR-DE875 amplifier for nearly two problem free years. It now seems that a couple of channels are dropping out occasionally predominantly with the centre speaker although there is a very noticable degredation of sound accross the the front three speakers. I have done the test tones when the channels have dropped and the centre one is completely missing at this point. There is also an intermittant audible "click" when the unit has failed much like the click when the unit is switched on. I do have two units on top of the amp (sky and dvd) but these have always been there and have not caused any problems in the past. I have seen a few messages that mention overheating but why would the unit be overheating now and not before. Many thanks Alex Thanks guys I would definitely rearrange your setup. It could be that the cumulative effect of long term, low grade overheating has caused your problem...assuming it's internal. The very first thing I would check, however, is all every speaker connection. Sounds stupid, but one little 'whisker' of wire protruding out of a speaker connector shorting against the chassis 'could' cause your symptoms. Likewise a loose screw terminal; or corrosion or weak spring on a spring terminal. I've seen all of the above...in a addition to people inserting the insulated portion of the lead into a spring terminal. The wire itself was not actually clamped, but was 'just' touching internally--enough to 'usually' work. jak |
#7
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Leonard Caillouet wrote:
All true, but in this case it is likely just a tendency in these units for the solder joints to crack. We see them frequently. Probably exacerbated by the lack of circulation in the setup he describes..... jak Leonard "jakdedert" wrote in message news Alex C wrote: "Mark D. Zacharias" wrote in message ... Solder connection(s) at one or more relays? I was going to suggest solder connections at the rear panel, which ought to be checked anyway, but the reference to the "click" made me think of the relay. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Alex C" wrote in message om... I have had a Sony STR-DE875 amplifier for nearly two problem free years. It now seems that a couple of channels are dropping out occasionally predominantly with the centre speaker although there is a very noticable degredation of sound accross the the front three speakers. I have done the test tones when the channels have dropped and the centre one is completely missing at this point. There is also an intermittant audible "click" when the unit has failed much like the click when the unit is switched on. I do have two units on top of the amp (sky and dvd) but these have always been there and have not caused any problems in the past. I have seen a few messages that mention overheating but why would the unit be overheating now and not before. Many thanks Alex Thanks guys I would definitely rearrange your setup. It could be that the cumulative effect of long term, low grade overheating has caused your problem...assuming it's internal. The very first thing I would check, however, is all every speaker connection. Sounds stupid, but one little 'whisker' of wire protruding out of a speaker connector shorting against the chassis 'could' cause your symptoms. Likewise a loose screw terminal; or corrosion or weak spring on a spring terminal. I've seen all of the above...in a addition to people inserting the insulated portion of the lead into a spring terminal. The wire itself was not actually clamped, but was 'just' touching internally--enough to 'usually' work. jak |
#8
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All true, but in this case it is likely just a tendency in these units for the solder joints to crack. We see them frequently. Leonard I'm willing to bet you're right. I've noticed with some Sony stuff that quite a few solder joints are not done very well, usually having too little solder to maintain a reliable connection of a component to a circuit after sometime. - Reinhart |
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