Yamaha Rx-900u delayed relay click

Odizzieus

Member
When I turn on the receiver for the first time in a day, it takes about 15 minutes before the relay clicks. If I turn off the receiver for an hour or two, the relay still takes time to click. If I turn it off and then back on, it clicks in about 10 seconds
 
There is probably a small dried up capacitor in the protect circuit that's responsible for the RC time constant that establishes the delay time.
 
Look for C190 220µf/6.3 vdc it should be located pretty close to the protect relay.
 
This unit is fresh on my mind after I re-built an amp channel, I found it easy to work on, take the top and bottom covers off, flip so you have access to the bottom. The component layout is shown from the copper side. Leads are auto inserted, so they are kinked, need to be straighten out with the hot iron first. pre-tin first before I remove the solder. Even after you remove the solder, use some very small needle nose pliers to straighten the leads, then they fall out of the holes with no damage.

Good luck, I hope it is that ecap.
 
You have two threads going for the same amp. This does not help to solve your problems.
I have two different problems, I already know what I need to replace to get the amp working again that’s not the issue, the issue is that the relay still doesn’t click shortly after startup. Is there anything else that can affect the timing
 
It might be the amp section that is causing this relay delayed turn-on issue. look at the voltages around Q148,149
 
Look for C190 220µf/6.3 vdc it should be located pretty close to the protect relay.
Did you replace C190. As mentioned it is part of the timing for relay activation. It is a 6.3Vdc item, such low voltage caps generally have a
bad history of failing. If the cap is leaking, it will "never" charge up. Next step would be to measure dc offset to confirm ok then look for other
failed components in protection circuit.
 
Did you replace C190. As mentioned it is part of the timing for relay activation. It is a 6.3Vdc item, such low voltage caps generally have a
bad history of failing. If the cap is leaking, it will "never" charge up. Next step would be to measure dc offset to confirm ok then look for other
failed components in protection circuit.
C190 was replaced with no result
 
enerally, the two scenarios are,
- excessive dc voltage on speaker line so protection circuit does
not operate the speaker relay
- failure (component/conncetion,,,) in the protection circuit.

Measure dc voltage, black probe connected to GND/Chassis at both sides
of R283, repeat for both sides of R284,285,286 as per pix

upload_2018-8-22_13-41-7.png
 
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