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Louie, Technician
Category: Home Theater-Stereo
Satisfied Customers: 11640
Experience:  Have been in the business 25+ yrs., down to component level.
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My Yamaha model HTR-5590 will turn off in a second, the display

Customer Question

My Yamaha model HTR-5590 will turn off in a second, the display flashes and then off. All connections removed. I am a tech and found some cracked solder joints around the relays on the power supply board, I fix those, resistor 169 was burned, I replace that still the same. From the AC outlets I get a momentary 120 volts and then zero. I am thinking that is a power supply problem, like a diode or a small transistor is out of value or leaky. I checked all the power transistor and all good.. How can I isolate the power supply to turn on with all disconnected?
Submitted: 1 year ago.
Category: Home Theater-Stereo
Expert:  Rusty replied 1 year ago.
Hello, my name is Rusty. First, let me give you a copy of the service manual,
The download link is below the picture.
Disconnect the six ribbon cables from the power supply feeding the other boards.
Check the output of the large filter caps in the power supply. This is usually where you will find the power supply problems. Sometimes the transformer can die, which isn't a good symptom to have. With all of the boards disconnected from the power supply, tell me the reading off of the large filter caps in the power supply.
Customer: replied 1 year ago.
Good morning,C59 filter cap is at 9.2 volts and C60 filter cap 0 volts
Expert:  Rusty replied 1 year ago.
That looks like the problem. You can get the value off of the cap and order it from Pull on the cap and read the voltage. Does it change? Holes get burned on the inside of them over time. When you replace one, replace the other one as well. They are usually around $8 each.
Customer: replied 1 year ago.
I only have one problem with that answer is that the caps ESR OK and my Z meter also says they are good???
Expert:  Rusty replied 1 year ago.
Well if you're reading 0 volts, that tells me that it's not passing power. If you have one that reads and the second that does not, that's usually the problem.
Customer: replied 1 year ago.
OK, I took my external power supply and loaded the caps with 12 volts and they are holding that just fine? What about R169 what would cause that to be burned?
Customer: replied 1 year ago.
Rusty the caps are still sitting here with a full 13.2 volts? I would think that means they are OK?
Expert:  Rusty replied 1 year ago.
It sounds like they are fine, give me a minute or two to look at the R169 schematic.
Expert:  Rusty replied 1 year ago.
Which PCB is the R169 located?
Customer: replied 1 year ago.
power supply, same board has the filter caps
Customer: replied 1 year ago.
What voltage is suppose to go into the filter caps, I can not find them on the schematics?
Expert:  Rusty replied 1 year ago.
That's a good question, but to test filter caps I've always relied on "are they outputting or not". Without a schematic, that can tell us a lot with little research. I'm still not finding R169. I have located R269, but nothing in the 100s in the schematic. It's looking like 8VDC is what goes into the filter caps. Is that what you are reading? Remember, these caps are only to eliminate the clicking when the AC goes through the diode to change it to DC.
Customer: replied 1 year ago.
Rusty, the resistor is on the main, same board has the filter caps, the caps I checked were on the main, that is what they call it in the service manual, I thought that was the power supply board? there is a small board attached to the main that the power cord is plugged into and another plug that supplies the 120 V to the transformer?
Expert:  Rusty replied 1 year ago.
I'm going to open this question back up. Hopefully another expert will have more experience with that power PCB. Don't rate my answer, and you won't be charged for my time.
Customer: replied 1 year ago.
OK, thanks for your help, sorry we could not figure it out. Have a great day. Robert
Expert:  Louie replied 1 year ago.
Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, for the listed concerns, can you please check:• display flashes - is -32.5 present/consistent at the emitter of Q50;• resistor 169 was burned - zener diode D38 and regulator transistor Q50;• AC outlets...momentary 120 volts and then zero - coincides with relay RY3 kicking off;• C59 & C60 - ± 60V if relay RY3 is engaged;• small board - standby power supply / is +9.2V present/consistent at the collector of Q51. Please post back results / observations of the above once tried.
Customer: replied 1 year ago.
Hi Louie
I will complete those test tomorrow and give you the results.
Expert:  Louie replied 1 year ago.
Appreciate the post back and an update when able.
Customer: replied 1 year ago.
Good morning Louie,
Here are the results of the requested test: The 32.5 is present at the emitter of Q50 only when the relay RY3 is activated by pressing the power on button after is disengages the voltages goes down to zero, D38 and Q50 test good with my fluke tester.
C59 and C 60 also have 59 V only when RY3 is engaged. And also the 120 V from the outlets is the same only there when relay 3 is engaged. I could not find Q512 on the standby supply I only have Q53 and Q56 on the small board that stands up and is connected to the main. The collector of Q53 will have 9.2 volts when I press the power button but on standby it has 12V? Relay 4 and 5 never engage on the main board?
Expert:  Louie replied 1 year ago.
Please re-confirm that it is a -32.5 at the emitter of Q50.
I understand; no Q512/Q51 and only Q53 & Q56. A different version then perhaps of the standby circuit.
Still, please measure the voltage at the base and collector of Q56 during standby, when attempting to turn on and when the relay has clicked Off.
Customer: replied 1 year ago.
The voltage is 37.6 V @Q50 emitter. there is no voltage on Q56. The voltage on the collector of Q53 is 12V relay open and 9.4V relay closed
Expert:  Louie replied 1 year ago.
I was expecting the voltage at the emitter of Q50 to be negative; -32.5
...and base of Q56 to have +0.7V when attempting to turn on with its collector at standby to +9.2 going to 0V when relays engages.
Customer: replied 1 year ago.
Well Louie, there are not, and relay 4 and 5 on the main never energize. I tested again and there is no voltage at Q56. And the voltage from Q50 is the same on the collector, emitter and base? Relay 4 and 5 on the main should energize a few seconds after relay 3 energize on the power supply. I think there is a problem on the main but I tested all components and found none to be defective but I am not 100% sure?
Expert:  Louie replied 1 year ago.
Hi again and thanks for bearing with me.
Please see for the schematics of the standby power supply that may serve as reference since it is likely that what you have may be a slightly different version.
...and for the regulator circuits where the R169 is part of.
Customer: replied 1 year ago.
Good morning Louie
Thanks for your help, we have an associate that had Yamaha of the same model that was damaged during shipping, we purchased the main and the power supply. Installing these repaired the unit. Have a great 4th of July
Customer: replied 1 year ago.
Next week I would like to talk to you about another Yamaha if you are available?
Expert:  Louie replied 1 year ago.
Great! Good to hear that the issue has been resolved, congratulations.
Glad that the above information helped serve your purpose and would appreciate a rating if so warranted (if haven't done so).
Good luck and thank you too for the opportunity to be able to share the information.
Customer: replied 1 year ago.
Hi again Louie,Can you try to help me with this Yamaha RXV573?
Expert:  Louie replied 1 year ago.
Yes of course. Please click HERE to open a new question prefixed with something like the question HERE.