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Post by tibimakai on May 6, 2018 23:32:54 GMT -5
Fan starts at a certain temperature( I believe 60C degree).
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Post by michelho on May 7, 2018 9:41:56 GMT -5
Fan starts at a certain temperature( I believe 60C degree). I read from mastertech / Guptau chat that the Fan fan start working when we power receiver? |
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Post by tibimakai on May 7, 2018 11:06:02 GMT -5
At least, with the lower level receivers(6 and 7 series), there is only one fan and it does not run all the time. There is a temperature sensor on the big heatsink, and that determines, when should the fan start spinning.
Pretty much, when the receivers gets to hot.
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Post by michelho on May 7, 2018 11:17:09 GMT -5
At least, with the lower level receivers(6 and 7 series), there is only one fan and it does not run all the time. There is a temperature sensor on the big heatsink, and that determines, when should the fan start spinning. Pretty much, when the receivers gets to hot. Thanks for that, thought they were starting on power on (Yes i saw the To transistor attached) Do u know why my receiver is working with the GND-sub of PS board connected to chassis ? |
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Post by mastertech on May 7, 2018 12:40:08 GMT -5
I have no idea why it would work because I don't know if that gnd should be tied to chassis gnd. You will have to search the schematics to see if it should be tied to chassis gnd.. Maybe do an ohm test between that gnd and chassis gnd and see what you get.
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Post by chriswonsowski on May 7, 2018 18:53:11 GMT -5
Hey,I have an ht-r557 that's not lighting up the standby light when plugged in, power button does nothing, and I've found some 12v in areas.
I opened the relay and manually made it contact. The large transformer makes only a slight hum for a few seconds.
Is there a way to bypass the relay entirely just to see if that is the issue?
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Post by mastertech on May 7, 2018 20:37:06 GMT -5
Well if you are manually closing the contacts and holding them closed and still the receiver is not turning on then it is not the relay or at least not just the relay. Are you holding the contacts closed and then pressing the power on button?
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Post by chriswonsowski on May 8, 2018 9:27:17 GMT -5
Correct, holding relay closed > still no standby led > power button does nothing while relay is closed.
I tried testing the relay also by putting DMM to check open/closed on the side of the coil while manually contacting and it stayed open.
I remember this receiver had occasionally worked from time to time, and turned on once while I was just prodding around at things trying to see if it was a loose connection. I haven't been able to reproduce that so far in 6 months.
Is there a way to short the CPU to send the Power On signal? I guess the power button does that but it would help show if the CPU is getting the proper power, right?
This isn't a great receiver and I don't really care about it, I'm just interested in learning the skills and troubleshooting.
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Post by michelho on May 8, 2018 19:51:48 GMT -5
I have no idea why it would work because I don't know if that gnd should be tied to chassis gnd. You will have to search the schematics to see if it should be tied to chassis gnd.. Maybe do an ohm test between that gnd and chassis gnd and see what you get. Hello Mastertech Schematics don't mention anything, they only mark GND SUB (substrate ?) on this connector but physically i don't see a ny connection made to the chassis. Nothing on OHM test, on DIOD test something like a diode response . If I take out the chassis contact the receiver starts and stops in 4 seconds. And what about the fans ? Should they be starting when receiver powers? or only on threshold To ? Thanks for helping |
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Post by mastertech on May 9, 2018 7:37:14 GMT -5
Does the receiver operate normally with that gnd jumper?
I do not know about the fans.
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Post by michelho on May 9, 2018 19:16:16 GMT -5
Does the receiver operate normally with that gnd jumper? I do not know about the fans. With GndSUB to chassis, I see display responding to all buttons pressed, and receiver not shutting down; will test further on Shall I investigate for the regulators like you show to Guptau ? |
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Post by chriswonsowski on May 10, 2018 11:17:39 GMT -5
So after reading about the talk about a ground from the power supply to chassis, I thought I'd take a look at mine. There are two mounting points for the PS board to secure to the chassis, one of those points (the bottom one) is actually connected to the circuit and I figured that was a ground so I screwed it in and it turns on now. Unfortunately months back when everything was connected and untouched is when it wasn't working. So it wasn't just my stupid mistake that was causing it to not work. Could this intermittent issue only be caused by a poor connection somewhere or could it be something else? I've tried jerking connectors around a lot and haven't pinpointed anything yet. Thanks.  |
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Post by mastertech on May 10, 2018 14:12:51 GMT -5
Well how about that. This is a good example why I always tell everyone to not take anything apart unless I tell them to. Even stupid screws cannot just be removed for testing. Anyways, good find.  |
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Post by michelho on May 10, 2018 17:41:42 GMT -5
I have no idea why it would work because I don't know if that gnd should be tied to chassis gnd. You will have to search the schematics to see if it should be tied to chassis gnd.. Maybe do an ohm test between that gnd and chassis gnd and see what you get. Sorry in fact the GND_SUB is well attached to chassis / i did see it, bec ause I have taken the rear panel out and PS was screwed there |
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Post by michelho on May 10, 2018 17:46:22 GMT -5
I have no idea why it would work because I don't know if that gnd should be tied to chassis gnd. You will have to search the schematics to see if it should be tied to chassis gnd.. Maybe do an ohm test between that gnd and chassis gnd and see what you get. In fact the GND SUB must be tied to chassis I forgot because have taken rear panel out; Mea culpa! |
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