Post by mastertech on Dec 21, 2016 21:24:32 GMT -5
It looks like a lot of Onkyo AVR's are having main relay failures on the power supply board. The original relay is a 9 volt coil but the supply voltage is 12 volt. I don't know if this is the reason for failures or if it is just a poor relay to begin with. But I have a confirmed drop in replacement 12 volt relay. Just unsolder the old relay and solder in the replacement and you are good to go if that was your original problem.
The relay is available from Mouser. Here is the link to the replacement. Happy fixing.
I have seen this a couple of times. One word of caution on simply replacing the relay with a 12V version is that on some models (I haven't checked all), Onkyo places a 150ohm 1/2W resistor in series with the relay. The function of this resistor is to reduce the voltage/current going to that relay but you won't see the voltage drop until the ground is applied from the transistor they use to turn on the relay.
I recently repaired an NR717 that not only had a blown relay but had also fried this transistor (Q9101) and the diode that is in this circuit (D9100). My immediate reaction was to change out the relay but almost immediately, the diode and transistor blew again. What I found was that the 150ohm resistor had degraded to about 147 ohms and was allowing too much voltage/current to be applied to these components. The "fix" was to replace the resistor with a brand new one (measured at 152 ohms) and then change out the transistor/diode pair again. I also replaced the relay with the original spec'd 9V part. The Receiver has now been working perfectly for over a month.
I suspect that these resistors are the root cause of the issues with blown relays and would encourage anyone doing this repair to check the 1/2 watt resistor to make sure it is equal to (or a higher value than) it's spec.
mastertech: Merry Christmas to you too. Not many holiday people around any more.
Dec 26, 2018 14:37:50 GMT -5
stridsvognen: Merry christmas everybody...
Dec 24, 2018 19:10:58 GMT -5
mastertech: Sounds nice. Would love to have many more pictures.
Oct 20, 2018 20:31:04 GMT -5
greg1292: Greetings from Denmark. Lots of ideas knowledge and bucket list. Gabor boards looking very nice indeed
Oct 20, 2018 16:38:34 GMT -5
kevin5418: Anyone has the Velodyne hgs12bg MPS board schematic ? thank U
Oct 6, 2018 0:58:34 GMT -5
mastertech: According to the SM ic711 must be installed with the firmware already in it. It can then later be upgraded. The correct ic is around 50 dollars. If you installed a blank ic it will not work.
Aug 19, 2018 20:01:39 GMT -5
ralph: Hello mastertech, sorry for the delay, if I replaced that IC, I was with short circuit, blocked the 3.3 volt regulator, put a new one but still do nothing, what could I do? Thanks for the reply
Aug 18, 2018 21:48:51 GMT -5
mastertech: Did you replace ic711?
Aug 12, 2018 18:55:42 GMT -5
mastertech: Just to clarify you replaced ic711 (STM32F101ZG), correct?
Aug 10, 2018 20:58:16 GMT -5
ralph: Hello, Mastertech, I'll send it to you
Aug 10, 2018 18:58:46 GMT -5