No Power to a Home Theater Receiver  - Page 1
Forum section: electronics / beginners

author: Autoelectrical
author_rank: Contributor
timestamp: November 04, 2012, 12:22:05 am
content: I have an Onkyo Integra Home Theater Receiver that refuses to power up at all. The model number is DTR-7.1. I have done at least the very basic task of trying different power cords (it uses a computer style heavy 3 prong cord) but has no ground wire in it to the outlet.There is no smell of burnt components even after taking the cover off. It was plugged into a UPS during its life so that should have taken care of most, not all surges and conditioned the power going into it.Visual inspection of the unit does not show any signs of melted or discolored PCB's. I have found 3 fuses that "look" good but I am going to replace anyway.I am not so much as getting light from the little red led showing that it is getting power from the wall, let alone anything when pressing the power button.I just got my first DMM and would like to know how to do some basic tests on the power switch (to make sure its working) or the components between the plug in the back of the unit to the power switch to see if anything has failed.I am hoping this is a simple fix because I hate to throw the unit out for something stupid that could easily be fixed.This is a link to the manufacturer's page about the device:http://www.integrahometheater.com/model.cfm?m=DTR-7.1&class=Receiver&p=iI should be able to use the DMM to see if the fuse is good or not also?

author: IanB
author_rank: Super Contributor
timestamp: November 04, 2012, 12:37:26 am
content: There's something of a learning curve to this stuff if you are new to the whole thing. Are there any TV/video repairers in your area you could take it to? They will charge you for the repair but most likely will find the fault much faster than you can hope to.

author: retiredcaps
author_rank: Super Contributor
timestamp: November 04, 2012, 01:04:43 am
content: Quote from: Autoelectrical on November 04, 2012, 12:22:05 amPower off your receiver and unplug it from the wall. All resistance measurements are done with power off. Wait 5 or 10 minutes to allow the big filter capacitor to discharge. Be careful, as some do not discharge and can be holding 165 DC or more.Take your Fluke 789, turn it to resistance. Put red probe on one side of the fuse and black on the other side.A good fuse should normally measures less than 1.0 ohms. If the fuse reading shows 0L, then it is blown.PS. A good 5 minute tutorial on multimeter usage by my fellow Canadian at

author: Autoelectrical
author_rank: Contributor
timestamp: November 04, 2012, 03:13:37 am
content: Quote from: IanB on November 04, 2012, 12:37:26 amThere are a few TV/Video repair shops near me but I want to learn, and the quotes I got just to look at the unit are high enough that if I can fix a simple problem, I would prefer to do it myself and it is not something I need fixed in a week, so I can take my time with this one.

author: Autoelectrical
author_rank: Contributor
timestamp: November 04, 2012, 03:15:01 am
content: Quote from: retiredcaps on November 04, 2012, 01:04:43 amHi Retiredcaps,Thank you,I finished watching the video and it helped allot, I nope I am not getting in over my head with this one.

author: Psi
author_rank: Super Contributor
timestamp: November 04, 2012, 09:20:53 am
content: Unfortunately faultfinding is not one of the easy areas in electronics.You have to understand how the device works before you can track down faults.That said, there are lots of common faults that aren't hard to check and only require semi-basic electronic knowledge.Things like changing fuses, replacing obviously blown components or bulging caps and fixing dry solder jointsAlso checking for a failed bootstrap resistor in switchmode powersupplies.

author: mariush
author_rank: Super Contributor
timestamp: November 04, 2012, 10:52:11 pm
content: Well, if you think it would help you, here's the service manual along with other bits of information:http://savedonthe.net/a/onkyo_dtr-7.1.rarI'd suggest checking the fuses, then going through the power supply section and measure the voltages at certain points... See where the wires from the power on button go and try to measure the voltage at that connection point of the wire before and at the moment you press the button... etcAccording to the service manual, it has a microprocessor which is powered from 5v so there should be a mini power supply to feed it with 5v even when it's not running.

author: Autoelectrical
author_rank: Contributor
timestamp: November 05, 2012, 01:04:29 am
content: Quote from: Psi on November 04, 2012, 09:20:53 amThank you Psi

author: Autoelectrical
author_rank: Contributor
timestamp: November 05, 2012, 01:05:23 am
content: Quote from: mariush on November 04, 2012, 10:52:11 pmHi Mariush, that should help quite a bit, thank you