Hi all,
I'm hoping someone will be able to tell me what the problem is on this unit or steer me towards a reputable repair tech.
I recently got an Onkyo TS-DX777 receiver as part of a swap recently, and despite the trader's assurance (surprise surprise), it has problems (I know, 'caveat emptor').
The unit will power up and appears to work normally, e.g. the remote brings up all the appropriate options on the display, and the AM/FM tuner locks onto local stations.
However, it doesn't put out any power to the speakers (tried several and checked w/a multimeter).
When turned up to maximum volume, a circuit breaker engages and shuts the unit down.
Any help/advice would be GREATLY appreciated.
- Dave
I'm hoping someone will be able to tell me what the problem is on this unit or steer me towards a reputable repair tech.
I recently got an Onkyo TS-DX777 receiver as part of a swap recently, and despite the trader's assurance (surprise surprise), it has problems (I know, 'caveat emptor').
The unit will power up and appears to work normally, e.g. the remote brings up all the appropriate options on the display, and the AM/FM tuner locks onto local stations.
However, it doesn't put out any power to the speakers (tried several and checked w/a multimeter).
When turned up to maximum volume, a circuit breaker engages and shuts the unit down.
Any help/advice would be GREATLY appreciated.
- Dave
Hi All,
First, thanks for chiming in. I checked the speaker wire terminals with a multimeter and there is no voltage reading at any volume level.
I pulled the cover and checked the fuses for continuity, all are fine (should have done this first, sorry).
On visual inspection nothing looks out of place on the boards (no burn marks, capacitors all look OK, etc.).
One interesting thing I noticed is that when first plugged in and the main power is switched on, the fan moves a teeny bit but does not turn on. Subsequent switching on and off doesn't do anything. Unplugging it, waiting a bit, and then plugging back in and turning on the main makes the fan move again.
-Dave
First, thanks for chiming in. I checked the speaker wire terminals with a multimeter and there is no voltage reading at any volume level.
I pulled the cover and checked the fuses for continuity, all are fine (should have done this first, sorry).
On visual inspection nothing looks out of place on the boards (no burn marks, capacitors all look OK, etc.).
One interesting thing I noticed is that when first plugged in and the main power is switched on, the fan moves a teeny bit but does not turn on. Subsequent switching on and off doesn't do anything. Unplugging it, waiting a bit, and then plugging back in and turning on the main makes the fan move again.
-Dave
Ok, there's 4 white twin style resistors about 4mm thick and the size of a postage stamp type BPR55 0.22 Ohm (manufactured by KOA).
Two are on the board with the power capacitors and two are on the daughterboard attached to it.
Are these the guys I should check?
Thanks,
Dave
PS Did I mention you guys are awesome? Ok, there it is.
Two are on the board with the power capacitors and two are on the daughterboard attached to it.
Are these the guys I should check?
Thanks,
Dave
PS Did I mention you guys are awesome? Ok, there it is.
Ok, here's what I found out:
(there's actually 5)
Resistor #1: Measuring from the outer legs to the inner, 45mVDC, outer leg to outer leg, 96mVDC
#2 from outer to outer 1.25, inner to outer .64
#3 0V!
#4 6V outer and inner
#5 Um... Ok, sit down so your *** doesn't come off when you start laughing... I slipped with the probe and shorted out on a bridge wire, which exploded. After removing the power board & fet sink, I repaired the bridge - but didn't spot that a teeeeny bit of solder shorted to another connection, which fried a tiny transistor. Fortunately, the face didn't explode, so I was able to read the numbers and it looks like I can order 20 for $2, so at least now I can blow up another 19 if I'm so inclined...
So... Hopefully you guys won't have given up hope on me when I get that xisitor in so I can continue my "break it REAL GOOD then fix it" home 'lectronics repair course.
Ahhhh $h!t..!
(there's actually 5)
Resistor #1: Measuring from the outer legs to the inner, 45mVDC, outer leg to outer leg, 96mVDC
#2 from outer to outer 1.25, inner to outer .64
#3 0V!
#4 6V outer and inner
#5 Um... Ok, sit down so your *** doesn't come off when you start laughing... I slipped with the probe and shorted out on a bridge wire, which exploded. After removing the power board & fet sink, I repaired the bridge - but didn't spot that a teeeeny bit of solder shorted to another connection, which fried a tiny transistor. Fortunately, the face didn't explode, so I was able to read the numbers and it looks like I can order 20 for $2, so at least now I can blow up another 19 if I'm so inclined...
So... Hopefully you guys won't have given up hope on me when I get that xisitor in so I can continue my "break it REAL GOOD then fix it" home 'lectronics repair course.
Ahhhh $h!t..!
OK, I apologize, this is way off-topic..... but...
Dnarby,
A long time ago you made a post regarding the Sharp QA-2500 and making your own power supply adapter using a PC power supply. I think since then you've sold your setup on Ebay, but I would LOVE for you to share some more info on exactly what you did cuz I've had a QA-2500 sitting at my house for many months that I haven't been able to test because no power adapter, however I have many PC power supplies that are just waiting to be hacked to run my QA-2500
Dnarby,
A long time ago you made a post regarding the Sharp QA-2500 and making your own power supply adapter using a PC power supply. I think since then you've sold your setup on Ebay, but I would LOVE for you to share some more info on exactly what you did cuz I've had a QA-2500 sitting at my house for many months that I haven't been able to test because no power adapter, however I have many PC power supplies that are just waiting to be hacked to run my QA-2500
Sure. I couldn't find a plug to fit the 2500, so first I made one.
Put a piece of tape over the holes where the power supply plugs in. Get some stiff wire (4 pieces 3 or 4 inches long) that fit snugly into the holes on the PS input, and push them through the tape. Note how far they go in. Wrap the wire w/ electrical tape to that point. Push them back through.
Take a 1" or so piece of tubing, plastic, rubber or otherwise, and put it over the wires. The Tape should be wide enough to easily cover the hole in the tubing, and the tubing should fit fairly closely to the wires.
Now mix up a bit of 5 minute epoxy, pour it in, and wait 5 minutes. Pull out your DIY plug, take off the tape. Presto, custom made plug for a 2500.
Next take a computer PS and plug it in. An older PS is just fine, the panel only draws about 45 watts. Check and double check all the voltages, because if you reverse the polarity you will fry your panel. Mark on the wires what the voltages are.
Wire the power supply to your DIY plug according to the pinouts according to the ZIP file attached here. Plug in the PS and check the voltages on your plug. They should match the voltages on the JPG of the PS and the scanned page from the manual. Again, check and double check.
Take a deep breath, plug it in, cross your fingers, hit the switch. Tada!
There's also the pinouts to the video cable in the ZIP in case you need to make/have made one of those.
Enjoy the panel as it's way better than regular TV IMO... But let me know when you get sick of looking at washed out dim pixels and your wife complaining about an OHP on the wall - then I'll give you a good deal on a nice, better than HDTV capable, 30,000 : 1 contrast ratio CRT projector, which is what I'm running now. Even DLPs are just starting to approach CRTs, and the DLPs that are close (but still inferior) cost about 8 times as much as a CRT and are more expensive to run over time. Then your wife can complain about a beastly CRT on the wall - until she realizes the virtues of watching her chick shows on a 12' screen in HDTV. It only took mine about a week to get there.
To you guys who are helping me w/my reciever, I've got the xistors ordered, hopefully you'll still be around when they get here.
Put a piece of tape over the holes where the power supply plugs in. Get some stiff wire (4 pieces 3 or 4 inches long) that fit snugly into the holes on the PS input, and push them through the tape. Note how far they go in. Wrap the wire w/ electrical tape to that point. Push them back through.
Take a 1" or so piece of tubing, plastic, rubber or otherwise, and put it over the wires. The Tape should be wide enough to easily cover the hole in the tubing, and the tubing should fit fairly closely to the wires.
Now mix up a bit of 5 minute epoxy, pour it in, and wait 5 minutes. Pull out your DIY plug, take off the tape. Presto, custom made plug for a 2500.
Next take a computer PS and plug it in. An older PS is just fine, the panel only draws about 45 watts. Check and double check all the voltages, because if you reverse the polarity you will fry your panel. Mark on the wires what the voltages are.
Wire the power supply to your DIY plug according to the pinouts according to the ZIP file attached here. Plug in the PS and check the voltages on your plug. They should match the voltages on the JPG of the PS and the scanned page from the manual. Again, check and double check.
Take a deep breath, plug it in, cross your fingers, hit the switch. Tada!
There's also the pinouts to the video cable in the ZIP in case you need to make/have made one of those.
Enjoy the panel as it's way better than regular TV IMO... But let me know when you get sick of looking at washed out dim pixels and your wife complaining about an OHP on the wall - then I'll give you a good deal on a nice, better than HDTV capable, 30,000 : 1 contrast ratio CRT projector, which is what I'm running now. Even DLPs are just starting to approach CRTs, and the DLPs that are close (but still inferior) cost about 8 times as much as a CRT and are more expensive to run over time. Then your wife can complain about a beastly CRT on the wall - until she realizes the virtues of watching her chick shows on a 12' screen in HDTV. It only took mine about a week to get there.
To you guys who are helping me w/my reciever, I've got the xistors ordered, hopefully you'll still be around when they get here.
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