Shaking the dust off this old thread......there, just like new.
I have been using the dcp501 for quite a while, but a few weeks ago we had a 'power event' (snow) where the power briefly started to go out, but came right back (lights flickered a little, all ups backup power supplies within earshot made a chirp, but did not switch to backup), the dcp501 was playing at the time and got upset at the power event- it said 'overload' on the display. No big deal I thought, just power off and back on, should be fine. But... not fine. Everything acts normal, but no output to speakers (I only use 2, but center and surround outputs also not working). I can use the rca out on the back to get sound from a different amp, and the headphones work.
I took it apart to troubleshoot, but didn't get very far. Here is what I know- there is +/-60vdc coming out of the power supply to the amp board, the input signal to the amp board is there, on the amp board input connector the p-mute and spkr-on are both 4.7v (I assume these are signals to the amp board), and the protect is at 5v (I assume this is a signal from the amp board), it goes through some sequence when powered on (sounds like normal)- 3 lights on amp board light up for a few seconds, relays clicking, then all lights off (I don't remember specifically what the p-mute and skr-on were doing, but they were changing when power on sequence was doing its thing, then remain at 4.7v).
First- any suggestions on what to look for?
Second- for plan B, any suggestions on what would be a good replacement amp to fit in this thing? With 60vdc, maybe the selection is more limited. The heatsink is a slab of aluminum about 4x14x1/4, so maybe I'm also limited to class D (although I'm not opposed to adding a proper heatsink if needed- but may then have to mount the amp where the catv board is now located, which is ok as I can leave the catv board off as it has never been used). As long as sound is same or 'better', I will be happy.
Third (and final, as I am limited to three wishes)- plan C will be to replace the receiver with another (up to $200, I think I paid 100 for the dcp), but really not thrilled at the idea as I suspect I will be disappointed with whatever I get. Is there such a thing as a good sounding receiver (whatever that may mean) under $200?
Thanks.
I have been using the dcp501 for quite a while, but a few weeks ago we had a 'power event' (snow) where the power briefly started to go out, but came right back (lights flickered a little, all ups backup power supplies within earshot made a chirp, but did not switch to backup), the dcp501 was playing at the time and got upset at the power event- it said 'overload' on the display. No big deal I thought, just power off and back on, should be fine. But... not fine. Everything acts normal, but no output to speakers (I only use 2, but center and surround outputs also not working). I can use the rca out on the back to get sound from a different amp, and the headphones work.
I took it apart to troubleshoot, but didn't get very far. Here is what I know- there is +/-60vdc coming out of the power supply to the amp board, the input signal to the amp board is there, on the amp board input connector the p-mute and spkr-on are both 4.7v (I assume these are signals to the amp board), and the protect is at 5v (I assume this is a signal from the amp board), it goes through some sequence when powered on (sounds like normal)- 3 lights on amp board light up for a few seconds, relays clicking, then all lights off (I don't remember specifically what the p-mute and skr-on were doing, but they were changing when power on sequence was doing its thing, then remain at 4.7v).
First- any suggestions on what to look for?
Second- for plan B, any suggestions on what would be a good replacement amp to fit in this thing? With 60vdc, maybe the selection is more limited. The heatsink is a slab of aluminum about 4x14x1/4, so maybe I'm also limited to class D (although I'm not opposed to adding a proper heatsink if needed- but may then have to mount the amp where the catv board is now located, which is ok as I can leave the catv board off as it has never been used). As long as sound is same or 'better', I will be happy.
Third (and final, as I am limited to three wishes)- plan C will be to replace the receiver with another (up to $200, I think I paid 100 for the dcp), but really not thrilled at the idea as I suspect I will be disappointed with whatever I get. Is there such a thing as a good sounding receiver (whatever that may mean) under $200?
Thanks.
I thought I read that somewhere, but cannot find it again. I can't imagine what good that could do though, as I have audio signal to the amp board input, power to the amp board, both mute and spkr-on inputs are high (and mute pin tested on tripath ic, and is low as required), protect pin is high like normal (so it seems the tripath ic's are not indicating a problem), the speaker relays are clicking on, etc.
Maybe if I can find a 2 channel amp board to fit in this thing, I'll just do that.
Maybe if I can find a 2 channel amp board to fit in this thing, I'll just do that.
no output
CURTVM: Believe me, that seems too simple, but it works. Where I live we quite often get power glitches and/or outages and this procedure works every time to get output back. I found it! I keep it in my owners manual. Somebody years ago got to Motorola and they gave him this 'master reset' procedure:
1. put the unit in dvd mode.
2. power off using the button on the front of the unit (do not use the remote)
3. hold down the setup button and the 'down' button at the same time
4. while holding those buttons, press the power button on the unit
5. release all three buttons at the same time
unit should power up in the FM mode and be reset. Motorola says it it doesn't come up in the FM mode, try again.
You should give it a try, got nothing to lose!
CURTVM: Believe me, that seems too simple, but it works. Where I live we quite often get power glitches and/or outages and this procedure works every time to get output back. I found it! I keep it in my owners manual. Somebody years ago got to Motorola and they gave him this 'master reset' procedure:
1. put the unit in dvd mode.
2. power off using the button on the front of the unit (do not use the remote)
3. hold down the setup button and the 'down' button at the same time
4. while holding those buttons, press the power button on the unit
5. release all three buttons at the same time
unit should power up in the FM mode and be reset. Motorola says it it doesn't come up in the FM mode, try again.
You should give it a try, got nothing to lose!
Well, plan C was put in motion- I made a low offer on a 'medium' quality AV Receiver that needs fixing (but is an easy fix- don't even have to open it)
but...
it was bugging me that my receiver is a simple fix away from working again. So, since no schematic (but boards are well labeled), I found the ta3020 datasheet, looked it over a few times and realized I may have made a mistake in checking the power supply voltages. There are VPP +60, VNN -60, but also a VN10 which is VNN+10 - when I checked voltages I was happy to see +/-60v but I didn't realize one of those wires should have been -50v (-60 + 10). So I make my way back to the power supply (buried at the bottom) and discover my error (VN10 measured -60v). To supply the VN10, an LM2575HV simple switcher was used, and it turns out the catch diode (1N5819) was shorted. I don't have any 1A schottky diodes, and I didn't want to order/wait for a 40cent diode so I found a ups backup in the recycle pile I have access to, found a 1N5819 inside, replaced the bad one in my power supply and am back in business.
I sort of still hope my offer is accepted on the other receiver as I would like to hear how it compares to what I have (tripath vs 'discreet amplifier').
but...
it was bugging me that my receiver is a simple fix away from working again. So, since no schematic (but boards are well labeled), I found the ta3020 datasheet, looked it over a few times and realized I may have made a mistake in checking the power supply voltages. There are VPP +60, VNN -60, but also a VN10 which is VNN+10 - when I checked voltages I was happy to see +/-60v but I didn't realize one of those wires should have been -50v (-60 + 10). So I make my way back to the power supply (buried at the bottom) and discover my error (VN10 measured -60v). To supply the VN10, an LM2575HV simple switcher was used, and it turns out the catch diode (1N5819) was shorted. I don't have any 1A schottky diodes, and I didn't want to order/wait for a 40cent diode so I found a ups backup in the recycle pile I have access to, found a 1N5819 inside, replaced the bad one in my power supply and am back in business.
I sort of still hope my offer is accepted on the other receiver as I would like to hear how it compares to what I have (tripath vs 'discreet amplifier').
Not sure if anyone is still watching this thread or not ... but I'll contribute anyway! 
I have the amp installed in my HT setup running off my NAD receiver preamp outputs. I am getting a terrible turn-on and turn-off pop with running the 3 enable connections directly to the PS board. I was switching the amp on/off using the NAD 120V switched outlet. And I don't want to monkey around with a physical switch as I use a remote on my HT setup.
My NAD has a 12VDC TRIGGER output. I wired up a 12VDC automotive relay between the PS 5VDC (COM) and the enable pins on the amp board (NO). I then wired the coil to a mono 1/8" jack on the back of the chassis. The amp AC stays plugged in all the time and now the NAD controls the turn-on and turn-off via the TRIGGER out.
NO MORE POPS!
I have the amp installed in my HT setup running off my NAD receiver preamp outputs. I am getting a terrible turn-on and turn-off pop with running the 3 enable connections directly to the PS board. I was switching the amp on/off using the NAD 120V switched outlet. And I don't want to monkey around with a physical switch as I use a remote on my HT setup.
My NAD has a 12VDC TRIGGER output. I wired up a 12VDC automotive relay between the PS 5VDC (COM) and the enable pins on the amp board (NO). I then wired the coil to a mono 1/8" jack on the back of the chassis. The amp AC stays plugged in all the time and now the NAD controls the turn-on and turn-off via the TRIGGER out.
NO MORE POPS!