i have a zr1000 with a power supply issue. amp powers up fine and plays fine at low volume. whey you turn up the volume then it goes into protect. upon futher testing the rail voltage drops on one side only. i have the input set to full range and have 8ohm speakers connected. i checked the power supply fets and the signal to them. Attached photo shows the output from the power supply driver.
SG3525ADW. thought it might be a faulty driver so i replaced it and no change. also changed the timing cap and still no change. any ideas?
SG3525ADW. thought it might be a faulty driver so i replaced it and no change. also changed the timing cap and still no change. any ideas?
Attachments
You have two outputs from U1, Pin 11 and 14. Do they both look similar to the photo you post?
Post a photo of the waveform on pin 5.
Check the values of R6-4.99K ohm, R7-150 ohm and check C3-47uf with an ohmmeter and capacitance meter if available.
I believe C2 is a .0047uf cap. Make sure that C2,C3 and R6 are connected to chassis ground.
Post a photo of the waveform on pin 5.
Check the values of R6-4.99K ohm, R7-150 ohm and check C3-47uf with an ohmmeter and capacitance meter if available.
I believe C2 is a .0047uf cap. Make sure that C2,C3 and R6 are connected to chassis ground.
i have pulled the rectifiers on both sides. wanted to see the waveform with out a load from the amp. i will post the pics soon. the wave form was the same on both. i did change the cap with 4 of .001 in parallel that gave me the wave form that was shown. didnt get a chance to show the wave before i changed the caps.
When you post scope waveforms, you need to include the timebase and vertical amplifier settings. Otherwise, the waveforms are mostly useless.
Can you clarify what you mean by 'the rail voltage drops on one side only'?
Can you clarify what you mean by 'the rail voltage drops on one side only'?
yes Perry i do understand that i should have included those.Was just wanting to show a basic wave that i was getting. I will include everything on the next post. Thank you sir.
this is the sign wave I get off the power supply fets. Gate Sent from my SAMSUNG-SM-G900A using Tapatalk
Please read the oscilloscope page of the car audio site in the sig line below. It's page 73. Pay special attention to the 'best initial settings' section.
If you reduce the 12v power supply voltage to about 11v, the waveform will likely become what you expect ti to be.
If you reduce the 12v power supply voltage to about 11v, the waveform will likely become what you expect ti to be.
Okay. I don't have a adjustable power supply. Still the power supply will not stay on under load. Wish I could video this one. Never seen this before.
Sent from my SAMSUNG-SM-G900A using Tapatalk
Sent from my SAMSUNG-SM-G900A using Tapatalk
Yes, left works well right side is the side that drops. But on the transformer both sides drop. That is checking ac voltage before the rectifier.
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Sent from my SAMSUNG-SM-G900A using Tapatalk
Do you have a sine wave generator (or anything that will allow you to drive a sine wave into the amp)?
I think so. Never used it that way before. It's a bk precision 3011b.? Not sure if that would work.
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Sent from my SAMSUNG-SM-G900A using Tapatalk
OK. Let's try something else. In the channel that's causing the amp to shut down, are all of the emitter resistors with tolerance?
While playing the sign wave on the power supply changes.
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Sent from my SAMSUNG-SM-G900A using Tapatalk
You can get rid of that samsung sig line if you don't want it.
Do the resistors read the same in the other channel? They should be 0.33 ohms but the meter leads sometimes make them read higher.
Do the resistors read the same in the other channel? They should be 0.33 ohms but the meter leads sometimes make them read higher.
I have a second zr1000 here as well. It is now in working condition, so I have something to go on. But I need a schematic with some test points. Was told where to find but forgot where. Old age.....lol
You are never to old to learn!!!
You are never to old to learn!!!
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