I have a RF P1000-1bd in the shop.
It powers up fine, but no output. I did the usual and checked the power supply transistors and none of the 4 were bad, BUT there was a bad 6.8v zener bad. (big burn dot in the center). Replaced it and all of the supplies are good.
I still have no output, I do not have any drive coming into the drive IC U2000 and U2002, in fact pin 2 of U2000 is 4.81 vdc, which cause the IC to conduct very hard.
Question is, I assume the drive should be on Toggle A and Toggle B. And I do have BD input (clean audio).
The BD diagram I am working with is from a 2500BD amp. which is close, but if the right one is out there, would be appreciated.
It powers up fine, but no output. I did the usual and checked the power supply transistors and none of the 4 were bad, BUT there was a bad 6.8v zener bad. (big burn dot in the center). Replaced it and all of the supplies are good.
I still have no output, I do not have any drive coming into the drive IC U2000 and U2002, in fact pin 2 of U2000 is 4.81 vdc, which cause the IC to conduct very hard.
Question is, I assume the drive should be on Toggle A and Toggle B. And I do have BD input (clean audio).
The BD diagram I am working with is from a 2500BD amp. which is close, but if the right one is out there, would be appreciated.
Well, I replaced both of the 5110, thinking the same. U2000 gets very hot and draws down the supply (10.1 ) to 3.81v. I lift Pin 7 of the 5110, and the supply is returned to normal. I thought the drive transformer was the cause, so I remove it, and the supply still stayed at 10.1 v.
I ohmed the transformer out, it reads .4 ohms, but so does the other one.
The fact the Pin 2 is high (4.81v), and Pin 4 is low, leads me back to the BD board. In the past, when I troubleshot these, I always had drive waveforms. Not in this case however.
Seems like the drive originates from the BD board, to a HC74 IC (which I assume is 74HC74) . The 6 volt supply, that had the burnt zener, feeds that IC.
Am I wrong on my thinking? I have the BD board out now, and I am attempting to figure it out.
And I did see a carrier wave.
I ohmed the transformer out, it reads .4 ohms, but so does the other one.
The fact the Pin 2 is high (4.81v), and Pin 4 is low, leads me back to the BD board. In the past, when I troubleshot these, I always had drive waveforms. Not in this case however.
Seems like the drive originates from the BD board, to a HC74 IC (which I assume is 74HC74) . The 6 volt supply, that had the burnt zener, feeds that IC.
Am I wrong on my thinking? I have the BD board out now, and I am attempting to figure it out.
And I did see a carrier wave.
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You can't have DC driving a transformer. It's like a dead short.
Do you have a square wave on the drains of Q200 and Q201?
Do you have a square wave on the drains of Q200 and Q201?
I removed the bd drive pcb, I powered it up externally to troubleshot it, all I needed was +/- 6 volts. I found that I had oscillation into the clock input of the 74hc74, but nothing coming out of either output. Replaced the 74hc and it was fixed.
Please someone!! I have a p1000bd1 and under the big coil in the middle is what I'm calling a block capacitor that is fried and I can't tell what number is on it, what do I put in there for a replacement? The number next to it on the board is- th1002
Please don't post in a repair thread that was started by someone else unless you are trying to offer assistance to the original poster.
Start a new thread.
Start a new thread.
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