nashou
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Post by nashou on Mar 26, 2017 21:49:09 GMT -5
If you switch your meter to DC voltage and neg lead on xformer pin 8 and pos probe on D927, pin 2 what do you get? 5.19 |
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Post by mastertech on Mar 26, 2017 21:57:05 GMT -5
Try pos probe on other 2 pins of D927 leaving meter on DC.
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nashou
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Post by nashou on Mar 26, 2017 22:03:45 GMT -5
0 volts
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nashou
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Post by nashou on Mar 26, 2017 22:04:53 GMT -5
Those other parts are still out right?
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Post by mastertech on Mar 26, 2017 22:09:03 GMT -5
Right. Change C969 back to the original 35uf and DMM on DC, neg probe on xformer pin 5 and pos probe on D908 cathode.
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nashou
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Post by nashou on Mar 26, 2017 22:23:02 GMT -5
Right. Change C969 back to the original 35uf and DMM on DC, neg probe on xformer pin 5 and pos probe on D908 cathode. still 3.1xx volts |
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Post by mastertech on Mar 26, 2017 22:25:06 GMT -5
I do not understand why your meter is not reading AC voltages on the xformer. Let me think about this a little and check back tomorrow.
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nashou
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Post by nashou on Mar 26, 2017 22:29:46 GMT -5
Yeah I'm done for the night. Last check the one clip from the DC PS touched the heat sink of one double diode and blew my circuit breaker. luckily nothing got damaged on the board. This was after the AC voltage check a few post later.
So I still have the 400,12 and 24 and 5 volt stand by of course.
Nashou
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Post by mastertech on Mar 27, 2017 20:54:49 GMT -5
Well I did a little more investigating and it looks like that line should definitely be app. 15vdc. I would still like to see the AC voltages on those windings. Do you have a different AC meter to test with?
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nashou
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Post by nashou on Mar 28, 2017 9:34:34 GMT -5
Well I did a little more investigating and it looks like that line should definitely be app. 15vdc. I would still like to see the AC voltages on those windings. Do you have a different AC meter to test with? So should I bump up the DC supply to say 14.5vdc . I know that meter works cause I got the 125 VAC on across the N and L pads of the main AC in . But I'll try my other meter. nashou |
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nashou
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Post by nashou on Mar 28, 2017 10:06:18 GMT -5
Ok No AC on those pins but I do have some on pins 1,2 of that Xfmr. Now we still have R991 out and across the empty pads of that SMD resistor i have some ac voltage , not sure it matters but i thought id ad that info.
nashou
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Post by mastertech on Mar 28, 2017 12:08:29 GMT -5
I guess the AC voltage is at to high a frequency for your meter to read. Scope would probably read it. There has to be AC there because you have rectified DC.
Do you have any DC voltage on the cathode of ZD913? Also check cathode of ZD910. And R921,R991,R917 should still be out and R976 should still be lifted and connected to external supply.
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nashou
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Post by nashou on Mar 28, 2017 12:48:10 GMT -5
Yes I have voltages there, 1.6 and 5.6
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nashou
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Post by nashou on Mar 28, 2017 12:49:02 GMT -5
How would I measure using scope?
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nashou
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Post by nashou on Mar 28, 2017 12:51:50 GMT -5
How would I measure using scope? I tried hooking the GND probe to hot GRD C903 and it blew the main fuse F901. So I guess that was wrong  Everything is ok though |
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