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Post by mastertech on Dec 5, 2016 22:02:04 GMT -5
Would require the removal of R160,R161,TR119,TR120,C127,C128.
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nashou
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Post by nashou on Dec 5, 2016 22:09:09 GMT -5
Would require the removal of R160,R161,TR119,TR120,C127,C128. One more thing. would any AC on either of the lines cause this issue? you mentioned Current for the servo amp so I decided to measure the current there from the + and - sides and at the B line. The + has less current by 1 mA and also it has AC current on it while the - line has no AC current or voltage. the AC voltage fluctuates up and down quickly I see numbers from 35 to 12 to 4 to 0 them cycles again very fast , while the - line is steady at 0 . What can cause this? it must be from the main amp board right? nashou |
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nashou
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Post by nashou on Dec 5, 2016 22:29:17 GMT -5
Checked the voltage from the main board with the EQ board disconnected. I get about 8 mA DC on the - line and only 5 mA on the + line and 0 AC current on - line
but 3.8mA on the + line.
but the voltages in DC are fine on both but i get that fluctuating AC on the + line not on the - Line.
Athansios
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Post by mastertech on Dec 6, 2016 11:46:53 GMT -5
This is an instance where an external power supply would be helpful. I cannot tell you if that AC is a problem or not. But I surely would not just overlook it since power supplies are very picky with stray AC on DC lines especially in newer devices.
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nashou
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Post by nashou on Dec 6, 2016 11:56:22 GMT -5
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Post by mastertech on Dec 6, 2016 12:22:41 GMT -5
Have you checked the output of that external supply for any AC?
Disconnect the B1+ at the board. Then measure the B1- at the board and set your external the complete opposite in voltage and same as in amps and connect it to the board where you disconnected the internal supply.
Use your DMM to set the external output so it is same as measured on opposite supply.
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nashou
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Post by nashou on Dec 6, 2016 12:30:12 GMT -5
Have you checked the output of that external supply for any AC? Disconnect the B1+ at the board. Then measure the B1- at the board and set your external the complete opposite in voltage and same as in amps and connect it to the board where you disconnected the internal supply. I have not tested if it has any AC on it but will. Here is a manual that look close to my unit. it looks like a newer unit. bkpmedia.s3.amazonaws.com/downloads/manuals/en-us/1710A_manual.pdfOk I think I got it. I think I can actually use this to supply both negative and positive. It looks like I can connect the negative to the Negative on the board then the positive to positive and maybe Ground to chassis? But i'll just connect the positive to outboard supply and negative to Yamaha supply . now should I connect outboard GND to Yamaha Chassis? Nashou |
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Post by mastertech on Dec 6, 2016 12:32:29 GMT -5
yes
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nashou
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Post by nashou on Dec 6, 2016 12:47:45 GMT -5
Ok, wierd. the board with the + not connected but the Neg connected its showing a negative on the + side even though we are not connected there.
Just over -1 volt. is that suppose to be there cause of other parts connected to it?
I'm at about -25.3 it will go up as it warms up.
So I'll set the + on the HP to 25.35
Should I measure Current too with my DMM on the Negative supply then tri to match the positive side?
Nashou
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Post by mastertech on Dec 6, 2016 12:57:53 GMT -5
Sure, why not.
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nashou
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Post by nashou on Dec 6, 2016 12:59:36 GMT -5
Ok Not sure how to hook it up.
To get my meter to show voltage from the red output(+) of my HP supply I need to connect the black probe to
the Black output (-) . So does that mean I need to connect the black to the Chassis? doesnt sound right. Also
I dont think the current setting works properly on the HP .
the Amp supply for Neg shows me about 3,8 mA DC but the positive from the
HP positive shows only 2.87 mA.
Come to think of it it seems the same as fromt he readings on the Yamaha DC PS !
I wonder now if its my meter?
Nashou
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Post by mastertech on Dec 6, 2016 13:02:42 GMT -5
?
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nashou
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Post by nashou on Dec 6, 2016 13:10:02 GMT -5
To get voltage reading on my meter i need to connect the positive probe to the positive jack on the
power supply and the negative probe to the negative jack on the power supply. I thought
I had to connect the negative probe to the gnd of the supply?
So do i need to connect the Negative or black jack of PS to a ground on the board somewhere?
its confusing .
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Post by mastertech on Dec 6, 2016 13:21:53 GMT -5
The ? meant I don't know. The center should be gnd unless someone has the + and gnd jumper connected. Does that cover come off around those 3 terminals to see behind there if they are jumpered?
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nashou
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Post by nashou on Dec 6, 2016 13:29:05 GMT -5
The ? meant I don't know. The center should be gnd unless someone has the + and gnd jumper connected. Does that cover come off around those 3 terminals to see behind there if they are jumpered? I don't think so. But when I look for any AC i see it if I connect one Probe to GND and one to either of the + or - terminal. Its 63 VAC. ? I wonder if this is faulty . it was 45 bucks . I had success using it to test Zener voltages and regular diodes etc. Did you look at the other manual? Looks like a new model. I can't find the 1611 manual online anywhere.  |
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