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Post by mastertech on Mar 19, 2019 19:12:16 GMT -5
which boards are you calling the driver boards? The ones with the pots on them?
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nashou
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Post by nashou on Mar 19, 2019 19:23:12 GMT -5
which boards are you calling the driver boards? The ones with the pots on them? Yes. I don't think we tried to see DC on speaker outs with outputs still on heat sinks but the driver/amp boards removed. not sure if that is possible or wise. Also , the 3 watters do go to GND and the other ends go to the relay. they are 220 ohm's Also I measured the GND at the speaker out GND . The large cap on that board is 1000uf but I can not see the voltage. I assume its 35 I took more pics will up load now |
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nashou
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Post by nashou on Mar 19, 2019 19:30:17 GMT -5
More pics oh And the Black wire is GND , the one resistor goes to the same pad. Looking at the second pic it looks a little burnt maybe?     |
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nashou
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Post by nashou on Mar 19, 2019 19:48:41 GMT -5
Ok Discovered something just now testing components on the relay board even as cramped as it is and still in the unit. The 1N4003 diode reads .250 in both directions. While on the board.  I think I need to remove one leg to be sure . My parts tester also showed it as bad or unknown part. can you tell where that goes to in the relay? maybe I should measure voltage on either side while powered up, but the other end of the caps are not connected to the relay board now. Athanasios |
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nashou
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Post by nashou on Mar 19, 2019 19:57:24 GMT -5
Ok measured the voltage across the Diode and it was 21-22 VDC.
On the Band side it read 28 and on the other side it slowly dropping from12 vdc to a very very slow drop around 4.24 VDC .
negative probe on common of speaker out.
Might be the culprit ?
nashou
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Post by mastertech on Mar 19, 2019 20:26:50 GMT -5
That diode is most likely a suppression diode across the relay coil. You would have to lift 1 leg to test for sure.
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nashou
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Post by nashou on Mar 19, 2019 20:32:02 GMT -5
That diode is most likely a suppression diode across the relay coil. You would have to lift 1 leg to test for sure. Ok will do. |
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Post by mastertech on Mar 19, 2019 20:32:46 GMT -5
If those 2 3 watt resistors do connect to each speaker line and other side to gnd then they may be the filters to help remove the DC. And if the gnd connection has a problem, even where that black wire connects at its opposite end then they may not remove all of the DC. Check that black wire where it connects to gnd and also resolder those 3 watt resistors and then recheck the DC on the speaker connector.
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Post by mastertech on Mar 19, 2019 20:39:45 GMT -5
Also check these 2 diodes. Lift 1 leg on each and look for even slight leakage. Also may sure to read post above this one.  |
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nashou
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Post by nashou on Mar 19, 2019 20:45:56 GMT -5
If those 2 3 watt resistors do connect to each speaker line and other side to gnd then they may be the filters to help remove the DC. And if the gnd connection has a problem, even where that black wire connects at its opposite end then they may not remove all of the DC. Check that black wire where it connects to gnd and also resolder those 3 watt resistors and then recheck the DC on the speaker connector. Ok will do. And I'll check those two diode 's with my parts tester . But how do you test leakage? I am not sure if my parts tester does that. It basically just tells you what part it is and its characteristics. I'll snap a pic of the display of its test. Also I guess i need to re connect the filtering caps then. correct? Nashou |
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Post by mastertech on Mar 19, 2019 21:07:20 GMT -5
Check for leakage with DMM on diode scale. Should show no flow in 1 direction.
Yes reconnect those caps.
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Post by mastertech on Mar 19, 2019 21:08:07 GMT -5
Lift 1 leg on each diode to test
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nashou
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Post by nashou on Mar 19, 2019 21:11:53 GMT -5
Top diode  bottom Diode  And the Other end of that Black GND wire. Looks solid, pulled on it. I should have reflowed it but did not.  Caps are connected, left the black gate there for now. Will test next. |
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nashou
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Post by nashou on Mar 19, 2019 21:13:29 GMT -5
Just saw your other post, crap did not use DMM  |
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nashou
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Post by nashou on Mar 19, 2019 21:23:03 GMT -5
No Luck, still DC.
Should I go back and use the DMM for the diodes of is the results from my tester ok?
Nashou
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