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Post by mastertech on Mar 20, 2016 10:33:20 GMT -5
This gnd is not chassis gnd so that will not work. It must be pin 10 on both ic's. Solder a wire on if you do not want to hold probe.
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chad
Junior Member
Posts: 21 
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Post by chad on Mar 20, 2016 11:26:36 GMT -5
I see, ok I re-tested with the neg probe on the 10 pins:
IC1:
1 over .350
2 over .350
3 OL
4 OL
5 OL
6 OL
7 OL
8 OL
9 OL
10 ground
11 0.00
12 over .350
13 over .350
14 over .350
15 over .350
16 over .350
17 over .350
18 over .350
19 over .350
IC2:
1 OL
2 OL
3 OL
4 OL
5 OL
6 over .350
7 over .350
8 OL
9 0.00
10 ground
11 OL
12 OL
13 over .350
14 over .350
15 OL
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Post by mastertech on Mar 20, 2016 11:39:10 GMT -5
I think you had the neg probe on the wrong pin on IC1. Pin 9 should read short, not 11.
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chad
Junior Member
Posts: 21
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Post by chad on Mar 20, 2016 16:04:48 GMT -5
I re-checked, and pin 9 read 0.00. The probe might have moved the 1st time.
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Post by mastertech on Mar 20, 2016 16:18:22 GMT -5
I need you to recheck all pins on that ic1. The pins of both ics should read the same except for the extras and they do not.
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chad
Junior Member
Posts: 21
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Post by chad on Mar 20, 2016 19:33:35 GMT -5
Rechecked both ic's:
IC1:
1 OL
2 OL
3 OL
4 OL
5 OL
6 OL
7 OL
8 OL
9 0.00
10 Ground
11 0.00
12 over .350
13 over .350
14 over .350
15 OL
16 over .350
17 over .350
18 over .350
19 over .350
IC2:
1 OL
2 OL
3 OL
4 OL
5 OL
6 OL
7 OL
8 OL
9 0.00
10 ground
11 0.00
12 over .350
13 over .350
14 over .350
15 OL
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Post by mastertech on Mar 20, 2016 20:32:17 GMT -5
Ok, now I need you to check the voltages on all those pins. Now you will use chassis for ground probe, DMM on DC voltage and give me the readings.
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chad
Junior Member
Posts: 21
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Post by chad on Mar 28, 2016 10:03:40 GMT -5
While attempting the last test, I had 2 shorts; 1 at the jumper wire, and a very loud short at IC1. There's now 2 sets of burn marks, so I think I've caused too much damage to be worth the parts to fix it. I really appreciate your help and time.
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Post by mastertech on Mar 28, 2016 11:38:42 GMT -5
Well at least you got a little experience out of it.
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chad
Junior Member
Posts: 21
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Post by chad on Mar 29, 2016 8:26:48 GMT -5
Yes, true. Maybe next time I will only try tests with the power not plugged in. Thank you again for your time, and I appreciate the experience I got out of it.
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Post by kevint on Sept 24, 2017 13:44:02 GMT -5
Hello, just wondered if I could "Piggyback" onto this thread, as I have pretty much the exact same issue as the OP, and the same Yamaha receiver.
Mine was playing fine, then suddenly shut off, no error codes or anything, as if it just lost all power.
I tried fuse, and nothing, and tried the Reset procedure, main relay would click on and them back off in about .5 seconds.
Then I jumpered the relay across the film cap shown earlier in the thread, in the power supply section, display came on with a code:
DC PROTECT 255H
But nothing else will happen.
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Post by mastertech on Sept 25, 2017 9:49:29 GMT -5
It looks like you might have a blown output.
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Post by kevint on Sept 25, 2017 10:43:42 GMT -5
I think I had a short with the speaker wires, but never saw the normal Error message.
It just shut off.......
Would this even be worth trouble shooting then?
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Post by mastertech on Sept 25, 2017 11:22:55 GMT -5
Well that is a decision that only you can make. I am sure there are others on here that would buy if off of you if you choose not to fix it.
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Post by kevint on Sept 25, 2017 13:37:30 GMT -5
Well that is a decision that only you can make. I am sure there are others on here that would buy if off of you if you choose not to fix it. What would you suspect is the most likely component or components that are damaged? Would this be easy to test with A DMM? I have a good bit of electronics knowledge if it is worthwhile doing for sure! |
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