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Post by tokejo on Feb 14, 2014 17:58:24 GMT -5
Time to start on another receiver.
When you power it on, it displays the volume briefly before shutting down.
(I need to hook some speakers and a source up to the other AVR, it powers on and stays on)
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Post by mastertech on Feb 14, 2014 18:58:14 GMT -5
If shutting down then probably good idea to just go right to those outputs and give them a quick test.
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Post by tokejo on Feb 14, 2014 19:17:22 GMT -5
Ok, I'll take a look some time tomorrow and post results.
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Post by tokejo on Feb 15, 2014 19:00:57 GMT -5
Front Left channel, the two larger transistors were bad. I clipped the legs and took them out, plugged it in and it powered on and stayed on. Which other components should I take a look at? ![]()  |
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Post by mastertech on Feb 15, 2014 20:35:50 GMT -5
R424 and R425, .47 ohm. You will have to lift 1 leg on one of these to test both since they are parallel.
R430 and R431, .47 ohm. " Same as above "
ZD402 and ZD403
D403 and D404
Q409 and Q412
R415 and R439, 100 ohm.
That should do it hopefully.
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Post by tokejo on Feb 15, 2014 21:04:35 GMT -5
Fortunately it's a lot easier to get to things in this receiver than the Onkyo, but I was shocked at the difference in heatsinks. The Onkyo was a solid block with chunky fins, this Pioneer is probably less than half the weight and looks cheap.
I'll hopefully have some time tomorrow to get to those components, and test out the issue with the 2nd one.
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Post by tokejo on Feb 16, 2014 14:33:40 GMT -5
Q440 and Q446 were the two transistors that were bad. The components you listed were all good, but those were on the SL channel, not the FL channel that Q440/Q446 were on, so I measured their counterparts one channel over.
R545 is bad, reads OL (R415 read 99.0)
R554/R555 at least one is bad, the two read OL (R424/R425 read 0.3 ohms)
Those are the only parts that differed significantly from the other channel.
Here are the other values, SL channel listed first
ZD402 - 16.97 one way, 1.31 the other
ZD403 - 1.27/17.23
D403 - OL/832
D404 - 828/OL
Q409 - OL/840/818 - 925/1338/OL
Q412 - OL/940/930 - 1507/1997/OL
R415 - 99.0 Ohms
R439 - 99.6 Ohms
R430/R431 - 0.4 Ohms
FL Channel
ZD411 - 16.90/1.10
ZD412 - 1.45/17.67
D421 - OL/831
D422 - 829/OL
Q445 - OL/807/809 - 915/1287/OL
Q446 - OL/938/929 - 1513/OL/OL
R545 - OL
R569 - 99.5 Ohms
R561/R562 - 0.6 Ohms
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Post by tokejo on Feb 16, 2014 14:47:53 GMT -5
I didn't lift a leg, I figured if one was bad I would just figure out which was bad once I order parts and start the repair.
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Post by mastertech on Feb 16, 2014 14:52:08 GMT -5
That's odd, the schematic shows the opposite. My numbers were correct for the FL on the schematic. Are you sure it is the FL that is blown?
If you are getting OL on R554/R555 while still in place then they are both bad.
You still have to lift 1 leg of R561/R562 to test properly but I would recommend to replace them anyways since they were subjected to stress.
Yes, R545 is also bad.
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Post by tokejo on Feb 16, 2014 15:03:44 GMT -5
SL is the Left most channel on the board, then FL. Attachments:
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Post by tokejo on Feb 16, 2014 15:04:08 GMT -5
One last pic Attachments:
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Post by tokejo on Feb 16, 2014 15:07:00 GMT -5
Two transistors and 5 resistors. Not too hard to replace. I've found the transistors already at DigiKey.
What are the specs for the resistors?
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Post by mastertech on Feb 16, 2014 15:23:23 GMT -5
Funny enough, the manual does not give me the wattage of these resistors. So you will have to choose wattage based on what is in there now. The ohm ratings were posted above. Let me know if you need help in this.
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Post by tokejo on Feb 16, 2014 15:27:44 GMT -5
Being partially colorblind, I'll have to get my wife involved, but I should be able to sort them out.
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Post by mastertech on Feb 16, 2014 15:42:57 GMT -5
It's not the color you need to see. You already have the ohm rating. It is the size that determines the wattage.
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