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Post by kopraish on May 3, 2019 14:04:16 GMT -5
Link for direct download service manual: dox.abv.bg/download?id=56b1ce5f1aHi. I wait yet for parts for my Sony amp, and i buy this Pioneer and i hope we can repair together. When i push power button main relay click, and nothing. I have 9.7v on emitter and 9.7v on base Q1/Q2/Q3/Q4 (final transistors 2SA1302/2SC3281 both channels), collector -52v, of course i have this voltages (9.7v) and on emitter resistors E409/R410. On both sides R309 (220ohm) I have 8.8mV, on scheme they must be 15-16v. Could you help me... Attachments:
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Post by mastertech on May 3, 2019 22:00:26 GMT -5
Do you know the transistor symbols? Your image and post description do not match. On the collector of Q4 you should have around -50 volts and on the collector of Q2 you should have around +50 volts. You say you have -52 volts on collector of something but your image shows 9.7v on both collectors.
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Post by kopraish on May 4, 2019 9:43:20 GMT -5
I am so sorry, my mystake on picture. I upload new one picture. I have 6.6v on B-E at the begining when i turn on amplifier, which ''UP'' to 9.7v after 3-4 seconds, and they are stays stable on 9.7v. Attachments:
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Post by mastertech on May 4, 2019 11:17:55 GMT -5
And? What are on the collectors?
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Post by kopraish on May 4, 2019 14:44:08 GMT -5
+-/52v.
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Post by mastertech on May 4, 2019 18:50:58 GMT -5
Can you disconnect the harness I have indicated with the red arrow and test to see if the 9.7v changes?  |
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Post by kopraish on May 5, 2019 5:27:09 GMT -5
Yes, after remove this connection everything is fine 0V-45V-0V. Output relays click.
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Post by mastertech on May 5, 2019 12:59:44 GMT -5
Can you test for any DC voltage on all pins in the red circle?  |
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Post by kopraish on May 5, 2019 13:36:31 GMT -5
1. 9.14v
2. 10.20v
3 9.18v
4. 9.90v
5.GND
6. 45.1v
7. 9.90v
8. GND
9. 9.90v
10. 9.08v
11. 10.20
12.9.11
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Post by mastertech on May 5, 2019 13:54:26 GMT -5
Check R444 on amp board.
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Post by kopraish on May 5, 2019 14:19:39 GMT -5
R444-Open (5.20mohm) Is it 4.7ohm or 47 ohm?
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Post by kopraish on May 5, 2019 14:39:37 GMT -5
R444 is 4.7ohm. Now amp work, i will repait input switch, but i have main question. Now i see someone is replace R443, What could be the reason for it to be damaged R444/R443?
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Post by mastertech on May 5, 2019 16:50:55 GMT -5
Don't know why. Could be a weak part of the circuit or just susceptible to power surges.
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