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Post by mastertech on Jan 31, 2022 16:17:55 GMT -5
Ok, see if you can get me the voltages on the following pins of ic3004 with power on only. I do not need tested in standby.
Negative probe on chassis and meter set at DC voltage.
Pins-
8:___ 78:___
17:___ 80:___
18:___ 81:___
19:___ 82:___
57:___ 83:___
58:___ 84:___
65:___ 87:___
70:___
71:___
72:___
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micle
Junior Member
Posts: 57
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Post by micle on Feb 1, 2022 12:46:19 GMT -5
Negative probe on chassis and meter set at DC voltage. Pins- (whit posistor) 8:___4.83 78:___0 17:___4.88 80:___4.54 18:___4.88 81:___0 19:___4.88 82:___0 57:___4.86 83:___4.65 58:___4.86 84:___4.86 65:___2.06 87:___4.86 70:___4.86 71:___4.90 72:___0.67 When I tested pin 72 it went into standby (one click) flashing the ipod led. Then when I turned the receiver back on, pin 72 measured 0.75 V, while the ipod led didn't light up anymore. I attach if I can image of the IC3004 with a strange white spot.  |
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Post by mastertech on Feb 1, 2022 14:18:30 GMT -5
Everything looks fine except pins 65 and 72. I noticed that voltage on 65 a while ago when you tested CN55 but wanted to wait until we had an answer on pin 72. So I guess we need to go back there and finish what we were doing.
Now last time, I wanted you to remove R3232 but you were reluctant to do so. The reason is, the voltage on pin 72 is being affected by something and there are 3 things as possibilities, ic800, ic3004 and something else. So we need to separate these possibilities to find out which is affecting the voltage. Removing R3232 is 1 option or disconnecting the incoming line from ic800. So on connector CP3001, pin 20 you could try removing the wire from the connector, or cut the wire, or remove R1414 on the digital board. Your choice. But I would rather leave R3232 in place for now and disconnect line to ic800.
When disconnected, recheck voltage on pin 72 of ic3004, power on only and 1 test with posistor connected and 1 test with it disconnected and give me those 2 voltages.
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micle
Junior Member
Posts: 57
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Post by micle on Feb 1, 2022 16:51:24 GMT -5
I inserted some cellophane between the flat (pin 20 only) and the connection, circuit interrupted!
Pin 72 with posistor 0.068V.
Without posistor 3.52V and the central blue led is flashing again.
Retried several times, the same thing always happens stably: with posistor it stops as the first part, whitout posistor flashes blue led like the second part.
The IC3004 seems to require an input above 2.2V to not freeze.
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micle
Junior Member
Posts: 57
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Post by micle on Feb 1, 2022 17:04:59 GMT -5
I should make a correction, I don't know if it matters, just to put it in standby you have to press the button for 10 seconds because the system is blocked, instead to turn it on with the same button it starts immediately without waiting 10 seconds, but then it freezes.
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Post by mastertech on Feb 1, 2022 17:34:32 GMT -5
instead to turn it on with the same button it starts immediately without waiting 10 seconds, but then it freezes. Is this something different or was it always this way? |
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micle
Junior Member
Posts: 57
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Post by micle on Feb 1, 2022 17:41:15 GMT -5
I think it has several changes, now it behaves like this.
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Post by mastertech on Feb 1, 2022 18:00:24 GMT -5
Do you have a 300 ohm and 5 ohm resistor?
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micle
Junior Member
Posts: 57
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Post by micle on Feb 2, 2022 2:17:15 GMT -5
No, I only have variable resistance, but I can get it.
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Post by mastertech on Feb 2, 2022 10:45:08 GMT -5
Well you can try the trim pot but I just do not care for it in this circumstance because of possible fluctuations in value. But you can give it a try.
So you need to disconnect the posistor and connect the pot to the 2 pins on the board. From what I have read by someone that tested a new posistor the resistance at room temp should be around 306 ohms so set your pot as close to that as possible. Disconnect CN55 when setting the pot value and then reconnect it after you are done. Also make sure you leave your cellophane in place on pin 20 of CP3001. Then try turning on receiver normally and see what happens.
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micle
Junior Member
Posts: 57
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Post by micle on Feb 2, 2022 13:41:25 GMT -5
I had already tried, reaction as if the original posistor inserted, minimum voltage variation on CN55 pin 5 = 0.079 V.
I had also tried to vary the resistance, in fact after a certain value both increasing and decreasing the blue led flashed.
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micle
Junior Member
Posts: 57
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Post by micle on Feb 2, 2022 13:49:51 GMT -5
If there is anyone practical who has an identical and functioning receiver can tell us what the right voltages are, we will be very grateful.
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Post by mastertech on Feb 2, 2022 13:57:23 GMT -5
I had already tried, reaction as if the original posistor inserted, minimum voltage variation on CN55 pin 5 = 0.079 V. I had also tried to vary the resistance, in fact after a certain value both increasing and decreasing the blue led flashed. You already tried this with the cellophane in place on pin 20 of CP3001? |
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micle
Junior Member
Posts: 57
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Post by micle on Feb 2, 2022 14:07:59 GMT -5
Yes
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Post by mastertech on Feb 2, 2022 14:46:27 GMT -5
I have a couple Pioneers here and I just looked over the schematics. They both use similar posistors but the circuit connecting it is different. Now it is easy to see that when in normal condition that pin should be at 0v. No question, at least on these units I have here. Now I did not actually test them cause I do not have the time but the circuit is very clear.
And I also looked at the ACDET line on these and they both indicate it should be 5v. However, I did not actually test it but the schematic states 5v and the circuit on those look the same as yours.
So, the only way to make sure your pin 72 is 0v would be to remove R3232 and I would also remove C3084 just to be sure that cap is not shorted and causing a problem.
Then I would see if the unit powers up properly. If it does not then that is not the problem.
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