micle
Junior Member
Posts: 57
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Post by micle on Feb 5, 2022 16:55:43 GMT -5
My only luck is that the oscillator broke, I have long wanted to buy an oscilloscope, maybe I will buy it and let you know.
The only question I can ask you now is if you think the 4.54V XDCERR voltage is right, since when the flat cable (CN1405) is disconnected it measures 4.96V.
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micle
Junior Member
Posts: 57
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Post by micle on Feb 5, 2022 17:23:37 GMT -5
Yes, thanks for the manual, page 75, but unfortunately "POWER ON" always appears and freezes.
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Post by mastertech on Feb 5, 2022 18:02:07 GMT -5
Yes, thanks for the manual, page 75, but unfortunately "POWER ON" always appears and freezes. So even holding down both the "ENTER" and "STANDBY" for 5 to 10 seconds or more it still shows "POWER ON"? At what point does power on show up? It should not even be coming on for this procedure. |
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Post by mastertech on Feb 5, 2022 18:11:08 GMT -5
My only luck is that the oscillator broke, I have long wanted to buy an oscilloscope, maybe I will buy it and let you know. The only question I can ask you now is if you think the 4.54V XDCERR voltage is right, since when the flat cable (CN1405) is disconnected it measures 4.96V. If you do not want to spend the money for a scope just replace the crystals. They are not that expensive. If you do decide this, i would also replace the buffer ic after the crystal on ic800. You are not saying where you are testing the XCDERR voltage at. If you are testing at pin 80 of ic3004, then the 5v would be correct even with CN1405 disconnected. The variation in you readings would probably be normal. Protect mode voltage would be close to 0v. |
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micle
Junior Member
Posts: 57
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Post by micle on Feb 6, 2022 6:18:11 GMT -5
Yes, from standby, "POWER ON" lights up as soon as you press "STANDBY" or "MULTI-ZONE ON / OFF", even in conjunction with any other key.
XCDERR test on the same CN1405.
However, the only problem I have ascertained so far on the boards is the lack of 5V both on all HDMI (pin18, JA9000) and USB (pin 1, CN1259) connections.
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Post by mastertech on Feb 6, 2022 11:55:04 GMT -5
However, the only problem I have ascertained so far on the boards is the lack of 5V both on all HDMI (pin18, JA9000) and USB (pin 1, CN1259) connections. Ok, you may have found something. I can see why the USB port may not have power because it must be enabled and without the unit powering up fully it most likely would not be enabled. However, the HDMI out should have 5v as long as the main transformer is powered. And in tracing things back, that same power source also powers a lot of other important things. So lets take a look. I think we should start at the source and work our way forward. On the digital board, look for cn1900. Use pin 4 for ground probe and pin 1 for positive probe and see if you have +13vdc. |
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micle
Junior Member
Posts: 57
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Post by micle on Feb 7, 2022 12:26:10 GMT -5
CN1900 pin 1-4 = +14.6vdc
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Post by mastertech on Feb 7, 2022 13:23:35 GMT -5
Ok, good. Hopefully you have access for the next test while powered.
Same board, locate R1916 and test for +5v on both sides.
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micle
Junior Member
Posts: 57
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Post by micle on Feb 7, 2022 13:32:26 GMT -5
When you are there, can you please check that your oscillator has the output voltage in Vac?
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micle
Junior Member
Posts: 57
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Post by micle on Feb 7, 2022 13:35:36 GMT -5
R1916 = 5.17vdc
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Post by mastertech on Feb 7, 2022 13:53:36 GMT -5
When you are there, can you please check that your oscillator has the output voltage in Vac? Not sure if this post is for me but you cannot test a crystal with a DMM. Unless it has a frequency testing option. |
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Post by mastertech on Feb 7, 2022 13:55:53 GMT -5
Ok, good. Now locate ic9001. It should be near the HDMI out port. Test for voltage on pins 1,3 and 6. |
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micle
Junior Member
Posts: 57
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Post by micle on Feb 7, 2022 15:22:22 GMT -5
Just wanted to know if the oscillator worked or failed, just compare.
IC9001 is hidden in side B, before disassembling the board I double checked the JA9000 connection and pin 18 has 5.16V, maybe I was wrong first to measure, instead the other 4 HDMI have 0V (pin 18).
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micle
Junior Member
Posts: 57
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Post by micle on Feb 7, 2022 17:12:06 GMT -5
I could, if you agree, test IC9751 pin (1,2,7,9,14); i should disassemble, solder 5 wires, reassemble and test.
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Post by mastertech on Feb 7, 2022 17:13:01 GMT -5
Just wanted to know if the oscillator worked or failed, just compare. IC9001 is hidden in side B, before disassembling the board I double checked the JA9000 connection and pin 18 has 5.16V, maybe I was wrong first to measure, instead the other 4 HDMI have 0V (pin 18). The HDMI inputs will not have the +5v. HDMI inputs receive +5v from source devices. As far as testing for AC on a crystal with a regular DMM, the short answer is, generally, as soon as you try reading the AC voltage when touching it with the probe will cause it to stop oscillating which in turn will just give you a 0vac reading. This is why you need other "devices?" to test a crystal. Just looking for an AC voltage is not relevant. |
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