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Hulio
Joined: 15 Apr 2006
Posts: 494
Location: Belgium
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| Posted: Tue Jun 21, 2022 2:35 pm Post subject: |
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That's the horizontal linearity control board, and there is no component C7 on it. I think you are confusing it with the electrolytic capacitor C1.
Q1 is the one in your picture, that's a MOSFET transistor and to check it out you have to take it out of the circuit.
From left to right in your picture, the transistor legs are: Gate, Drain, Source. The best way to check it, is to put your multimeter in diode modus.
Black probe to Source and red probe to Drain should give a reading between 0,4V and 0,9V. If 0, open or no reading, the transistor is bad.
Now if you reverse the probes (black probe to Drain and red probe to Source) and the reading is 0, open, or no reading, the transistor is also bad.
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Wed Jun 22, 2022 2:59 am Post subject: |
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| Hulio wrote: | That's the horizontal linearity control board, and there is no component C7 on it. I think you are confusing it with the electrolytic capacitor C1.
Q1 is the one in your picture, that's a MOSFET transistor and to check it out you have to take it out of the circuit.
From left to right in your picture, the transistor legs are: Gate, Drain, Source. The best way to check it, is to put your multimeter in diode modus.
Black probe to Source and red probe to Drain should give a reading between 0,4V and 0,9V. If 0, open or no reading, the transistor is bad.
Now if you reverse the probes (black probe to Drain and red probe to Source) and the reading is 0, open, or no reading, the transistor is also bad. |
OK！
I wonder why the deflection board was burned? first deflection board of C7, then deflection board of 708.... Is it the SMPS board or the focus board or other reasons?
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Wed Jun 22, 2022 3:03 am Post subject: |
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If the cause is not found, even if the deflection board is replaced with a good board, it will burn again.
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Fri Jun 24, 2022 2:32 am Post subject: Barco 708MM “HOLD DOWN EHT” fault |
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The measured value of one triode on the deflection board is different with the other two.[/i]
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3402 Time(s) |
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Fri Jun 24, 2022 2:37 am Post subject: Barco 708MM “HOLD DOWN EHT” fault |
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It's going to be removed and tested
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Hulio
Joined: 15 Apr 2006
Posts: 494
Location: Belgium
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| Posted: Fri Jun 24, 2022 4:46 am Post subject: |
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That's not thyristor C7 but high voltage MOSFET (transistor) Q10.
You can check it the same way as above if you wish, but i doubt it is broken. It is normal to give other reading than Q8 and Q9, as long time the components are not measured out of the circuit.
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Fri Jun 24, 2022 5:07 am Post subject: |
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oh,sorry! C7 means Barco Cine7.
Thanks!
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Fri Jun 24, 2022 5:17 am Post subject: Barco 708MM “HOLD DOWN EHT” fault |
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| Hulio wrote: | That's not thyristor C7 but high voltage MOSFET (transistor) Q10.
You can check it the same way as above if you wish, but i doubt it is broken. It is normal to give other reading than Q8 and Q9, as long time the components are not measured out of the circuit. |
OK, if Q10 is broken, I will replace it. I have bought Q10 and it is on the way，thank you!
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Fri Jul 29, 2022 1:42 pm Post subject: |
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I come back and continue to talk about this C7. after changing some boards, C7 was finally lit, However, it brings a new problem. Using this connection method: pioneer 09fd-hdmi-moone-5bnc-5bnc-c7, the signal source is set to 3, and the displayed image is very dark. It is found that the contrast adjustment of the image is invalid, but the brightness adjustment is normal. I can't find the reason. thank you!
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Fri Jul 29, 2022 1:51 pm Post subject: Barco 708MM “HOLD DOWN EHT” fault |
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The brightness of the image is low. Because the contrast adjustment fails, the contrast of the image cannot be increased to improve the brightness, so it cannot be viewed normally
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Sat Jul 30, 2022 2:41 pm Post subject: |
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I replaced the GBR board of this C7, and the contrast adjustment function returned to normal
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Sat Jul 30, 2022 2:44 pm Post subject: Barco 708MM “HOLD DOWN EHT” fault |
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You can see the words "contrast adjustment" on the GBR board
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Hulio
Joined: 15 Apr 2006
Posts: 494
Location: Belgium
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| Posted: Sat Jul 30, 2022 9:58 pm Post subject: |
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No contrast adjustments on the RGB input board. The text "To contrast mudulation" next to connector J757 means you can connect the optional contrast modulation board R7624845 in there. Something you don't need.
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Sat Jul 30, 2022 11:20 pm Post subject: Barco 708MM “HOLD DOWN EHT” fault |
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| Hulio wrote: | | No contrast adjustments on the RGB input board. The text "To contrast mudulation" next to connector J757 means you can connect the optional contrast modulation board R7624845 in there. Something you don't need. |
You're right！
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bluemoonhu
Joined: 16 Feb 2021
Posts: 259
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| Posted: Sun Jul 31, 2022 12:29 am Post subject: Barco 708MM “HOLD DOWN EHT” fault |
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Can you find the contrast adjustment module or circuit unit in the GBR board?Can it be repaired？
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