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Post by jaredjaric on Jul 22, 2018 12:42:23 GMT -5
HI Guys,
Need help on a new issue of my 909, Hope to hear form Hulio.
after swapping out all the HV parts, eht quad and splitter.I still can not get the crt running. The 17volts seem consistent and no other red leds but the ususal scan fail and some on the h board due mainlyt to no video signal.
Prior to the scan fail, there was a loud pop inside the PJ and i assumed it was a failing quad.
But after three quads and splitters and ehts still no go.
What else is there to cause this?
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Post by Casethecorvetteman on Jul 22, 2018 16:31:15 GMT -5
Its likely to be the vertical or horizontal boards, it is a deflection failure by the sound of it.
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Post by hulio on Jul 22, 2018 16:35:57 GMT -5
Other situations that will generate a scan fail red led (excepting EHT, quad and splitter) are:
1. Some unserviceable fuses on the SMPS are blown (F201, F207).
2. You have a bad CRT (shorted).
So first, try another SMPS module. To check the CRT's, with the projector turned off, disconnect the HV lead of the tube from the splitter (check the tubes one by one) and start the projector. If the scan fail led on the EHT stays off without a CRT connected to the splitter, that tube is bad. Careful, don't disconnect the HV lead of the quad from the splitter.
If you have spare parts, swap the vertical and horizontal boards too, before checking the CRT's.
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Post by mastertech on Jul 22, 2018 16:47:14 GMT -5
What is an "unserviceable fuse"  |
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Post by hulio on Jul 22, 2018 17:04:04 GMT -5
A fuse that is not mounted on a fuse-holder (to be fast checked/changed by the end user), but soldered directly on the PCB.
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Post by mastertech on Jul 22, 2018 17:09:23 GMT -5
LOL. I just thought the "unserviceable" word was funny and not used correctly. I have changed many of those style fuses. Because they are replaceable or serviceable. If either of those fuses are blown then the green leds on the G2 board for those 2 lines would be off, correct? (-9v and +30v) |
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Post by mastertech on Jul 22, 2018 18:54:11 GMT -5
This is a good layout and description of the scan fail circuit and what can cause a scan fail. Scanfail 909.pdf (57.78 KB)  |
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Post by hulio on Jul 22, 2018 21:55:42 GMT -5
If either of those fuses are blown then the green leds on the G2 board for those 2 lines would be off, correct? (-9v and +30v) Yep, according to Barco, when F201 is blown the following leds on G2 board should be off: +CON, 30V, D120 and HDHT. When F207 is blown, led -9V is off. |
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Post by jaredjaric on Jul 24, 2018 10:34:01 GMT -5
Other situations that will generate a scan fail red led (excepting EHT, quad and splitter) are: 1. Some unserviceable fuses on the SMPS are blown (F201, F207). 2. You have a bad CRT (shorted). So first, try another SMPS module. To check the CRT's, with the projector turned off, disconnect the HV lead of the tube from the splitter (check the tubes one by one) and start the projector. If the scan fail led on the EHT stays off without a CRT connected to the splitter, that tube is bad. Careful, don't disconnect the HV lead of the quad from the splitter. If you have spare parts, swap the vertical and horizontal boards too, before checking the CRT's. Thanks guys for the valuable info, the support you guys give makes this hobby so worht it.
Hulio , you were spot on. it was the smps and most probably one of the "unservicable fuse or fuses" were blown, we heard some pops.
Thanks Hulio, more power to you.
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Post by jaredjaric on Jul 24, 2018 10:35:39 GMT -5
This is a good layout and description of the scan fail circuit and what can cause a scan fail. This is very valuable info for me. Thank you very much. |
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Post by jaredjaric on Jul 24, 2018 13:23:13 GMT -5
Other situations that will generate a scan fail red led (excepting EHT, quad and splitter) are: 1. Some unserviceable fuses on the SMPS are blown (F201, F207). 2. You have a bad CRT (shorted). So first, try another SMPS module. To check the CRT's, with the projector turned off, disconnect the HV lead of the tube from the splitter (check the tubes one by one) and start the projector. If the scan fail led on the EHT stays off without a CRT connected to the splitter, that tube is bad. Careful, don't disconnect the HV lead of the quad from the splitter. If you have spare parts, swap the vertical and horizontal boards too, before checking the CRT's. HI agin Hulio and guys, Just wanted to report more on the smps and seeking assistance for repair.
After swapping in a good smps, i decided to swap the standby boards.
On the bad smps , i replaced it with a standby board from the good smps.
The supposed bad smps was now powering up normally w/o scan fail now, and so the real culprit was the stand by module.
Can this be just a case of bad capacitors on the standby board?
how should i go about repairing it,
hope i can get help on minor board repair from the masters.
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Post by mastertech on Jul 24, 2018 19:25:50 GMT -5
The first thing I would test would be fuse (F450) and safety resistors (SR50- 0.1 ohm and SR70- 100 ohm)
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