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Post by Deleted on Nov 13, 2015 8:27:28 GMT -5
I have a focusboard with this sparking damage.   I have the idea that a high voltage spark somehow hit this board? I measured the mosfets and they seem ok. Also the Caps seem ok. So my guess is repairing the damaged routes could be the only thing needed? Am I right in my opinion? Thanks! |
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Post by hulio on Nov 13, 2015 14:17:49 GMT -5
Ouch....that hurts...
You should check the safety resistors too ( SR1 and SR2 ). Look for bended pins on the connector, that's a bit melted.
If this was happened in one of your projectors, you should search the reason for that arching first.
On the other hand, if i was you, with so many spares, i wouldn't bother repairing the board.
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Post by Deleted on Nov 13, 2015 18:00:39 GMT -5
Hi I got this boardthis way. It might be that someone tried to remove the board while the Barco was on? Or perhaps a spark from the hv lead arked to the focusboard. The hv lead does run on the focus side. You are right that I best use this board for spare parts if another focus board dies. The pins are still ok but there is a hole in the board material. Repair will allways be visible.
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Post by barclay66 on Nov 16, 2015 7:59:52 GMT -5
Hi,
This doesn't look like HV spark damage where only small traces can burn and you mostly see small burning dots over the place (arcs with high voltage but low current). It looks more like an overcurrent event where the vias are burnt away at the location with the smallest diameter because they can't support the amount of current. Maybe someone tried to mount the board at the wrong location and found out using the magic smoke indicator...
Regards,
barclay66
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Post by Deleted on Nov 16, 2015 8:44:28 GMT -5
Hi Barclay. Thanks! I was looking for that kind of knowledge. Could very well be that it was mounted at the location of the controller the astig or the convergence. They all have the same type of connectors.
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Post by barclay66 on Nov 16, 2015 8:49:47 GMT -5
Hi,
You're welcome. I wouldn't try to repair this board. The PCB material has a large damaged area that has to be drilled/cut away completely. Otherwise You may have leakage currents where there shouldn't be. And the connector will have to be replaced as its contacts may be burnt and the plastic may be deformed as well. I would use the board as a parts donor only. But verify each part before mounting it somewhere else...
Regards,
barclay66
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Post by Deleted on Nov 17, 2015 2:59:07 GMT -5
You are right the carbonised material will have conductance. The connector and plastic are still good. Might try to remove the burn. The parts all seem good.
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Post by Deleted on Nov 17, 2015 11:30:21 GMT -5
Ok I found the case that did this. And decided to take it apart. That revealed a trail of probable glycol (it is still wet) comming from the tube and probable dripping on the focusboard connector. They had mysteriously more focusboard fails. I think I know why   |
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Post by Deleted on Nov 24, 2015 9:21:54 GMT -5
I still would like to simple be able to use this board. I am thinking is there not some kind of filling material when I remove all black stuff? Something like woodfill? The connector is still usable. Rerouting is easy with wires.   |
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Post by stridsvognen on Nov 24, 2015 11:37:16 GMT -5
Normaly in cases like that the connector will keep shorting, unless you dig out most of the plastic where its melted, and fill it with something else.
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Post by gjaky on Nov 24, 2015 14:01:03 GMT -5
Normaly in cases like that the connector will keep shorting, unless you dig out most of the plastic where its melted, and fill it with something else. +1 But you don't even have to fill the holes. remove the connector by clipping the leads one by one, then you can remove the remains of the legs from the PCB with a simple solder gun. I bet it is easy to find a new connector from common parts suppliers. Also remove all places where the PCB burnt (eg with a dremel), then recover the missing traces with flying wires. job done (assuming the focus is board working  ) Oh, and make sure the counterpart of this connector is intact on the motherboard too. |
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Post by Deleted on Nov 24, 2015 18:33:06 GMT -5
Yes thanks I was thinking about that. I will remove the complete connector and remove all black pcb. So not filling the holes. Ok. But it becomes less urgent as I exchanged a smps with a focusboard from Hulio. I was missing 3 focusboards as the former owner had 3 of them burn this way and never found out about the glycol leak. With one extra focus board I can start selling one or two complete 919's  I hate it if these wonderfull projectors would go to waste. |
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Post by Casethecorvetteman on Nov 25, 2015 3:39:18 GMT -5
I wouldnt do that, if you dont get the connector perfectly where it should be, count on bent pins.
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I hate it if these wonderfull projectors would go to waste.
