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Post by mastertech on Apr 23, 2015 20:44:59 GMT -5
Wouldnt that be a laptop power adapter used to recharge it? No, that is usually a much higher voltage. I thought everybody had a box full of wall wart supplies from past devices long thrown away, lol. |
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Post by jbmeyer13 on Apr 23, 2015 20:47:40 GMT -5
Just took a 5v from my lumagen hdq. What next?
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Post by mastertech on Apr 23, 2015 21:03:25 GMT -5
Just took a 5v from my lumagen hdq. What next? We don't want to use a good one in case we damage it. Plus we would probably have to cut the end off of it. Let me see if I can narrow down where the specific part might be. Go back to C9 or C6 and do the test with DMM in ohm scale. Reverse leed test also. |
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Post by jbmeyer13 on Apr 23, 2015 21:25:36 GMT -5
At C6 it reads 256ohm in either direction
At C9 it reads 256ohm in either direction
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Post by mastertech on Apr 23, 2015 21:51:48 GMT -5
Ok, lets try a gamble. Locate D32, D34 and D36. DMM on diode scale and test across legs 1 and 3, also reversing leeds. See if they all read the same. Here is how to tell what legs are 1 and 3: www.vishay.com/docs/85736/mmbd7000.pdf |
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Post by jbmeyer13 on Apr 23, 2015 22:06:06 GMT -5
D32, 34 and 36 have all been removed.
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nashou
Unmoderated Off Topic
Tech in Training.....
Posts: 1,239 
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Post by nashou on Apr 23, 2015 22:09:41 GMT -5
D32, 34 and 36 have all been removed. They do have legs, or pins if that is more comfortable for you.. they are located right up against the blue relays. Nashou |
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Post by mastertech on Apr 23, 2015 22:10:07 GMT -5
D32, 34 and 36 have all been removed. They have tiny legs as can be seen in the datasheet picture. How about D28, D40, D30 and D37? |
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Post by jbmeyer13 on Apr 23, 2015 22:23:24 GMT -5
All read .257 in either direction on pins 1 & 3
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Post by mastertech on Apr 23, 2015 22:29:55 GMT -5
All read .257 in either direction on pins 1 & 3 Is that in diode scale or ohm scale? |
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Post by jbmeyer13 on Apr 24, 2015 5:58:31 GMT -5
All read .257 in either direction on pins 1 & 3 Is that in diode scale or ohm scale? That was done in the diode scale. In ohms they all read 432 in either direction |
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Post by mastertech on Apr 24, 2015 9:48:06 GMT -5
Well there are really only 2 options here to proceed. Either start removing some specific parts until the short goes away, or apply a voltage to the line and look for a component that is getting hot.
Let me know what you would like to do.
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Post by jbmeyer13 on Apr 24, 2015 10:11:46 GMT -5
Well there are really only 2 options here to proceed. Either start removing some specific parts until the short goes away, or apply a voltage to the line and look for a component that is getting hot. Let me know what you would like to do. Well I think the second option is better as there are a number of modifications and/or parts I don't want to mess with. I'll have to try to see if I have another wall wart or pick one up. What will I need to do to adapt the wall wart for this procedure? |
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Post by mastertech on Apr 24, 2015 11:38:47 GMT -5
Ok, then you will need a 5vdc supply, app. 500ma. We don't want to increase voltage cause there are voltage limited ic's on board. The amperage isn't critical but I would think at least the 500ma so as to have enough current to heat up the defective component.
You will be connecting it to TP2 and ground but you will be hooking it up backwards for the neg voltage.
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Post by jbmeyer13 on Apr 24, 2015 12:29:04 GMT -5
Ok, then you will need a 5vdc supply, app. 500ma. We don't want to increase voltage cause there are voltage limited ic's on board. The amperage isn't critical but I would think at least the 500ma so as to have enough current to heat up the defective component. You will be connecting it to TP2 and ground but you will be hooking it up backwards for the neg voltage. I figure an old cell phone charger should work. So TP2 is negative connection and ground is positive in this scenario? |
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