nashou
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Post by nashou on Feb 17, 2017 23:25:36 GMT -5
I get readings across both caps .250 and .780 for each flipping the probes .
I noted earlier that I noticed a lot of corrosion next to that chip including R724,734,721,723 and some of the pins on the 26-30ish side.
How do I know for sure if it's bad?
Nashou
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Post by mastertech on Feb 17, 2017 23:37:03 GMT -5
well it is not putting out any voltage and all the inputs and triggers are correct. The only thing not tested was feedback at pin 31 but if there is no output then there would be no feedback. This ic is the same as ic77 so you can check the output of ic77 and see if you have 1.8v output on pin 6. If you do, you could swap these ic's if you wanted to verify but I would leave out L713 when testing in case something after it caused ic73 to fail.
In fact, I would like you to test with your DMM on diode scale between gnd and the pad of L713 that is "NOT" connected to ic73 and see what the reading is.
Got to go for today so I will check back tomorrow.
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nashou
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Post by nashou on Feb 17, 2017 23:58:39 GMT -5
.368 and .540 diode scale reading.
I used DGN on the PCB and again with the GND pad on q702 and got the same numbers.
nashou
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Post by mastertech on Feb 18, 2017 10:03:24 GMT -5
Well those numbers don't look bad. To bad you didn't have a 3.3v external supply you could inject into that line and see what happens.
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nashou
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Post by nashou on Feb 18, 2017 13:03:38 GMT -5
Well those numbers don't look bad. To bad you didn't have a 3.3v external supply you could inject into that line and see what happens. I have two DC power suplies. no reason I can't just tell be whereto hook up the positive and negative wires. I'll do it later today. nashou |
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Post by mastertech on Feb 18, 2017 13:55:54 GMT -5
I would first set your supply to 3.3v before connecting it. Then connect the pos to the pad of L713 that was "NOT" connected to IC73. Then connect the neg to DGND where ever. I would turn on the supply and not even plug in the receiver yet and see if it holds the 3.3v Then see if any ic's feel hot. It looks like that 3.3v line powers a bunch of ic's, not just the 2 you checked for heat before. So feel around. If nothing seems hot and the 3.3v holds then plug in the receiver and turn it on and see what happens. I will await your results.  |
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nashou
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Post by nashou on Feb 18, 2017 16:48:05 GMT -5
I would first set your supply to 3.3v before connecting it. Then connect the pos to the pad of L713 that was "NOT" connected to IC73. Then connect the neg to DGND where ever. I would turn on the supply and not even plug in the receiver yet and see if it holds the 3.3v Then see if any ic's feel hot. It looks like that 3.3v line powers a bunch of ic's, not just the 2 you checked for heat before. So feel around. If nothing seems hot and the 3.3v holds then plug in the receiver and turn it on and see what happens. I will await your results. You the man!!!! It worked!! But some display items still had either a foreign language some times and some times english. I was able to select inputs and change radio stations. All this not connected to any speakers etc. Now I need the part ! Nashou |
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Post by mastertech on Feb 18, 2017 17:13:17 GMT -5
It may need a master reset to clean it up. Plus you need to hope all the HDMI ins and outs work.
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nashou
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Post by nashou on Feb 18, 2017 17:16:48 GMT -5
It may need a master reset to clean it up. Plus you need to hope all the HDMI ins and outs work. SO I need that chip right? Where do I get it. I looked and can't find anyone that has the 38 pin chip I found some but tis 20 pin. Also no data sheet can be found. So I need to test all HDMI ports connected to a monitor first ? Don't i need the chip first to get all the voltages to all the chips first? I understand that chip is a Dc to DC converter correct? Nashou |
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Post by mastertech on Feb 18, 2017 17:34:46 GMT -5
IC73 only supplies the 3.3v . IC77 supplies some of the other voltages to many of these ic's. You can test the output of the regulators off ic77 but I would not bother yet. I would only check them if the HDMI has a problem.
Just use your external 3.3v supply for now in place of ic73 and do a reset and then test out the rest of the receiver. This way if you still have a problem we can search that one out also. I did look for that ic73 last night and I did find some places that have it so I will check again later. They were most likely in China but that is probably the only place you will find it.
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Post by mastertech on Feb 18, 2017 21:36:29 GMT -5
For ic73 it looks like some units use EN5327 and some use EN5337. What is marked on your ic73?
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nashou
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Post by nashou on Feb 18, 2017 22:03:10 GMT -5
EN5327. Believe it or not I don't have a small HDMI TV to test the HDMI video on. I will have to put the Marquee Projector back together to test the HDMI outs lol. I do have a couple flat panels that need to be fixed. But that is for another time. I'll have to keep one for this sort of thing  Nashou |
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Post by mastertech on Feb 18, 2017 22:31:22 GMT -5
You should be able to use the EN5337QI in its place. Both Mouser and Digikey have them so where ever you prefer.
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nashou
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Post by nashou on Feb 18, 2017 22:38:31 GMT -5
You should be able to use the EN5337QI in its place. Both Mouser and Digikey have them so where ever you prefer. Mine has pins not the pads on the underside. Not sure if Id be able to make it fit. I'll have to measure the chip tomorrow. going to bed now/ Nashou |
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nashou
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Post by nashou on Feb 19, 2017 20:39:51 GMT -5
Well I tested the HDMI out and Inputs for video as the only display I had is this Dell monitor with DVI connection . But I had audio for FM out of the right channel . I did a factory rest by pressing the Straight Key while powering up. it then goes into Advance mode and you can toggle through to Initialize all. Then power off and it resets all parameters. I need to test HDMI audio but I have no reason to think it won't work. So now I need to get that Chip. Maybe the one with the "BGA" style pads will fit onto he Pin pads of the type I have. Not sure if there is anything else I should check? Maybe in the self diagnostic mode it might show a fault? I tried to look but didn't have the manual to see what everything meant.  |
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