Re: 47LV5400 Component Values and Schematics
Without a schematic or guidance I can't go any further. Now looking for an inexpensive used 47LV5400 EAX63333404(0)
Elwood
Member
Last Activity: 03-17-2021, 08:26 AM
Joined: 01-23-2020
Location: Toronto
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Re: 47LV5400 Component Values and Schematics
Before posting the last message I cut the trace on the output side of L505. The the short is definitely further down the line. I also removed the heatsink to see if there were any visible signs of damage. Further, I checked all caps on the bottom of the board in that area. C292 was giving about the same reading so I removed and checked it. Still no luck....Leave a comment:
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Re: 47LV5400 Component Values and Schematics
I wasn't sure what you were getting at because the output voltage is 0.9V and the current is max 7350 mA so the resistance should be around 0.12ohms. Even if the current was half of that, the load would still be barely readable with my crappy meter. That got me to thinking that I should check the power supply output caps as one might be shorted. I removed C522 and C525 and the line is still looks shorted to ground. Does anyone know if the core current is always near the 7350mA rating or only when running full out? Does anyone have a schematic...Leave a comment:
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Re: 47LV5400 Component Values and Schematics
My bad. Shorted source to drain. If the gate was shorted the 4.7 ohm resistor would have probably blown and it didn't.Leave a comment:
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Re: 47LV5400 Component Values and Schematics
Sorry, I should have said gate to source. The source connects to the 0.9V Core which is very high current and reading from it to ground is as good as ground to my meter. The 0.9V output is very high current so I'm not expecting to see any difference between this line and ground. If this is not the case, please let me know.Leave a comment:
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Re: 47LV5400 Component Values and Schematics
Q503 was shorted from gate to ground. The resistors are OK. Q508 appears to be OK but I would change it if I can get one.
No luck finding the Mosfet in the USA or Canada but lots in China and elsewhere. In my industry the Chinese semiconductors were bad news but I don't think this will be the case on a 25-cent item. Anyhow, I was hoping to wrap this up. I messaged a USA ebay seller who sells parts for this board as they also do repairs. He replied quickly and said he only stocks the common failure parts....Leave a comment:
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Re: 47LV5400 Component Values and Schematics
Thanks for the info Will62! I saw your reply this afternoon and couldn't wait to get home to give it a go. I tore into it and removed the caps. Still shorted! Damn. I immediately felt sad. Next, I cut the trace leading to IC501. Still Shorted. Removed, Q503 and of course no more short. I will try Digikey and Mouser unless anyone has a better suggestion. I'll order a couple of each just in case. Any other suggestions appreciated.Leave a comment:
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Re: 47LV5400 Component Values and Schematics
ummm look closely at the image. The choke is not there. It disintegrated! If you have a schematic and/or could tell me the value of the choke it would be helpful. If you have the part/no for the mosfet maybe I can check that it is not shorted.Leave a comment:
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47LV5400 Component Values and Schematics
I'm not ready to troubleshoot this board yet because there is a visible component failure. L502 blew! Can anyone tell me the value of this inductor? I tried reaching out to the folks who sell the repair kits for this board and they said that component is not a common failure item.... -
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Was interested in electronics as a kid and never got away from it through my entire working life. I joined to see if I can get help repairing some TV's. Thank goodness for this forum. Even with all the info out there these days, you can get more and better info here in one thread faster and more accurately than you'd get from a dozen youtube videos!Leave a comment:
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