Re: Sharp LC-52D85UN that won't power on
I'm not determined the PS is bad. I think my writing and punctuation mislead you. I actually believe the PS is fine. The resistors and diode check good. I am getting 380V across the two leads on one of the large 450V cap (NOT referencing chassis). Admittedly I was using chassis when measuring the TNY264, so that's where I went wrong with my meter.
I'm thinking the CPU is faulty because I'm not getting an output from the PNL_ON line. Thank you for outlining the Hot and Cold side by the way, that is helpful....
Hendog
Member
Last Activity: 05-02-2021, 10:50 AM
Joined: 04-03-2021
Location: Coquitlam, BC
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Re: Sharp LC-52D85UN that won't power on
I have two large 450V caps there. I suspect they're in parallel but I don't know for sure. I'm measuring 380 VDC, and yes I was referencing chassis GND when measuring the TNY264.
See pic of power supply board....Last edited by Hendog; 04-25-2021, 10:06 PM.Leave a comment:
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Re: Sharp LC-52D85UN that won't power on
OK sure, I see IC7121 on my board. My schematic doesn't jive with my board. I can't tell what does what....Last edited by Hendog; 04-25-2021, 09:30 PM.Leave a comment:
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Re: Sharp LC-52D85UN that won't power on
Mmkay...What is th e t-con panel? I don't see any IC7121......Last edited by Hendog; 04-25-2021, 08:19 PM.Leave a comment:
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Re: Sharp LC-52D85UN that won't power on
There is a shortage of parts these days. Even if I wanted to order a main board KE833 XE833WJ, no one has any in stock.
I think I've done what I can with this TV and it might just be time to take it to the recyclers.
Leave a comment:
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Re: Sharp LC-52D85UN that won't power on
Thank you Dick_Barton. You're right I'm missing the PNL_ON voltage. I'll try to include more document details while I'm at it.
I've been focusing on the power supply board given what I've read about them. The problem I have is my PC board component identifiers don't match up with the service manual schematic. On my power supply board RDENCA336WJQZ, I have a TNY264PN commonly found to be bad along with a couple resistors and a diode. So much so, repair kits are easily found on line which contain these components....Leave a comment:
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Re: Sharp LC-52D85UN that won't power on
TNY264PN voltages with Power Led flashing twice and OPC flashing three:
Pin1=-26.47VDC
Pins 2&3= -29.81
Pin4= -29.45
Pin5=59.3
Pin7=-29.94
Pin8=-29.90
After holding +vol and <chan cycling power I get steady Power LED
Pin1=-26.61VDC
Pins 2&3= -29.65
Pin4= -29.62
Pin5=178.6
Pin7=-30.00
Pin8=-30.00Last edited by Hendog; 04-24-2021, 05:32 PM.Leave a comment:
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Re: Sharp LC-52D85UN that won't power on
Not "Identical" symptoms...
When I press the volume up and channel down button while plugging it in I do not get any back light however the power LED comes on solid and no other LEDs are active.
So I took another set of voltage readings from 12 power supply board 12 pin PD.
Pins 1 through 4 = 13.14 VDC
Pins 5 through 8 = 0 VDC
Pin 9 = 3.0 VDC
Pin 10 = 2.868 VDC
Pin 11 = 5V (4.98 VDC) I round to 5V on the first set of readings...
Pin 12 = 0 VDCLeave a comment:
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Re: Sharp LC-52D85UN that won't power on
Reviving an old thread.
Rather than start a new thread I thought I would revive this one since MY TV model and symptoms are identical. Hopefully I can get a little more traction this time around since more time has passed and others may have since solved this one.
I have a SHARP TV model LV-52D85UN
The TV does not light up. OPC flashes 3 times, power flashes 2 times.
Attached is a screen shot of the Service manual explanation for the symptoms my TV is exhibiting.
I measured...Leave a comment:
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Re: New Members - please post your introductions here
Hi all, I'm obviously a new member given I'm posting here first. I'm a two-way radio technician. I got my start in the 80's by taking a radio-TV electronics course then getting a job in a two-way shop. I have not had much experience working on TVs. I found this forum looking to work out a problem with my TV. They're not the same as they were in 80's that's for sure!
I hope I can contribute, but first I hope to solve my TV issue with the help of the knowledgeable ones of this board.
HenriLeave a comment:
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