Re: sharp LC-65Q7300U bootloop? firmware?
Solved: One open LED.
Power supply board was testing OK. Disassembled entire TV, confirmed 1 LED strip had an open LED. Single strip replaced. TV is fully functional. No firmware update was needed.
So with a single open LED or even the backlights completely disconnected, the power board must detect and continue to search for it at bootup.
p.s. As of this post, there was no firmware for this exact model to be found anywhere.
digitalscorpion
Member
Last Activity: 10-27-2023, 12:13 PM
Joined: 03-02-2012
Location: Providence, RI
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sharp LC-65Q7300U bootloop? firmware?
Sharp
LC-65Q7300U
<p>
TV boots to Sharp logo, then shutdown, then cycles again. I suspected backlights. Opened up and removed backlight connector, power on, same symptoms. Voltage out of power supply to backlights test OK and follow with bootloop up/down.
Used LED tester into backlight connector, one set of pins test OK, one set test Open. But, with the backlights disconnected the TV is still in a bootloop. So aside from a possible bad LED strip... Could I also have a firmware issue?
Google search showed a few other hits on this restarting issue and being... -
Re: Sharp LC-50P66U-completely dead PSU!!
That was 0V as well. I tested multiple pins around N801, all 0V....Leave a comment:
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Re: Sharp LC-50P66U-completely dead PSU!!
Applied 3v via method suggested. No change. C870 = ~168v DC. No other output voltages. At this point I will seek out a replacement power supply board. Thank you for the help....Leave a comment:
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Re: Sharp LC-50P66U-completely dead PSU!!
I understand. i missed your #23 post with that detail.
I will now try to insert the 3v and take a measurement....Leave a comment:
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Re: Sharp LC-50P66U-completely dead PSU!!
Ohh. If no DC output to the main board, how does the main board provide control signal?
I will attempt the 3v insertion on STB line and report back. Thank you guys!...Leave a comment:
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Re: Sharp LC-50P66U-completely dead PSU!!
C815 = 0V
When you say assert the STB voltage, do you mean I should attempt to Insert 3v into it? Shouldn't the power supply board be producting that STB voltage?...Leave a comment:
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Re: Sharp LC-50P66U-completely dead PSU!!
F801 is good.
C870 = 164V DC....Leave a comment:
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Re: Sharp LC-50P66U-completely dead PSU!!
I have no DC output voltages on connector XP903.
Nothing connected to power board currently, receiving no STB voltage, no 12v or 16v as well....Leave a comment:
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Re: Sharp LC-50P66U-completely dead PSU!!
Did you have any luck with this?
I have similar power board with no output voltages.Leave a comment:
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Re: Sony KDL-55HX800 no power
Update: After triple checking my SJ parts kit, I was then getting a blinking red indicator light. Blinks = 12v issue. Could not troubleshoot any further. Ordered replacement power supply board from china. TV works now. Thanks for assistance.Leave a comment:
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Re: Sony KDL-55HX800 no power
Thank you for the link.
hopefully I can report back with findings and positive results....Leave a comment:
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Re: Sony KDL-55HX800 no power
If main board removed from equation, Shouldn't I be able to get full supply voltages on the power board (using jumpered power on method)?
With Power board installed, and plugged into main board, fluctuating standby voltage is same scenario (3v-0v-3v).Leave a comment:
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Re: Sony KDL-55HX800 no power
Looking for more thoughts on this..
I've done a resistor from pin 1 to pin 3 as well. No difference. Only voltages shown is the standby, then when forced on its does up/downs from 3v to 0v (cycling).. Can't get this power board to turn on..Leave a comment:
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Re: Sony KDL-55HX800 no power
Do you mean take that standby pin(pin1) with a 5ohm resistor to ground? This would be different vs pin1 jumped to pin3?...Leave a comment:
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Sony KDL-55HX800 no power
No power. No LEDs.
Purchased power supply repair kit from SJ.. Same symptoms. No power, no LEDs.
Standby voltage is present = 3.3v (CN6152, Pin1). No other voltages.
Jumpered Pins 1 + 3, Standby voltage pulses from 3v => 0V => 3v, repeatedly.
Transistors and diodes seem to test OK. Not sure how to test MIP2H2(IC6201) or CXA3740M(IC6502), although both of these are new and installed with no issue.
Power supply board for reference. Thoughts?... -
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I will need to open it again, but they did look like the same as the 2 shown. Didn't appear separated. I put light pressure on them while watching the screen, no change. Is that where I should be focusing?...Leave a comment:
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Westinghouse WD32HB1120
See pics. Screen shows only that. Power supply is fine. Voltages show up all across the integrated Tcon. Panel ribbons seem bonded fine. no components getting hot.
I have 2 of these, same model, other one image is fine (shows complete display but white washed). Just chalk it up to bad panels with this model?...Last edited by digitalscorpion; 05-14-2020, 02:34 PM. -
Re: marantz MCD 810 cassette deck
When you say 'switch', you mean the actual mechanical play switch? I wouldn't think that would cause any audio disturbance, such as a turn/slide POT would..Leave a comment:
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marantz MCD 810 cassette deck
MCD810. Good condition.
When I press play, the VU meters max out, with or without cassette loaded. The play head or pickup looks like it could have some gunk on it but not sure. I took some isopropyl to it and the meters are still maxed out. Can't seem to locate a service manual. Any thoughts?
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