Re: Looking for schematic for Vizio M75-C1 or similar
yes i did that .. after more messing with it the backlight and t-con voltages do fire up every second restart so all the voltages and supplies are working but I dont even see a flicker on the screen under a strong lamp .. the voltages all pop up and the bottom corner white power light starts and nada
.. I removed the heat sink all the thermal compound and cleaned the chips and reflowed again .. decided to go a little hotter 440degF about two minutes and still the same thing
.. at this point I am on the...
jimmyboy111
Member
Last Activity: 07-22-2023, 12:37 AM
Joined: 02-12-2013
Location: Houston Texas
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Looking for schematic for Vizio M75-C1 or similar
anything M with C1 at the end would work giving some hints
.. it looks like another motherboard yet again .. did reflow with rework gun and very little changed .. the bottom processor turns on but the top one only at random along with the T-con and no backlights .. also looked at the buck converters and regulators on the mainboard .. they look to have normal voltages .. the white power light on the bottom corner flickers at random .. sometimes it turns on sometimes not when I cycle the AC supply
.. next ESR on caps and look for shorted MLCC's .. not having a schem or...Last edited by jimmyboy111; 07-20-2023, 01:45 AM. -
TCL Roku 65S421 - Double Side by Side Image
.. swapped mobos and matched them close as possible .. now this .. two images side by side I am guessing wrong resolution .. everything else is working fine
.. unable to get into service mode with new update any help is appreciated
[url]https://imgur.com/a/Mzhz0Iw[/url]
[url]https://imgur.com/a/fxB7wV8[/url]https://.. swapped mobos and matched...reciated<br />Last edited by jimmyboy111; 07-11-2023, 11:08 PM. -
Repair Log - LG Plasma 60PN5000
original complaint was he snapped the HDMI 1 port from the board while pulling a cable and it was running at the time .. it partially powers on but no image on the screen
.. service manual was difficult to find
-- LG 60PN5000 PU31A.pdf
.. found schematic on [url]http://televid-sib.ru/index.php?topic=19419.0[/url]
(shout out to the Russian and Ukranian electronics guys)
.. put back HDMI port after microsoldering .. be extremely careful tons of tiny microresistors and smd caps near the port .. luckily all the pads were still in good condition and not torn but TV... -
Re: Samsung UN70NU6900 red light two blinks
Hey Gayric .. I know you posted this 2 months ago but my last idea was to test all the voltages on the flatcables going from the mainboard to the LCD panel edge driver boards .. it is irritating that the TV does not come with a separate Tcon board and it is integrated in the mainboard .. actually I still have the TV .. the lady decided to not bother getting it since it was a 40 minute trip
.. the service manual actually lists all the voltages on each flat cable if you look for it .. you will need a fast scope to see if the...Leave a comment:
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Repair Log - TCL ROKU 65S4 BACKLIGHT DEAD
[B]Hopefully I can save someone some time or maybe they can avoid fixing these garbage epoxied TV sets[/B]
.. stripping down was a pain .. tons of screws all along bezel edge .. the top of the glass LCD panel is glued to the casing (for a reason)
.. all in all took around 4-6 hours to repair teardown .. swap .. reassemble .. current adjustment and then burn in and extra evening
.. single blown backlight led top left row .. 3030 5.5v (6v) .. I had some in stock from another set
.. swapping LED no problem .. one bad led .. the solder pad under this LED is normal... -
Re: Samsung UN70NU6900 red light two blinks
Tested chips with scope .. firing up and oscillating fine until the error code hits so giving up No Fix .. owner came by to get TV
.. hopefully next one goes betterLeave a comment:
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Re: Samsung UN70NU6900 red light two blinks
You're correct .. VCC staring me right in the face so 3.3v on pins 1 and 7 should be ok
.. didn't get much further today .. had to deal with an firebug trying to burn my house down
.. I guess I will live probe all the chips on the panel driver board and the t-con section on the mainboard in the morningLeave a comment:
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Re: Samsung UN70NU6900 red light two blinks
Yes for pin 8 only .. it says 2v max for the logic pins table 9.1
.. this TV has 4 separate panel driver boards so I decided to disconnect each one back and forth .. same thing .. it gives 2 blink error with everything plugged in .. I disconnect one and it stays on
.. after looking closer I see a slight horizontal line across the top of the LCD panel when it first turns on .. the screen is black but this is a shade lighter .. so this may actually be a bad panel
.. still going to probe with scope to...Last edited by jimmyboy111; 12-10-2021, 09:39 AM.Leave a comment:
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Re: Samsung UN70NU6900 red light two blinks
closest I could find so there is a chance I could be wrong .. will have to probe around and see what happens in the morning
also checked the flat cables for any oxidation or burnt spots .. reseated all the connections between the boards and closely looked at the mainboard .. nothing yet
winbond W25Q32JV 0900766b81622f8f.pdf
[url]https://cdn.badcaps-static.com/pdfs/428f9eb0f33285e82989634b2433bb13.pdf[/url]Re: Samsung UN70NU6900 red light two...re is a chanceLast edited by jimmyboy111; 12-09-2021, 08:28 PM.Leave a comment:
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Re: Samsung UN70NU6900 red light two blinks
MLCC's on driver board check out .. Winbond 25Q32JVSIQ eeprom chip is showing 3.3v on pins 1 7 and 8 .. 8 is VCC so this is not right (at least on the datasheet)
.. not showing a short between the pins .. will probe chip with scope and reboot to see if there is activityLeave a comment:
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Samsung UN70NU6900 red light two blinks
.. found the manual .. 2 blinks is panel error
search yandex ..
Samsung+UN65NU6900F+Chassis+UEZ83.pdf
.. psu voltages are normal .. tv cycles backlight on and off 5 seconds .. 2 blink code
.. disconnecting both flat cables from mainboard and the TV stays on backlight and the CPU is running .. no hotspots or faulty voltages
.. disconnected one side then other flatcable from t-con .. the tv stays on .. black screen no images and backlight running .. no blinks when one or both t-con cables are disconned
.. visual inspection .....Last edited by jimmyboy111; 12-09-2021, 06:56 AM. -
Re: Fisher Scientific T-30 Metal Detector - Circuit schematic
It is running and oscillating and I can hear a very quiet low hum putting on some regular headphones .. it was probably meant for some piezo headphones with high impedance since the output is so quiet
.. I will try to check each oscillator and look at the signal closer with a scope tomorrow and maybe trace out the circuit a little now that I have a rough detector circuit to draw from and look for some parallels
.. I reconnected the cut wire to the variable plate capacitor to the control...Last edited by jimmyboy111; 09-22-2020, 10:24 PM.Leave a comment:
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Re: Fisher Scientific T-30 Metal Detector - Circuit schematic
I found a circuit that looks similar to the one here and shows the basic function blocks of these old detectors .. I may look around and see if I can find a schematic from another detector circa 1960-1970
[url]https://www.nutsvolts.com/magazine/article/build_a_four_transistor_metal_detector[/url]
.. i scoped out those transistors and resistors .. the old carbon resistors drifted .. that is why the knew ones were piggybackedRe: Fisher Scientific T-30 Metal Det...chematic<br />Last edited by jimmyboy111; 09-21-2020, 06:19 PM.Leave a comment:
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Re: Fisher Scientific T-30 Metal Detector - Circuit schematic
sure .. uploaded...Leave a comment:
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Fisher Scientific T-30 Metal Detector - Circuit schematic
Looking for service manual for this old thing or a very similar detector it is from 1965 with germanium transistors .. I didn't think there was any real use for it until someone asked
.. some photos
[url]https://imgur.com/a/0fV72w5[/url]
.. board photos
[url]https://imgur.com/a/BlseVfS[/url]https://Looking for service manual f.../0fV72w5[/url]Last edited by jimmyboy111; 09-21-2020, 10:42 AM. -
Re: LG 65UH615A - Backlight on with No Picture Black Screen
You guys are on a roll today [B]Attaboy[/B] .. I put a meter on low ohms and found the ceramic on the driver board with the lowest value removed it and the others opened up guess they were in parallel .. swapped in a ceramic cap from junk board and now it's firing up .. I was about to give up this one
.. the LG 4K tv's have bad ceramics in them I wonder how long before the next one shorts outRe: LG 65UH615A - Backlight on with No Picture Black Screen
You guys are on a roll today [B]Attaboy[/B]Leave a comment:
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Re: LG 65UH615A - Backlight on with No Picture Black Screen
When your right your right .. kind of strange having a micro with 4 pins all connected I didn't look close enough .. pulled out a better ohmmeter with sharper probes and I found 3 shorted caps .. any suggestions on swapping caps so close to tab bonds? I guess maybe some low temp solder and a tiny ironLast edited by jimmyboy111; 06-24-2020, 06:41 PM.Leave a comment:
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Re: LG 65UH615A - Backlight on with No Picture Black Screen
Thanks Bud .. yes did that all showed normal no shorted ceramics .. just checked there is a short to the ground test pad on the board to pins 1 2 3 and 4 on the chip so it is toast .. turned on the board one more time and the 3.3v test pad on the driver board shows 1v but the chip doesnt seem that hot
Diif .. is EDID is unique to this specific TV or could I rip one off another broken panel?Leave a comment:
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Re: LG 65UH615A - Backlight on with No Picture Black Screen
checked the driver boards on the edge of the glass panel .. all look normal no corrosion or dirty connectors .. checked again with scope .. notice that the T-CON main processor is not running normal temp .. dead although there is clearly 12v on the main fuse and the diode input on the board
.. unplugged all the edge panel drivers and now it runs but now the mainboard does not turn on the backlight
.. connected to left alone and the t-con runs but no backlight .. connecting to right driver board and...Last edited by jimmyboy111; 06-24-2020, 05:13 PM.Leave a comment:
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