Dodgethis
Member
Last Activity: 12-18-2024, 01:44 PM
Joined: 09-09-2024
Location: Chattanooga
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Figured it out. So where I thought the buffer board was bad after countless checking for a problem, and couldn't find one, and looking on the main board for problems, and couldn't find one. I found out why the right side was showing no picture but had back light and sound. I checked for voltage on the first smd capacitor closest to the U Jumper connector. I kept reading 8v but never the 17v like I could measure on the last buffer board on the left side that was working. I got very close in doing a voltage injection with a 9v battery, or a jumper wire from one working point to the other that was... -
Ok, took a step back, and looked at the main board with it disconnected and off the panel tv. I found some test points to probe with it hooked up and powered on. The values measured is with the jumper installed to produce voltages to the panel. I have the following: VGHD is zero at the test point. I thought VGHD was needed for left CN1300 only but shows it on the right connector CN1301 per the service manual. Still hunting....i was hoping that would be the smoking gun, but i suppose not as the right side produces an image looking at the rear of the TV.
vgh = 30v
havdd = 8.5v...Leave a comment:
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Ok, So i have probed for voltages. Using the black lead on the chassis ground, and using the red probe to grab voltage readings. I started in the direction of the arrow, and stopped mid way as I have a question. What are the crucial voltages that the panel has to have to show a picture? I understand VGL, VGH, and AVDD is important but which are crucial? When the tv Powers on, the right side seems to show a dark blue background when the samsung logow shows up, then turns black.
From where I started per the attached photo, and per the service manual looks like i'm starting at pin 94...Leave a comment:
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Giving a quick update, Still working on TV. I'm trying to fix the right side of the screen that is black. I purchased a LCR tweezer that could read the capacitors in circuit. I didn't find any shorted caps, but the tweezers can tell me the ESR of the cap's. I used Diode mode and had the red probe on a chasis ground and used the negative probe to find any shorts on the caps on the buffer board. Going to find VGH and VGL, and will report back my findings. If anyone is curious the tweezers are called FNIRSI LCR-ST1 10KHz LCR Meter.Leave a comment:
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Yes your correct, I had to go back and check myself. I was mistaken, I don't know how I got 0.2 ohms, but from the top pad of the transducer to the chassis I have open line. So no short. I wanted to ask. shouldn't i be measuring 17 volts DC at some point on the Driver board? I "think" im missing AVDD voltage which should show 17 vols. They highest voltage i found was roughly 8 volts.
I check the working side of the TV, and it shows on the first smd capacitor that it has 17 votls, however I never get close to that on the black picture side on the driver board. I'm hoping...Leave a comment:
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Hey Nomoresonys, I "thnk" if you look at post 31, If you pick one of the two points off the board.( Preferably the pad where the transducer is lifted) Where the illustration is showing the transducer being lifted by one leg. If you had a dmm on "continuity Beep mode" and say black lead on that pad on the board and the otthe red lead checking each point on the U ribbon cable, or Lvds cable it should beep showing continuity and you could mask that area quicker than blindly moving tape at a section hoping for the best as you test it.
Lotas /Diah please correct me...Leave a comment:
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Hey Lotas I masked those pins, The picture didn't degrade, still have a black portion of that side of screen, Safe to say that's the dreaded dead zone?Leave a comment:
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Your needing to see traces inside the cable? I figured you needed to see the gold contacts. I'll work on a better photoLeave a comment:
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Ya Nomo, I agree I won't be buying a Samsung in the future. I'm not impressed that this TV was once over 2k USD, and now its a glorified paper weight. I tried to warn my parents about the quality, but alas they bought another Samsung.
Lotas, I've included photos of the ribbon U cables.I shot gunned from the hip, and masked the last driver board on the left side, and that stopped the boot loop. I believe your on the correct path regarding the left board being an issue, as I was testing and with the U ribbon cable connected the picture degrades. The picture is crystal clear when the...Leave a comment:
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First Capacitor going north from the suppressor I have the following:
C1: 3.992 k ohm
C2: 18.07 K ohm
C3: 304.7 K ohm
C4: 9.49 k ohm
C5: 9.49 K ohm
C6: 220.3 k ohm
C7: 221.4 K ohm
C8: 9.45 k Ohm
C9: 9.44 K ohm
C10: 0.630 Mega ohm ----- Maybe bad?
C11: 302.4 K ohm
C12: 3.96 K ohm
C13: 3.94 K ohm
C14: 3.94 K ohm
C15: 43 Mega ohm ----- Kept Increasing in resistance, weird has to be bad right?
C16: open line ----- obviously bad ?...Leave a comment:
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Thanks Diah, I'll do some research on it, Never herd of it before between you and lotas knowledge
Hey Lotas, its 0.2 ohms left on the board, one leg is soldered to the board. I couldn't measure anything on it...Leave a comment:
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lol!!! Diah I refuse to give up, Lotas I'll have something for you soon.Leave a comment:
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Lotas with the suppressor lifted one leg in that photo, i have 0.2 ohms.
Guys I'll come clean, I screwed up, on the working side i was lifting the one leg up gently on the anode supressor and it came off both sides. I wanted to know if i could read anything and compare the two on both sides. Is it game over, or can we substitute in a component?Leave a comment:
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Hey Lotas, I have attached photos shows the working side, with the TVS diode and anode suppressor. I have one leg lifted on the non-working side, (no photos attached), and could not measure resistance even using skinny probes.
Lotas is the anode suppressor needed to allow picture on screen? If it is lost, can a substitute be used? i.e diode, jumper wire? Just curious?Leave a comment:
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Lotas, Diah, I appreciate your patience. I have include new photos with no shadows. I have included notes on my findings. I believe the TVS Diodes are fine. I checked on the other side of the tv's driver/ buffer board. I received the same results as to to the driver board in question. Can anyone tell me what is that device in front of the 4 TVS Diodes? I ask ask in the color orange box, while in Diode mode, I beeped in different spots of the component. I wondered if that is worth to mention as the right side of the TV displayed a picture and the left side boot looped and didn't provide a picture,...Leave a comment:
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on top E 5 is stated on themLeave a comment:
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