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Re: HPT5054 Buffers...
Ok thanks I will get ready to pull the power plug
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Re: HPT5054 Buffers...
Refitted and put back with the buffers, the top buffer having the top ic removed.
Same thing, black screen with audio. I never saw a trace of light or anything on the screen at any time.Comment
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Re: HPT5054 Buffers...
can u unplug x and. go into service mode with everything hooked up?Comment
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Re: HPT5054 Buffers...
Remove the power cable or data cable or both to x main ?Comment
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Re: HPT5054 Buffers...
Oops I made a rookie mistake. I forgot to plug in the data cable to the Y Main last night. Was checking the voltages at the parts I installed when I noticed it. Plugged it in and fired it up and...Comment
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Re: HPT5054 Buffers...
Picture has black border on all four sides and some banding artifacts on the top but I will chalk that up to the upper buffer ic not being installed yet.Attached FilesComment
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Re: HPT5054 Buffers...
Three fets and the scan ic. Hope to do the scan ic today.
The black border referred to in my previous post was due to the dvd player and the banding at the top due of course to the missing scan ic not drawing the odd (or even) lines it should be responsible for.Comment
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Re: HPT5054 Buffers...
Having a bugger of a time with this scan ic. Pulled two traces (three actually but one goes nowhere). Tried solder paste and hot air. Tried drag soldering. Ugh. Need to brush up on my skillz lol. Still salvageable though, will have another go later
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Re: HPT5054 Buffers...
These mosfets are compatible, though I can't speak to longevity as the set is still under repair.Comment
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Re: HPT5054 Buffers...
Is the pad under the scan ic for thermal transfer or just ground ? I put some solder paste underneath but only heated from below with my iron and added some fresh solder into the holes.
My second attempt was still better though. I drag soldered and cleaned up a few bridges but when reinstalled the pic came up for about ten seconds then poof - lights out and scan ic blown again.
I got 4 of these ic's for $20 so I'm sure they're chinese junk but shouldn't they last longer than 10 seconds if installed correctly ?Comment
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Re: HPT5054 Buffers...
If you have a bridged connection you will usually blow them immediately. Have done it as well in my early days. I usually flux the pads and fan outwards with a soldering iron. Works like a charm.Did I leave the soldering iron on?Comment
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Re: HPT5054 Buffers...
Ya seemed to run with pic for 10 seconds or so. I was wondering if I had thermal runaway by doing a less than stellar job with the grounding pad.
I also left two live pins floating and now I'm wondering if the potential on those pins is enough to induce an arc over. Was going to tidy them up after verifying the ic was mounted properly but I think that could have killed it as much as anything.
Two down, two to go lol.Last edited by mmartell; 01-29-2014, 03:28 AM.Comment
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Re: HPT5054 Buffers...
Third time is a charm. Had a couple of black lines, removed and resoldered carfefully and all is good. I will attatch a pic only because I am proud of my work)
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Re: HPT5054 Buffers...
Had two destroyed traces. Wired directly to connector. Mercifully they were both on a corner.
Thanks to everyone who helped and inspired me with the confidence to get it done !Attached FilesComment
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All left and right refers to looking from rear of TV (or looking from front with TV upside down)- TV came with vertical bars and no image. Found faulty TVS on left buffer board. Also replaced T-Con (may have damaged the original while hot air removing components, board has slight warp) and have full image but few horizontal lines on the screen. Some of the lines appears to be 2 pixel tall while others are 1 pixel tall.
- Disconnecting left and right buffer board potentially reveals problems on both sides with different signals (unless this T-Con require jumper like Samsung FB_TRDY1&3) Fault
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Problem
This is an LG edge LED lit LCD Display. The LEDs are on the bottom edge of the display. There are 2 bars (left and right) Each bar has many LEDs and a 6 pin connector. Each pin drive several LEDs thus is the highest current flow / heat junction. The weak lead free solder gradually fails with thermal expansion/contraction cycling and increases resistance. PSU will compensate up to a point, then when the current is too high, PSU just shut down the backlight causing a dark display. I have even seen one which the connector just fell off as solder points became completely detached.... -
The MAX9590 provides 14 programmable voltage references and four static voltage references for gamma correction in TFT-LCD displays. Two register banks are provided to store two sets of gamma reference values. Gamma values are programmed into the banks through the I2C interface and the outputs can switch between values in 0.5µs.
The 14 programmable reference voltages are divided evenly into seven upper and seven lower voltages for the upper and lower gamma curves of LCD column drivers.
Each gamma reference voltage has an 8-bit digital-to-analog converter (DAC) and isolation...10-07-2024, 04:18 AM -
Hi all,
I'm interested in understanding how a buffer board chip is working. I know there's about 90 outputs per chip to the plasma panel, but I'm more interested to know about the input pins. I guess that some of them are address pins, but I want to know more.
So far I've found nothing at all. I haven't found any datasheet about the various buffer chips, and I haven't found any schematic for the buffer board using them (Y Buffer Board in Samsung's terminology).
Any information will make me happy. It can be from any buffer chip or plasma TV manufacturer.... -
I just acquired this portable aircon, history unknown. Its behaviour is quite strange:
- When turned on and placed into cooling mode, the upper fan (cold air out) just spins slowly. The compressor and lower fan do not run.
- If the device is then placed into heating mode and then back into cooling mode, the lower fan and compressor kick in and start cooling, but the upper fan still only spins slowly.
- If the device is placed into fan-only mode, the upper fan does not respond to low/medium/high speed toggles - just keeps running slowly.
- Display and buttons all behave normally aside from the
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