bcstedt
Senior Member
Last Activity: 11-20-2024, 01:42 PM
Joined: 06-20-2011
Location: ON, Canada
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Thanks. I have a few K type probes for my multi-meters that I can use. Will give it a try and report back. -
Not much right now. I've got a semi-regulated heat-gun somewhere and a cheap hot-air station (lost in moving). I was curious about using a heat-lamp? I saw a YT repair doing that with a BGA.Leave a comment:
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Based on the info above I'd like to try reflowing the BGA of the mainboard cpu area.
Best/safest method to try? With/without liquid (thinned out) flux?Leave a comment:
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I've noticed a slight bow on the main board at the processor chip which gets pretty hot to touch. I'm leaning towards a issue with the BGA chip so I'll try preheating it to see if that has an effect.
I checked the CPU heat-sink and it does warm up even if the back-light and image is off. It does seem that something needs to "warm up" before it will successfully restart. Still looking ...
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Update: I preheated the cpu area to 55*C using a hairdryer on low. TV turned on successful three times out of three with 10min intervals. Looks like I might need...Last edited by bcstedt; 01-23-2024, 10:47 AM.Leave a comment:
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I've been ESR testing all the caps I've come across and all the PS caps that look ok test ok.
There's a bunch of SMD Samyoung caps (and some others) on the main board that don't test out too well but don't really seem bad. I've replaced a couple (out of 80) but no change yet.
I've disconnected the T-Con board but that doesn't have any affect.
The service doc's I've found so far haven't been to helpful but I'll keep digging.Leave a comment:
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Inverter Boards (caps check out OK)
VIT70023.80 REV:5
[url]https://www.shopjimmy.com/philips-996510010058-vit70023-81-backlight-inverter-kit/[/url]https://Inverter Boards (caps check ...-kit/[/url]Leave a comment:
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Power Supply w Bad Caps
EAY32731102
[URL]https://www.shopjimmy.com/lg-eay32731102-fsp286-6f02-3bs0152315gp-power-supply-unit/[/URL]
Mainboard (some caps getting bad, Samyoung,etc)
EAX38059702
[URL]https://www.shopjimmy.com/lg-42lb5df-ul-aushljm-eax38059702-11-main-board/[/URL]
Inverter Boards (caps check out OK)
[url]https://www.shopjimmy.com/philips-996510010058-vit70023-81-backlight-inverter-kit/[/url]https://Power Supply w Bad Caps<br /...ly-unit/[/URL]...Last edited by bcstedt; 01-18-2024, 01:50 PM.Leave a comment:
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LG 42LB5D, 42LB5DF-UL, 2008-01, Power On Issue, Replaced PS Caps
LG 42LB5D (42LB5DF-UL) from 2008-01, unit is in good shape and no obvious heat damage or cracked solder on the boards.
Problem:
On first power-up the power LED flashes green about 18x and then stays solid. No backlight or image is present. Click power button, wait 10s for a click and the LED turns red. Wait 1-2s and hit power again and maybe it'll power up fully after 6 green flashes. If it doesn't light up on the sixth flash then the cycle repeats.
It seems that if the mainboard power is left on for a few minutes (solid green power, no backlight, no image)... -
Did some solder rework on the SMPS and X-Main boards. Inspect & test the "new" Y-Main board, looks good and significantly less heat damage.
Installed & test. Was getting some hissing noises from the Y-Buffer and the screen looks like this:
[URL=filedata/fetch?id=3169007&d=1703711753][ATTACH=JSON]{"alt":"Click image for larger versionName:\tIMG_20231227_153549_DRO~2.jpgViews:\t0Size:\t4.63 MBID:\t3169007","data-align":"none","data-attachmentid":"3169007","data-size":"medium","title":"IMG_20231227_1.jpg"}[/ATTACH][/URL]...Last edited by bcstedt; 12-27-2023, 05:07 PM.Leave a comment:
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I finished testing the Y-Buffer, X-Main and SMPS boards. All diodes and transistors check out but there is some soldering rework needed.
I've ordered an X-Main board and hope I'll find an acceptable result soon. Updates to follow.Leave a comment:
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Thanks, I'm beginning to see that. I've got a few other things to check before I order a board but I don't even know if the PDP is functional....Leave a comment:
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With the Y-Main board disconnected, the SMPS test points read:
Vs = 212VDC (211 on label)
Va = 54.8VDC (55)
Not sure where to check Vsc & Ve yet.
(I need the Y-Main functioning to get these)
[ATTACH=JSON]{"alt":"Click image for larger version Name:\tIMG_20231214_184503_DRO~2.jpg Views:\t15 Size:\t964.4 KB ID:\t3164733","data-align":"none","data-attachmentid":"3164733","data-size":"full","title":"IMG_20231214_1.jpg"}[/ATTACH]...Last edited by bcstedt; 12-20-2023, 03:49 PM.Leave a comment:
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Y-Main
Small Heatsink
[ATTACH=JSON]{"data-align":"none","data-size":"full","title":"IMG_20231218_1.jpg","data-attachmentid":3164670}[/ATTACH]
Large Heatsink
[ATTACH=JSON]{"data-align":"none","data-size":"full","title":"IMG_20231218_2.jpg","data-attachmentid":3164671}[/ATTACH]Y-Main
Small Heatsink
[ATTACH=JSON]{"data-align":"none","data-size":"full","title":"IMG_20231218_1.jpg","data-attachmentid":3164670}[/ATTACH]...Leave a comment:
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Components I'll be testing shortly from the Y-Main board.
Results are DCV from DMM diode test.
SMALL HEATSINK
Q6000 - SMK1360 MOSFET
/OL/OL/0.525//OL/OL/0.1+/
Q5402 - GT30F123 IGBT TOSHIBA
/0/0/0//0/0/0/ - (shorted)
Q5401 - GT30F123 IGBT TOSHIBA
/OL/OL/OL//OL/OL/OL/ - (open)
D5406 - RF1501 Diode 300V 12A
/0//0/ - (shorted)
LARGE HEATSINK
Q5102 - RJP63F3
/.017/.017/0// same / - (shorted)
D5101 - STTH12R06FP Diode 600V 12A
/0.371//OL/
...Last edited by bcstedt; 12-19-2023, 08:45 AM.Leave a comment:
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Y-Main board
Model No: 50U(F)2P X-MAIN(1LAYER)
PCB No: LJ41-08457A
Rev No: R1.2(09/11/18)...Leave a comment:
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Samsung PN50C540G3FXZA 50" Plasma, power cycling, Y-Main problem, Canada
Just starting to crack into this one and wanted to get the ball rolling.
At power on (plug in), power light on, relays click, repeat (sometimes)
After disconnecting Y-Main from SMPS power stays on and boot up jingle is heard from speakers
Removed Y-Main for inspection and testing
This pic from:
PN50C540G3FXZA Fast Track Troubleshooting Manual - Rev 1/10/12
[ATTACH=JSON]{"data-align":"none","data-size":"full","title":"Samsung PN50C PCB layout.jpg","data-attachmentid&... -
Re: Gigabyte exploding power supply
I've heard (but have not researched) that it is due to a design flaw related to how the mosfets are driven. The OCP circuit might not be the main issue here as many have blown under normal / moderate load.
Interested in what comes of this.Leave a comment:
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Re: Gigabyte exploding power supply
Very nice.
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Re: ESR meter upgrades
Thanks for the tip! I will hunt for 44pin units.
Wait, so what processor is it? Model #?...Last edited by bcstedt; 04-27-2021, 04:15 PM.Leave a comment:
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Re: ESR meter upgrades
STJ, does this unit look like it would work with your firmware?
They don't show the bottom of the board but I'm assuming it's an 8MHz setup.
2021 New GM328A Transistor Tester ... W/ Battery Case
[url]https://www.aliexpress.com/item/1005002426224712.html[/url]Re: ESR meter upgrades<br /> <br />.../ Battery Case...Leave a comment:
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