Re: HP ProBook 450&440-G2 LA-B181P
Big thanks!
whitejohnny71
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Last Activity: 02-07-2021, 12:42 AM
Joined: 03-21-2010
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Re: Individual led source for backlight repair - anybody have samsung strips?
Hi folks, it was a un32eh4003 samsung tv. Turned out I have a few samsung strips in my recycler pile, so I swapped the LEDs out (iron & hot air rework tool) and its been running for a couple hours now.
I've attached a pic of the strips. It turned out three 9volts in series will light the whole 9 LED strip.
To determine the bad LEDs I first connected a 9volt battery to my meter's probes and then started with the black probe on the strip's minus terminal. Then I used the...Leave a comment:
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Re: Individual led source for backlight repair - anybody have samsung strips?
Than you Bud! I searched a few times from google and on the site, but i guess I didn't drill down the results hard enough.....Leave a comment:
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Individual led source for backlight repair - anybody have samsung strips?
Hi folks!
Just found a samsung lcd tv with no backlight, power supply tests ok, backlight can be forced on by shorting past part of the string, so I disassembled the panel and found that I had 3 bad leds between the two strips.
Does anybody have a source for generic lcd tv backlight leds?
Or a strip pulled from a samsung with a few working ones?
Thanks for reading, and thanks to all for making this such a great site and forum!
john -
Re: elitebook 2570p bios dump
Sweet, headed there now... Thank you for your help!Leave a comment:
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Re: elitebook 2570p bios dump
This is the post I'm referring to - Techman, are you blanking the dmi info or replacing with new dmi?
And how do i do it lol? How do I blank the DMI info? Just hex in 00s? or...
Id like to know the offsets if anyone has worked them out, or text search strings to find the dmi info in the dump. I've seen the system configration IDs (usually look like A1009D11 or A1002C22 etc) in dumps before......Leave a comment:
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Re: elitebook 2570p bios dump
I meant with a Hex editor like HxD
Ok, so the blank dmi info triggers manufacturing mode?
Hmm, wndmifit probably calls BIOSCONFIGUTILITY. I haven't been able to unlock anything with wndmifit, only lock...
So what I am getting at is - How do I make a blank dump from my units dump using a hex editor? Because that way I can preserve or update ME regions, etc...
With other brands I dump with a ch341 type programmer, then use HxD to edit as necessary, then flash it back...
Thank...Leave a comment:
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Re: elitebook 2570p bios dump
Hi, so you know how to add dmi info to an HP 2570p bios dump - can you explain the process for us?
Some of the units we buy come bios locked, so I usually download a dump and then use the nbdmifit and windmifit tools to enter the info. This doesn't always work - sometimes the tool thinks the bios is locked even though the post screen says its in manufacturing mode which means its unlocked, right?
So I'd like to take a dump, add the dmi info, then flash it. So, if you can help I appreciate it!Leave a comment:
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Re: ISL95833 +VCC_CORE ok, But no +VCC_GFXCORE_AXG.
I am working on this same board. You should also check the high side fet PQ700, mine was shorted. Same symptoms. I havent replace the ISL95833HRTZ yet.Leave a comment:
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Re: Need HP Pavilion g6 -1c50la Schematic
I'm looking at one of those boards now, with the analogix lvds chip in u12. I hate this board. I think the "Rocky AMD Sabine 15" DB schematic" is pretty functionally accurate, but the numbers are off. If your board does nothing when you press the power button but it does show the white ac adapter led when plugged in, check U28 - its U9794 in the attached scheme. Its a TPS51218 that makes the 1.1volt always on power. The system won't even begin to start without it....Leave a comment:
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Re: Zenith Z42PX2D - plasma - audio, no video
I'll prob not be back to it for a day or so (i normally do laptops and desktops; gotta keep the flow going) but if anyone is familiar with this model or the 42v6 if you could let me know where the test points should be I'll try that as soon as I can get to it. Its my understanding anything between 100 and 470 ohms between the points is ok right?Leave a comment:
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Test points - LG panel
Hi, thanks for your help Alastair. Yesterday after reading about the test points in another Zenith thread, I checked but couldn't find anything in the service manual.
The panel is an LG PDP42V7. I had to remove it from the table for lunch (my office workbenches are full at the moment) but I will check the last digits later. I've attached a pic of the stickers.
Any idea where the test points are?...Leave a comment:
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Re: Zenith Z42PX2D - plasma - audio, no video
From what I've read, can I pull the lvds feed to see static like with an LCD or should I net do that? Def not trying to make anything worse.Leave a comment:
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Re: Zenith Z42PX2D - plasma - audio, no video
I have the service manual. Is it possible for this symptom to occur if the voltages are out of alignment?
Hmm, ok, aligned at Va=65 and Vs=184, off then on, no change. Hit power button, green led blinks 5 times, 3 seconds later, hear audio static but no picture.Leave a comment:
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more info
Also, on the left side, the 3 metal plate power connectors between the y-sus and buffers measured -32, +17 and -32 to ground. I've circled them in the attached pic....Leave a comment:
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Zenith Z42PX2D - plasma - audio, no video
Hi Folks, looking at a Zenith 42" model Z42PX2D. The unit powers on with a black\blank screen. Tiny little sparkles of red and green can be seen randomly around the screen. I hear open channel static and the volume controls work. The channel button cause the audio to mute for a moment so it appears to be working. (I don't have cable tv or a signal source at the moment so I haven't tried to verify that further). So it seems the power supply and the mainboard are ok.
I measured all regular and smd fuses visible and all are good. All power supply output voltages measured correctly.... -
Re: Gateway FPD2185W
Yeah, I'm just figuring that out now; I've been doing motherboards for awhile now, and on so many laptops where the screen doesn't work its a bad connection to the bulb - so I'd gotten used to looking for that. Recently I started doing LCD monitors and Flat-Panel TV's (funny how people will pay more to fix their TV then their computer isn't it?) and haven't really done enough homework on the basic circuit theory. I was referring to a pair of Acer monitor schematics when I noticed the 5 to 1 thing.
Do you have, or can you point...Leave a comment:
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Re: Gateway FPD2185W
Ah HAH!!! If you still can't get rid of the flicker (mine came back) here's some info and a possible fix for it... Worked for me anyway.
There are six lamps. One side of each lamp connects to a bigger transformer. The other side connects to a smaller transformer, which appears to be only for sensing (although I could be wrong). The circuit is in two halves, 3 lamps on each big transformer. However the protection sensing circuit is not split evenly - if you follow the traces you find that the first lamp (board traces/bottom up, ccfl connectors...Leave a comment:
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Re: Gateway FPD2185W
@Bluto:
I just repaired one of these; it had the one-second-on backlight issue as well. The caps were good; this was a later year model I guess. When I would power it on, in dim light I could see arcs all over the inverter transformers and output traces/joints. Looked like mine had dry solder joints all over the high side and burnt ccfl leads.
First I reworked the board, then I repaired the ccfl leads. I still got 2 or 3 bulbs on each side lasting a second when powered on. I noticed there was a lotta volts between the lcd chassis and...Leave a comment:
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