Could there be some issue with the 5v supply? Maybe a bad cap there?
Sam Scarbo
Member
Last Activity: 03-27-2025, 08:25 PM
Joined: 10-12-2023
Location: Ontario
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The HDMI port has a +5v pin. The USB port also provides a +5v voltage. Could there be some issue with the 5v supply? Maybe a bad cap there?
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That unconnected contact is not the -ve terminal. The top contact is, which is connected to the -ve lead of the electrolytic cap C3.
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You replaced the battery pack and the new battery pack is not charging?
Or you replaced the bulged battery cell(s) and keep using the battery management system circuitry and any unbulged battery cells? 
The battery management system circuitry inside the laptop battery pack usually has some intelligence. It remembers the charge/discharge count. If the count is exceeded, it won't allow you to charge.
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umm, 5X=BB. Could it be this chip RT6575D from Richtek?
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I think 15ohm seems very low to me. If it is connected to one single driving circuit, it may be possible. However, if it is connected as a pull-down resistor and also connected to a driving circuit, it should be in the order of k-ohm; otherwise, the driving circuit could be overloaded.
If broadview/schemetic unavailable, it's better to double-check again and again. Do not rush to put in a low-value resistor. BTW, these resistors seldom damaged.
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I can't see the markings very clearly on those two ICs. If those two ICs are the flash memory XM25QH64A (first line marking unser 'XMC' looks like QH64AHIG), you may check the datasheet to see the functions of the pins.
Looks like the lower left component is connected to pin 3 (WP#, write protect) and pin 4 (vss). Probably it is a pull-down resistor. The other component next to it could also be a pull-down resistor for the other IC. This resistor could have a value of a few tens to hundreds of k-ohm. Try measure with a multimeter to find its resistance and confirm it is really connected...Leave a comment:
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You may check the device TJ30S6M3. It is near the two big capacitors near the output. It could be acting as a fast switching high-current rectifier.
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My two Aneng multimeters were not working recently. One of them was only 2-month new. I know the feeling.
Since you said the fuse was blown and replaced, are there any other components got burned too? e.g. U3, U4, Q2, and the components around there, etc.
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When testing/trouble-shooting, i suggest not to use the original driver speaker. if there is a DC voltage fed to the driver speaker by accident, it will damage the driver speaker ($$$). use a cheap spare speaker or a power resistor to replace the driver speaker during testing.Leave a comment:
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This chip looks bad. Is it burnt?
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As a first step check, i would suggest to open the case, re-seat all the flat cables, and look for any exploded caps or burnt components. Try to avoid messing with the fragile flat panel too much to avoid damaging something else there.
Good luck!
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Try not to mess too much with the fragile panel to avoid damaging something else.
1. If you have a thermal camera handy, check if any of the ceramic caps near that LVDS connector shows any glow.
2. You may try to use a small piece of thin cellulose tape or kapton tape to insulate a few contact pins at a time on the flex cable to locate which one(s) caused the short. It should be some voltage supply pins that have wider tracks on the PCB, rather than some data pins.
Good luck!
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If left quarter ribbon cable is causing the color issue, i would use a small piece of cellulose tape or kapton tape to insulate certain pin(s) on the ribbon cable to see which one is causing the issue.
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thanks for the info. one day, i will try to test this black magic out.Leave a comment:
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If you are not skillful enough to make electrical measurement and such, you may look for a repair shop or a friend who knows electronics for help. Making harsh attempts may damage some more components.
The 2 MELF diodes D700 and D701 sound very suspicious. They should be replaced first with some rectifying diodes that can safely pass 1A or 2. Any repair guy can easily find some of these diodes (e.g. 4 diodes used in bridge rectifier in a DC adapter). It may not be leadless type but just see if they can solder them for quick testing....Leave a comment:
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The post you quoted said the 2 MELF diodes are causing problem as mentioned in that post. They are probably referring to D700 and D701. These are the only MELF diodes i can see in the control pod from your pictures. The post mentioned to replace with some diodes like BAV103. The U701 LM317 plastic casing seems deformed or just dirty in the pictures. You should check all 3 LM317's voltages. That post said they should output 5v, 3.3v and 2.5v. Good luck.Leave a comment:
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That is a LCD TV. Thanks for the reply....Leave a comment:
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Sorry, i totally don't follow how you can generate the -12v from a +5v source using the $3 buck module with a common gnd.Leave a comment:
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Sometime ago, i tried to troubleshoot a 12V wi-fi router adapter that has gone bad. After a few hours of experiments and some exciting firework/sparks, when I found the OB2263 family SMD chip (with "61050" marking on it) was dead, I gave up.
You said you have ordered your OB2362a chip. You should also check the MOSFET is not damaged.
Good luck!Leave a comment:
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I believe have a similar screen problem for my SAMSUNG LN40B530P7F. See photo. It was supposed to show a pure grey picture but it ended up showing brighter on the left (lower-left corner the brightest) and very dark on the right.
Not only the left side of screen is brighter but the contrast is better. When used as a computer monitor, I could recognize the texts displayed on the left but couldn't recognize those very well from center to the right.
I thought it was LCD panel issue. I tried a new T-con board, but same issue. I made voltage measurements here and there, and...Leave a comment:
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