I have a medion lcd monitor that was completely dead, no power, no lights, nothing that i fixed by just reflowing some solder joints. i reflowed the vga 15 pin and the dc connection on the power board. prior to me doing this i didnt see anyhting wrong with the board at all. no burnt spots. no bulging caps. i dont know for what reason i did this, i'm new to this lcd repair stuff, but its like a miracle lol. my question is What the heck did i do????? by just simply resolding these parts of the board i fixed this problem??
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Re: Medion 17 inch lcd fix??
Loose DC input = dead unitOriginally posted by starmaxpc
There are 10 kind of people in this world: those that understand binary, and those who don't.- ASUS ROG Maximus IX Code
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Re: Medion 17 inch lcd fix??
ok i jumped the gun here. recently turned this lcd on and now i get nothing. no lights no amber no green. i do notice tho a small ticking sound coming from the power button area on lcd when plugged into its power supply. fortunately i took a pic of the power/signal board before when i took this thing apart before so i hope someone out there can possibly see something. any ideas. thanks.Attached FilesComment
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Re: Medion 17 inch lcd fix??
Are you positive that the power brick gives you the 12v needed?Originally posted by starmaxpcThere are 10 kind of people in this world: those that understand binary, and those who don't.- ASUS ROG Maximus IX Code
- Intel Core i5-7600K 3.8GHz
- 16gb GSKILL TridentZ RGB DDR4-3200
- 1 M2 SSD + 2 WD Blue 1TB (Mirrored)
- Windows 10 Pro x64
- GeForce GT1050
2 x Acer KA240H + 1 Vewsonic VP2130 21 (a cap replacement job)
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Re: Medion 17 inch lcd fix??
yes i tested it with a volt meter and also tried another 12v adapter. same thing. now that i listen a little closer there are two small speakers on the bottom left and right that are making the ticking/buzzing sound.
pic attached is not mine but identical.Attached FilesComment
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Re: Medion 17 inch lcd fix??
maybe you created a solder bridge during the re-soldering of those joints. now you have an short(s) some where. re-trace your steps also an magnifying glass will be helpful.Comment
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Re: Medion 17 inch lcd fix??
ok i've done some deep investigating here....
i rechecked my soldering job. its ok. now....heres what i have discovered.
with the back cover removed exposing all electronic boards, and monitor plugged in to power, i was trying a few things and when i decided to unplug the video lcd cable from the power board lo and behold i got the display to light up to a white screen and nice and bright, then after roughly 10 - 15 seconds it went out and the yellow led power light came on and stayed on till i pressed the power button to turn off. after a few checks like this i tried something different. with the monitor plugged in and powered on to a white screen i plugged the video lcd cable back in to the signal board while powered on and got a signal image "check video cable" on the lcd then after a 10 - 15 second delay it displayed "going to sleep" it powered off and yellow power light came on. i am not able to power this item on with the lcd ribbon cable plugged into power board only when it is unplugged from power board. on top of that when im able to power lcd on to the white screen the green power led does not come but the yellow light does when it powers down. i hope i explained this well. thanks.Comment
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Re: Medion 17 inch lcd fix??
ok im trying to bring this post back to life. any ideas as to why this lcd does this. here goes....Originally posted by starmaxpc
computer turned on. lcd powered on. no green led light on?? i here ticking sound coming from the speakers. i have the back panel off. i unplug the lcd ribbon from the power board. the screen turns white. no led green light. i plug ribbon back into power board. i get windows image on lcd?? this is the only way to get this lcd to work? any suggestions.Comment
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Re: Medion 17 inch lcd fix??
That's the symptom of a power supply that's trying to start, but the load is causing it to current limit. When you remove some of the load (by unplugging the panel) the onboard supplies come up, and can sustain themselves when the panel is plugged in.Originally posted by starmaxpc
Thre are three approaches.
1. Take a picture from the side. Some of those caps certainly look like they are bulging.
2. I001, I004, and I005 are on-board regulators. Look up the data sheets for them and determine which is the output pin on each IC. Measure the voltage on each output when you hear the 'ticking'. Unplug, then plug the panel back in. Measure the voltages again. Replace the caps associated with the regulator whose voltage increased.
3. Replace C017 and the larger electrolytic next to the blue jack.
Hint: Option 2 will give you the feeling that you actually worked the problem through.
PlainBillFor a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.Comment
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Re: Medion 17 inch lcd fix??
Have you checked the smaller caps, specifically the one right behind the DC jack?
Just had a Digimate 17" LCD which ran off a 12v power brick - it was taking longer and longer to get it to switch on, then it wouldn't at all.
Checked the 3 caps 2 x 100uf 16v and 1 x 220uf 16v in front of the DC jack, one 100uf 16v had an ESR of 1.08. Checked all other caps on the board, they had an acceptable ESR.
Replaced all 3 caps with 2 x 220uf 16v and 220uf 25v (all I had to hand) and it's working fine now (even with a missing pad).Comment
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