Author Topic: LCD Monitor has rough screen with ripples  (Read 2717 times)

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Offline Rasz

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Re: LCD Monitor has rough screen with ripples
« Reply #75 on: October 05, 2019, 06:59:40 am »
those "practice" boards are useless. Its better to get a piece of actual modern electronics, pcb from random printer or old graphic card will do.
I dont know what you mean by oozing metal, its probably whatever junk is in Fast Chip, gallium? Its always more trouble than help, can corrode metals, needs cleaning.
no hotair = this train wreck :( bend pins/lifted pads.
I hope you didnt mean powering it on in the state from the uploaded pictures, its not even sitting on proper pads not to mention pool of solder.
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Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #76 on: October 05, 2019, 07:54:59 am »
Cleaned the board with isoproply alcohol. Hooked up monitor to pc. No desktop. Just white background.

What does it mean when there is just white background and no desktop. Monitor plugged into PC.

Clean straight lines!!! No fuzzy garbage!! Should I remove the chip again, clean the chip, then put it in? Or is this it? Thanks.
« Last Edit: October 05, 2019, 08:09:26 am by rockblues »
 

Offline Rasz

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Re: LCD Monitor has rough screen with ripples
« Reply #77 on: October 05, 2019, 11:31:30 am »
the chip on your picture is not even sitting on the pads, and half the pins are shorted with solder
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Offline wraper

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Re: LCD Monitor has rough screen with ripples
« Reply #78 on: October 05, 2019, 12:01:37 pm »
Chip misaligned by 2 pads in horizontal direction, most of the pins shorted  :clap:.
 
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Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #79 on: October 05, 2019, 03:58:01 pm »
Chip misaligned by 2 pads in horizontal direction, most of the pins shorted
the chip on your picture is not even sitting on the pads, and half the pins are shorted with solder
Told you the pins on the top had oozing solder come out of the chip. Will remove. Clean. Reinstall.
Sitting on the pads? I see now what you are talking about.  |O  Very small. Any ideas for soldering this to the board? :box:
« Last Edit: October 05, 2019, 04:06:52 pm by rockblues »
 

Offline wraper

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Re: LCD Monitor has rough screen with ripples
« Reply #80 on: October 05, 2019, 04:05:02 pm »
Sitting on the pads? Please explain. How would you add this chip and solder it?
Place chip on PCB so that pins of IC match the pads on PCB and solder it properly. Not put in on PCB randomly, cover pads with bunch of solder and assume that work is done  :palm:. At least use some flux, preferably gel type.

« Last Edit: October 05, 2019, 04:06:39 pm by wraper »
 
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Offline wraper

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Re: LCD Monitor has rough screen with ripples
« Reply #81 on: October 05, 2019, 04:10:29 pm »
Also you shorted C102 and C103 with a solder blob. Not that it matters with all that mess.
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #82 on: October 05, 2019, 04:48:04 pm »
Hi!!! Everything helps!!! Watching your video is fantastic!! Thank you. I have that solder tip. Comments from both of you are great!! Making coffee. Going out to get Kimwipes.

Question - how do you hold such a small chip in place? Tweezer? Tape? Thought Control? I have a magnifying glass that helps.

Question - Monitor is always ON. How do you fix the ON / OFF monitor switch? Earlier, able to test colors - so individual buttons must work. How do I fix this? Thanks!!

« Last Edit: October 05, 2019, 04:53:55 pm by rockblues »
 

Offline jogri

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Re: LCD Monitor has rough screen with ripples
« Reply #83 on: October 05, 2019, 08:45:38 pm »
You could use a small amount of superglue under the chip (but that makes removing it rather difficult). Or handsolder two pins on opposite edges to hold it in place. Oh, and make sure that the chip is not rotated 90°/180° when you solder it back in.

If you have flux, apply a generous amount along the solder pads.

EDIT: Please do NOT use that "SMD desoldering" stuff if it feels mushy when you heat it. They did not provide any information about the composition of that alloy, and that is a massive red flag: Indium is rather expensive (you need 20% Indium for an alloy with that melting point), and if they don't provide the exact composition chances are they cheaped out and used normal Wood's metal. And that stuff is extremely nasty (it contains 12% cadmium, an extremely toxic element), the last thing you want to do is inhale the vapors when you heat it.

About that "the chip kept oozing metal" part: Have you by chance soldered it with your SMD alloy? Bad idea, that stuff is only good for desoldering as it will expand when it cools down to room temperature.
« Last Edit: October 05, 2019, 09:22:39 pm by jogri »
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #84 on: October 05, 2019, 09:17:28 pm »
Original Chip. Circle is upper left corner.
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #85 on: October 05, 2019, 11:07:36 pm »
Can't seem to get solder off the chip. Bent pins and solder between pins. Concerned about SMD Cadmium Toxic vapors. Well the IC chip is off the board again.

Might order one more IC chip and see if I can get it to work with better soldering techniques. Thinking a small drop of superglue might not be a bad idea. Going to throw it all out anyway if it won't work.


« Last Edit: October 05, 2019, 11:17:26 pm by rockblues »
 

Offline Rasz

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Re: LCD Monitor has rough screen with ripples
« Reply #86 on: October 05, 2019, 11:56:49 pm »
superglue is a terrible idea
it seems you didnt see what you were doing, you need some kind of magnification
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Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #87 on: October 06, 2019, 12:57:17 am »
Thanks Rasz. Had a magnifying glass. Problem: put liquid flux all over the replacement carea, and the chip was floating here and there. Hard to hold the magnifying glass,  a tweezer on the chip, and the soldering iron all while anchoring a corner. When anchoring a corner of a chip you only put the flux there? Like to know what people do that works.

Cleaned the chip area. Missing a pad upper left corner. Does it matter?

C102 and C103 - removed solder blob
C107 and C108 - removed solder blob

See the need to get a head magnifier. Amazon.
- https://www.amazon.com/MIYAKO-Magnifying-Illuminated-Multi-Power-Magnifier/dp/B01LX473GP/ref=sr_1_6?
- https://www.amazon.com/Illumify-Lighted-Magnifier-Visor-Removable/dp/B01B7SLFGQ/ref=cm_cr_arp_d_product_top?

Order a 2nd chip?

If I buy a 2nd chip (12.00) and the Head Magnifier (13.00 + Shipping+ tax = 20.00). Total = 32.00 - Need to wait on spending

« Last Edit: October 06, 2019, 01:51:54 am by rockblues »
 

Offline jogri

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Re: LCD Monitor has rough screen with ripples
« Reply #88 on: October 06, 2019, 09:23:21 am »
I personally find those head magnifiers to be a PITA, i prefer a binocular microscope (the ones with x2/x4 magnification) or a USB microscope attached to a monitor. I personally don't use additional flux when i am soldering the corners, i hold the chip down with tweezers (with heatshrink on their ends so they don't glide away) while soldering the corners. A small tip on your soldering iron helps a lot, just apply a small amount of solder to it and touch the pin.

Btw, good news: I found the datasheet of your smd alloy (they had it tucked away on their website), it seems that they use a harmless alloy with indium: https://www.sra-shops.com/docs/srasolder/sds/sds-fastchip.pdf
 
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Offline Rasz

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Re: LCD Monitor has rough screen with ripples
« Reply #89 on: October 06, 2019, 11:21:16 am »
I also find head magnifiers pretty useless, they are a perfect "as seen on TV" Chinese garbage that sounds good on paper until you try one
was missing pad connected to anything? cant see on the picture

hit a local recycle bin/goodwill and pick modern broken piece of electronics (~10 year old laptop will do) to properly practice on real pcbs with ground planes and small pitch chips, repeat until your removed/soldered back parts look just like before procedure.

personally I think you keep throwing good money after bad, especially with no experience. Sounds like you turned monitor on with that abomination of a soldering job = shorts everywhere, wouldnt be surprised if something else got damaged in the process.
Who logs in to gdm? Not I, said the duck.
My fireplace is on fire, but in all the wrong places.
 
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Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #90 on: October 22, 2019, 06:29:06 pm »
- Waiting for 2 replacement IC chips from China
- Practicing removing attaching IC chips on real boards - Great idea Rasz!!
- Will use a VIDEO CAMERA to zoom in on chip as I align it to the pads for correct positioning on the board.
- We will see if this monitor can be saved


- https://www.howardelectronics.com/safe-and-sane-smd-repair/

Removing SMDs The Safe Way
The new, smart way to remove SMDs is with a special solder made by Chip Quik Available at HEI (1-800-394-1984) Chip Quik Products. The solder is an alloy of tin, lead, indium, and bismuth. Bismuth is a heavy metal that's one step above lead on the periodic table, and is the most diamagnetic of all metals with a thermal conductivity lower than any other metal, except mercury.
When tin and bismuth are "amalgamated," it reduces the melting point of the solder to a very low 136 °F, as opposed to the 361 °F melting point of 60/40 solder. When you meld the two together —- that is, melt the new solder with the old — the resultant alloy has a melting point of about 150 °F (well below the boiling point of water). At temperatures this low, it's nearly impossible to damage the solder pads.

Clean up the residue with an alcohol-wetted cotton swab.

The procedure is easy and painless. It involves four easy steps, which are outlined in the photos. The process starts by applying a drop of flux from the included syringe to each lead of the part to be removed. Next, melt a dab of Chip Quik solder on each to the leads using a small (30W) soldering iron — just pretend like you're soldering the chip in place rather than removing it. Be liberal with the Chip Quik solder, and don't worry about solder bridges (slipovers). Once the leads are treated, apply heat to the leads until the new solder is molten, and lift the SMD off the board using a dental tool or vacuum pick. After the part is removed, you'll notice an unsightly mess left behind. This is solder "ash," a result of the interaction between the ChipQuik solder and the old solder, which has to be removed to expose the pad underneath. Clean-up is done with a cotton swab dipped in flux, followed by an alcohol wipe. The Chip Quik SMD-1 SMD Removal Kit contains enough solder to remove 8-10 44-pin SOIC packages.

SMD Replacement
What's left is a clean footprint, ready to accept the new SMD. The new part can be soldered in place using any number of techniques. My favorite is wetted solder paste, like the R244 formula from Kester (available from Digi-Key, 1-800-344-4539; http://www.digikey.com ). This paste is a blend of 90 percent solder and 10 percent gooey flux that is applied in a bead along the newly-cleaned pads using a syringe. With a pair of tweezers and magnifier, carefully align the new SMD in place so that it lands squarely on the pads. Let it set for a few hours to harden the paste. Use a low-wattage iron — about 15 watts — with the smallest chisel-tip you can buy (RadioShack 64-2055, or equivalent) to solder the chip in place. Begin by tacking down two or three of the corner leads. This prevents the chip from shifting while you heat the remaining leads. A trick of the trade is to heat the bottom side of the circuit board to about 150 °F with a hair dryer or hot air gun before soldering the chip. This reduces the amount of time it takes for the solder to reflow when touched by the soldering iron, thereby lowering the heat transferred to the IC and reducing the risk of damage.

Another trick is to drag the solder tip parallel to the body of the IC (perpendicular to the leads) at a rate just slow enough to melt the solder along the way.
Never touch the pads or the pins; let the ball of solder carry the load of the work for you. Combining these two techniques minimizes chip heating and all but eliminates solder bridges.
The final step is to clean up the board using rubbing alcohol and a solder brush or a CFC-free solvent, like HFE-71DA — a hydrofluoroether, azeotrope formulation with trans-1, 2-dichloroethylene and ethanol, from 3M. This mixture is well-suited to defluxing and degreasing tasks, and is intended to replace ozone-depleting compounds. You can obtain free four-ounce samples directly from 3M at http://www.3m.com.

And It's Done! Really — that's it. Sound too simple to be true? Don't take my word for it. Order a free sample of Chip Quik solder via their web site, and try it for yourself. You'll soon discover that there's still life in those defective SMD toys and tools.


« Last Edit: October 22, 2019, 06:37:34 pm by rockblues »
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #91 on: November 07, 2019, 12:05:04 am »
This looks like a great way to Solder SMD - Expensive

How To Solder SMD Using Solder Paste at the Bench. Solder Like a Pro.


$2,335.70
Zephyrtronics - ZT-1-HIS-DPU - AirBath with Digital Control, 25 cfm Air Volume
https://www.neobits.com/zephyrtronics_zt_1_his_dpu_airbath_with_digital_p3969667.html


Less expensive
How to Solder Surface Mount parts (it's easy!) - YouTube


Note - The above technique is NOT USING LIQUID FLUX!!! - Tacks one corner then each leg is soldered.
Liquid Flux caused my chip to "float" - and made it extremely hard to solder the chip accurately to the board. Also my chip was smaller than this chip, not possible to solder each leg one by one.
For very small legs, must swipe across with just a bit of solder left on the edge of the tip.
« Last Edit: November 07, 2019, 12:41:19 am by rockblues »
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #92 on: November 07, 2019, 01:30:12 am »
Need to practice this as well -

Professional SMT Soldering: Hand Soldering Techniques - Surface Mount

1:33 - Uses Kapton Tape to Hold the chip in place while one corner is soldered / tacked in

0:26 - 1) Wipe pads with isopropyl alcohol to clean 2) tin bevel iron tip 3) wipe tinned tip 4) tack solder 4 corners
0:56 - Multilead sweep technique - lay solder against legs and touch side of solder with iron - wipe with fiberglass brush and clean with isopropyl alcohol
1:20 - Point-to-point technique with chisel tip

IC Chip with very small legs -
1:33 - Kapton tape holds chip in place!!!
1:41 - Part 1 - apply solder paste - tack corners - apply strip of flux. Tin iron tip with solder. Run iron across legs flat side down. Wipe w/fiberglass brush. Clean w/ isopropyl alcohol.
2:24 - Part 2 - flux laid down as a strip. Tin iron tip with solder. Run iron across legs - wipe w/fiberglass brush. Clean with isopropyl alcohol.


Another Master Soldering Video - Putting this here - to find it to watch and learn
Master Soldering: Surface Mount Fine-Pitch - Highly Recommended

2:18 - 15 mil ultra-fine pitch
« Last Edit: November 07, 2019, 02:10:21 am by rockblues »
 


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