How to repair / replace damaged clear plastic protector for LCD display on Yamaha keyboard


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I have a a Yamaha PSR-e433 which was in immaculate condition, until I happend to leave some garden gloves on top of the keyboard on one warm day. When I picked the gloves up, to my horror, I found that the (acrylic?) material had melted slightly in the heat, and some of it was stuck on to the clear perspex protector on top of the LCD display. Believing Google was my friend, I looked up how to fix this without damaging the plastic, and the recommendation was to use nail varnish remover. I scrubbed at the screen using tissue dipped in this, and at first I thought it was working by thinning and spreading the melted material, but later I began to think it had actually damaged the screen protector itself, and it was melted plastic that was the white film being spread around. As you can see from the picture my remediation attemp has gone disastrously wrong. What can I do to fix this?

Is it possible to say skim a milimetre layer of the screen off, and leave it looking just the same as before, or does the whole component have to be replaced? As you can see from the picture displaying this model, it covers a large area (that whole rectangle between the two speakers at the top that looks black as that is the colour underneath). If the latter, can I do this myself without too much hassle, or is this a shop job? I am seriously peeved that a couple of poor quality gloves from the Pound Shop have ended up costing me so much. Any advise would be welcome. Thanks
 

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happyrat1

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You've done made a right mess of the job.

At this point replacement of the part is your best option.

It's probably doable as a DIY job if you are familiar with removing and replacing panel controls on the plastic shell.

Frankly it will depend on which parts are available, ie, is the window available separately or do you have to buy the entire top panel assembly as a single unit.

Before you started messing with solvents you might have had a shot if you'd used plastic polish.

https://www.amazon.com/NOVUS-7100-Plastic-Polish-Kit/dp/B002UCYRZU

But now that's you've destroyed the entire panel with solvents your only hope is replacing the entire front panel assembly if you want it to look like new again.

The part is probably so expensive it makes no difference whether you do it yourself or send it in for factory service.

Or if you're a real hardware hacker and don't mind the scuffed up bezel you could just open it up, pry out the window and replace it with a clear sheet of lucite or perspex glued into place.

Either way, if you want it to look like new again it's gonna cost you.

Gary ;)
 

happyrat1

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One other option before you shell out for the part.

Scour ebay and the web for a busted unit with the same model number and selling for parts.

Then buy up the junker for $75 and use the parts to repair yours.

Gary ;)
 

SeaGtGruff

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The replacement might not need to come from the same model, as the PSR-E2xx, PSR-E3xx, and older PSR-E4xxx models (or their YPT-xxx equivalents) are all likely to use the same size plastic sheet. I'll compare them on my YPT-400, PSR-E433, and PSR-E443 to see if they're the same.

Otherwise, you might be able to buy an inexpensive clear plastic sign holder from an office supply store and cut it to the necessary dimensions. Obviously you wouldn't use scissors to trim it, but a heavy-duty paper cutter might work. I have one like this one, only a bit smaller-- it's just two layers of clear plastic folded together so you can slip a piece of paper between them, with a slanted base so it stands up by itself:

https://www.cleanitsupply.com/p-343...der-stand-up-slanted-8-12-x-11-nud35485z.aspx
 

SeaGtGruff

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Okay, having looked at my three keyboards, it looks like it might be best/safest to stick with the plastic piece from another PSR-E433 if you can find one cheap. On the other hand, if you can find a way to cut a "window" in the existing cover to expose the LCD screen plus a little bit of the surrounding case, maybe you could take one of those sign holders I mentioned, cut a piece out of it that's the same dimensions as the "window," and insert it? Basically, all you need to do is get rid of the messed-up part that's over the LCD screen so you can see the LCD screen clearly, yet still have something over it for protection.
 
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Man, I hate when that happens. I should know how to fix this by now myself since I've ruined the LCD covers on equipment over the years and tried to fix them with little success. Polymers is not my game but if it's a clear hard cover I'm thinking its probably acrylic or polycarbonate but I could be wrong. I don't think either of those is workable. Polycarbonate is what they use for clear plastic bottles now. I would not have used nail polish remover or any solvent like that. I learned a lesson on that too. If it's acrylic it may crack into a zillion pieces. Polycarbonate turns whitish with solvents.. The best I ever did was used a fine steel wool but you sure would not want to do that on something like this. I could read the display but the cover was dull and whitish. If I had that to do over again I might treat it like auto body using 1000 grit followed by polishing compound and maybe even clear coat and polishing. Heating it just right would work but it would take someone with good experience. It has to be heated at the right rate and temperature perfectly and uniformly. I tried it once and I saw that it would work but I got one side too hot and it was ruined for good.
I think the previous suggestions are best also unless you found someone who could do it right. I'm not sure the piece Sea is talking about but there should be a similar piece from something you could cut and use.
Really, I feel your pain, that's awful. If you do it right even if it takes more time and money I'm sure you will be more satisfied in the end.
 
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after noticing you had pics I see that it looks ruined anyway. If it were mine, I would mask everything around it real well and try to polish it uniform at least with steel wool, 1000 grit then maybe even polishing compound. It's possible it might turn out pretty good. It would be a lot better than it is. If I didn't like it then I'd find another piece of plastic or maybe find the replacement piece. It would really be better if you just took the cover off or took the piece out. You don't want any chance of getting steel particles or grit into your keyboard.
 
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Rayblewit

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Something you can try (maybe too late, maybe not)
Make up a paste of bicarbonate of soda or baking powder with water. Just a tablespoon for starters. Use less water than the powder so the paste is a consistency like tooth paste. Have about a quarter of a cup of vinegar ready as well. With a SOFT cloth dab it into the vinegar to dampen. Dab the dampened cloth into the paste to collect a small amount (1/4 inch) When you do this it will fizz. Apply it to the perspex and polish with small circular motions. Make sure it is not too wet. You do not want moisture seeping in underneth. Do this a few times. Wipe it clean between each application to avoid moisture penetrating the edges of the perspex panel.
This compound is non abrasive and will not leave scratches.
 

happyrat1

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If you are hell bent intent on fixing this yourself, might I suggest cutting out a new window piece from a heavy duty CD Jewel Case and glueing it into place?

However, how easy this might be depends entirely on how easily the board comes apart and separates from the LCD display beneath.

Should you even attempt to use a polishing compound and/or a buffer wheel attachment on a power drill, I would STRONGLY advise taking the keyboard apart first and working on the panel assembly in an isolated work room away from the electronics.

DO NOT attempt to polish it in situ as the resulting dust and crud will definitely spill into the intricate workings of the keybed and controls themselves and cause far worse problems.

This is ADVANCED HARDWARE HACKING 101 and if you have already demonstrated the inability to address a simple scratch on the display with these results I STRONGLY ADVISE handing the job over to a pro regardless of the cost.

Gary ;)
 
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Yes Ray, baking soda, I'm pretty sure, is sometimes used in a sandblaster for finer work. Yes, I think it would perhaps make a good polishing compound as a paste. It is "naturally" fine and uniform. The vinegar part I don't get except to make it foam and look cool like it's doing something. But then I suppose there could be an effect I'm not considering. I would not want free liquid near that paste unless I had it off where it could all be washed off with water. I've also heard of people using toothpaste to polish things.
lordofpie, I cannot tell how deep the damage is but if the damage is thick above the surface you may need to address that first to get the roughness down. If the damage is thick you might even need to carefully use a flat razor followed by fine sand paper, steel wool, polishing compound, paste. I'd bet if a body shop guy who does rare or classic cars looked at the piece he would immediately have ideas or instructions. There may be youtube videos for automotive type plastic like instrument panel covers or light covers.
 
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from a heavy duty CD Jewel Case and glueing it into place?

Gary ;)
Good one! And we all were probably sitting right beside one and didn't think of that.

Probably not needing to be mentioned, I hope, but all of the ideas of gluing on a new piece would be from the inner side of course.
 
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happyrat1

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To be honest I think at this point attempting to polish out the chemical burn on the window is a total writeoff.

The proper way to do this is to either replace the entire front panel assembly with a replacement part from a dead junker found on eBay for $50-$75

or

The Rube Goldberg Approach which would entail removing the front panel, disassembling the attached electronics, CAREFULLY prying out the trashed display window (which may be press fit and heat welded into the assembly itself), then CAREFULLY cutting out a new window to fit from a heavy duty clear CD Jewel case (Wrapped in masking tape so the saw does not create new scratches) and using a two part epoxy glue to cement it into place.

The latter approach would still leave you with a messed up top panel but at least the window would be transparent again.

What it boils down to is exactly what the does original poster think constitutes a satisfactory repair at this point and what he is willing to live with and sacrifice in resale value.

Gary ;)
 

happyrat1

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To cut out the new window from a CD Jewel Case I'd recommend wrapping both sides with masking tape, then using either a Jeweller's saw or a coping saw or a set of heavy duty snips and a 1/16" drill to mark the corners.

If you don't have adequate tools to do this then don't even try.

Gary ;)
 

happyrat1

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Ya know what? I was looking around the web for deals on dead Yamahas for parts and I realized the original poster can upgrade to a Brand New PSR-e443 for $210 from Amazon with free shipping.

https://www.amazon.com/gp/offer-listing/B00JAEDIP6/ref=dp_olp_0?ie=UTF8&condition=all

Seriously, for that price you wouldn't even be able to buy the proper part from Yamaha and a Rube Goldberg repair would look like hell.

I say just buy a new one and keep the old one for experimental repair work or just sell it on your local craigslist for $75 for parts.

IMHO it just ain't worth the money to fix.

Gary ;)
 
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I forgot about polystyrene earlier. I have repaired cracks on taillights and made things with polystyrene using methylene chloride which essentially dissolves it together and can be seamless. Other solvents like PVC cleaner might work for cracks or joining. I think some call it a"cold weld." Manufactures of polystyrene items actually use the same technique for joining peices. So, polystyrene is particulary soluble in solvents and it does make a big mess if you wipe solvent on the surface. I still think you have polycarbonate or acrylic and more likely polycarbonate imo.

This video shows using a buffing wheel for scuffs and scratches. It also shows use of the Novus plastic polish which Happyrat mentioned earlier. Honestly, the ideas in this thread is going to be helpful to me also for my various repairs and designs. Even if I did just get a whole new keyboard I would polish out that piece on the old one, and sell it as such or give it to my neighbor kids because they would be "scuffing" it anyway :)

 

Oriane Lima

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I have a a Yamaha PSR-e433 which was in immaculate condition, until I happend to leave some garden gloves on top of the keyboard on one warm day. When I picked the gloves up, to my horror
Hello, would not it be interesting to take the keyboard to a store in your city, to a specialist, for him to make an assessment of the damage and make a budget for the repair? If you feel comfortable with his opinion, perhaps, it would be a good solution to the problem
Oriane Lima:cool:
 
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SeaGtGruff

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Well, I think the original problem wasn't a scratch, it was some thin plastic from garden gloves that melted in the hot sun and got stuck to the clear covering that goes over and protects the LCD screen. So if I read that correctly, he wasn't trying to remove a scratch, he was trying to dislodge the melted plastic that had adhered itself to the covering.

Given the apparent thickness of the covering, trying to scrape the mucked-up layer off the top might work if adequate tools were available, but I'm not even sure what those would be-- and certainly it should be removed from the casing before any such attempt is made.

But the clear protective covering appears to me to be largely ornamental, other than helping to protect the LCD screen, and possibly helping to keep grit from getting underneath the large spin dial-- i.e., I say ornamental because it's larger than it needs to be.

I'm not sure if the covering is glued onto the body of the keyboard, or snapped into place, or what-- I couldn't tell on mine.

Replacing the PSR-E433 with a new PSR-E453 or not-so-new PSR-E443 would be a good move as far as being a bit of an improvement-- especially the PSR-E453-- but perhaps a bit more money than he wanted to spend.

However, if the LCD screen can still be seen underneath the mucked-up areas (if not clearly), then another option might be to just play the keyboard as is-- after all, the damaged screen protector isn't affecting the LCD screen itself, nor is it making any difference in the way the keyboard plays; it just makes it harder to see the LCD screen clearly.
 
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There is probably a term which I can't think of right now but yes your perspective can get off and it can become obsessive. For example, my covertible vinyl rear window was broken by a hail storm. I took the top off, got a peice of marine window vinyl and had an amish guy sew it in who does canvas work. There was a little kink where it was not stretched right before he started stitching but he caught it an asked if I wanted him to fix it before he went further and I said no it would be okay. Now everytime I look at the car that is the first thing I see and I hate it. No one else notices. In that case I really should have done it right because that car was show car worthy and I did have it in car shows before. I also knew beforehand that when you let something go like that you end up letting other things go later and you end up with a piece of junk. That car now has so many little things wrong with it that it's beyond my time to deal with. It makes me sick to think about.
Anyway, looking at the pics, if I did decide not to do much with it and it wasn't worth much to me I would still at least steel wool out that mess and then maybe I would even use polishing compound of some kind after. I already have that stuff and would not need to buy anything.
Sea, made a new good point suggesting that there may not be any scratching below the original surface because of how it happened. But still if you want to work with that one you will have to get the hardened goo, above the surface, down to match somehow.
 
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Gosh, I am amazed at all the responses. Truly many thanks to all those who took the time to offer advice. Apologies for the tardiness of my response. Oddly enough, in the email summary I only received notification of the first answer which pretty much confirmed that yes, I had made a damn mess and would need to pay for a new part. I am at work now, but will certainly go through all the replies later and decide on how to proceed then.

Thank-you all again.
 
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If I can procure the part, can anyone advise how easy it would be to disassemble the keyboard casing and replace it? Despite my dismal efforts with the display protector, I have been known to be reasonably handy with straight-forward replacements e.g. the power-on / locking mechanism of my dish washer. If it is not something for non specialists, I don't want to screw up further though....
 

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