vertical lines on lcd after replacing backlight

The Yamaha SY99 is a synthesiser combining frequency modulation synthesis (branded as Advanced FM) and sample-based synthesis (branded as Advanced Wave Memory 2) and the direct successor to Yamaha's SY77/TG77

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radiolite22
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Joined: Sun Aug 23, 2015 11:38 am

vertical lines on lcd after replacing backlight

Unread post by radiolite22 » Sun Aug 23, 2015 6:00 pm

Hi, need some help or advise here...

Recenty I tried to replace the backlight of my sy99.

followed Christopher Baxter's guide as I couldn't get the old backlight out.

After reassembled everything and powered on, the light works but the lcd dot matrix are only half readable. There are a few vertical lines on the lcd.

http://i841.photobucket.com/albums/zz33 ... 182618.jpg

Image

http://i841.photobucket.com/albums/zz33 ... 182546.jpg

Image

The lcd was working fine and all wordings are clear. Was just pretty dim so I wanted to replace the back light.

So I thought I may have reassembled the lcd wrongly and dismantled everything again, fixed back and now it seems worst. More vertical lines. .. :( Now it is hardly readable.

Lcd reading was working fine prior to replacing the backlight so I dun think it's faulty.

Anyone can help? :(
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shadowmask
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Re: vertical lines on lcd after replacing backlight

Unread post by shadowmask » Sun Aug 23, 2015 6:26 pm

Hi,

This kind of thing happens when the conductive rubber strip between the LCD and PCB is out of place / dirty / not enough pressure on it.

The two pictures at the top of this page show what I'm talking about..
http://www.fujipoly.com/usa/design-guidelines/89.html

Maybe it just needs a clean with alcohol and re-seated. I feel your pain - the LCD is the most time consuming component to get at.

Brian
GEAR: SY85 / TG-500 / TG-300 / MOXF6 / FG410 / Supernova II Keyboard Pro-X & Rack Pro-X
PROJECTS: SYEMB05, SYEMB06, EXFLM2, EXM-E3, Waveblade, Datablade, SIIEX24
WebSite: https://www.sector101.co.uk
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radiolite22
Posts: 5
Joined: Sun Aug 23, 2015 11:38 am

Re: vertical lines on lcd after replacing backlight

Unread post by radiolite22 » Mon Aug 24, 2015 2:45 am

shadowmask wrote:Hi,

This kind of thing happens when the conductive rubber strip between the LCD and PCB is out of place / dirty / not enough pressure on it.

The two pictures at the top of this page show what I'm talking about..
http://www.fujipoly.com/usa/design-guidelines/89.html

Maybe it just needs a clean with alcohol and re-seated. I feel your pain - the LCD is the most time consuming component to get at.

Brian
Thanks Brian for the info.

I may have to give it another try and dismantle everything the 3rd time... really a nightmare with all the "screwing" around!!

Will alcohol be sufficient or might contact cleaner be a better choice?

Probably need advise on how to how the pcb board tightly onto the rubber strips..
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