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Fix for broken LCD on Meridian / Nortel / Avaya for M-series phones (eg M3902 M3904) 4

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Mobus

Technical User
Jun 14, 2013
2
ZA
This is a follow-up to this thread (thread798-1656401):

It seems failure of the LCD's on Avaya's M-series phones are quite common. Typically the LCD has missing lines or pixels and sometimes fade in contrast.
It seems the fault lies with the LCD's ribbon cable partially breaking contact with the PCB over time.

I've read on various forums of people having various levels of success reheating the ribbon contact with either a soldering iron or a hot air gun. I didn't try this.

However, completely by chance, I left my broken M3902 exposed to indirect morning sunlight through my office window and the LCD fixed itself! It has gone through this sun-heating cycle a number of days and seems to get better and better each day, to the point that today all lines are back and staying back - even after cooling down.

Disclaimer:
* Use fix at own risk *
* I'm not sure how long this fix will last, but its worth a try *
* Be careful not to over-expose and heat the LCD, as this may turn any LCD permanently black *
 
Thank you for posting this. We have had 60+ 3904s experience this issue and I did know it was a ribbon cable issue but I did not know about attempting to heat it.
I have forwarded this on to our vendor to see if they can get an Avaya PCN issued because this is obviously an issue for quite a few customers.
Previously, they have claimed they have only seen 1-2% field failures so they won't issue one.
 
So, I could pack my car full of bad phones and park it in the sun to heat them up I bet :) Wow, great find and thanks for sharing!

~~
Gene at www.GHTROUT.com
 
Hey Mobus,

Maybe they need to turn the air conditioning in your office? LOL But seriously, that's great that it's fixed. I've also seen a similar problem on some M2000 sets as well.

"Keep the Peace, Use RLS"
 
Thanks Mobus! But where are you...South Africa right? What do we do here in Canada?
Maybe I'll take my bad 3904s to the tanning salon!
 
Another thing that I have done is to crack it open and put some styrofoam sheets in it to keep pressure on the connector when I put it back together.....I bet if you combined that with the heat you could increase your success rate quite a bit......the 3904 sets seem to be the worst offenders
 
Mobus,

A very timely post - for me at least. I had our vendor on site yesterday (and is returning soon) and one of the reasons was to see if corruption in the switch could be causing the failures. Ten in a row! Right now I have a set sitting on the switch terminal as it's running a bit higher than ambient temp.

Thanks! Will let you know what happens.

>****
 
Corruption in the switch causing LCD screens to go out???????? I may have heard everything now.
 
I'll have to try the GHTROUT method of throwing some into the back of my SUV in the parking lot on a couple of warm days. A good number of mine are almost 13 years old.
 
KCFLHRC,

I knew it was a long shot. But I just couldn't believe that I had ten in a row with bad displays! Wonder if a hair dryer would do any good?

>****
 
Today 2 vertical lines are missing again on my M3902, but hey - its still much better than it was.

For those interested in a more permanent DIY solution check out this blog.
It details techniques to fix old cellphone and calculator LCD's but I'd think the same will apply here.
Especially read the comment section by user "uhmgawa".

 
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