I have a CM927 which is a couple of years old. Individual cells in the LCD screen are starting to fail - still usable at the moment but a bit disconcerting.
Google gives a mixed picture. Some posters say they have had loads of failures. Others say they have never had a problem.
Anyone here had the problem with a CM927 - either own or supplied to others?
More importantly, have you had more than one fail?
Cheers
Dave R
Does applying gentle pressure to the display make the faulty segments work?
There are two common ways the LCD could be connected to the PCB.
A ribbon cable bonded to the glass, or a clamp arrangement with a zebrastripe rubber connector sandwiched between.
The latter type often can be cleaned up successfully.
I've not had much success with the bonded type.
had the same problem found a diy fix in another forum
Strip the unit and remove the circuit board (just a few plastic clips, no screws). Remove the LCD assembly from the circuit board (more plastic clips and an eight pin push connection). Removed the LCD unit from the clear plastic housing (more plastic clips). Finally heat up the plastic ribbon where it is stuck to the circuit board (hair dryer will do trick) and then firmly press it onto the circuit board... probably worth doing this several times; in effect you are remating the ribbon to the circuit board by softening the adhesive. Put it all back together and it should be working again.
worked for me
I wonder if that will work for the ribbon cable that is unreliable on the LCD disply of our microwave. Several tracks are "broken" but if you ramp up the humidity they work. This is a flat ribbon that splits and is bonded to both sides of the glass of the LCD itself with a rather sharp bend along the edge of the glass.
Just wanted to say thank you for your fix. It worked brilliantly and i now have a fully working display.
The manufacturer seems to have made it less than rugged from your description. Reall for the need of a few more clips instead of glue it probably means many people are binning them. Brian
replying to Phil, Davo wrote: My first thermostats digits died almost over night after about fours yrs being on the living room wall...I contacted the installer and he charged me £70 for replacement......guess what no 2 has now suffered the same fate...after doing an Internet search I found lots of people had suffered the same problem...so I opened up the old thermostat took it apart to reveal the lcd ribbon...very east task with nothing more than a flat blade screwdriver just be gentle and methodical and it won't fight back...heat up the ribbon with hairdryer....like magic the lcd kicked back to life after being completely blank and in its replacements box for almost five years
The hairdryer method definitely works for how long nobody knows but now I have a spare so not worried anymore.
replying to Phil, Albert wrote: This worked for me also.
replying to Davo, nick wrote: i had this problem this week - failing digits. A call to Honeywell was answered promptly, and i received an email within 5 mins asking fort a picture of the screen and the rear serial # sticker and a receipt pic ( not available.
i then had an email with a returns address and an offwr of a new CM927 controller!!
so they seem to have sorted things at their end.
Nick R
replying to David, Dafyd Hopkins wrote: I actually just put mine on the hot water tank for 24hrs. it was registering
40c when I took out just now and the screen is all back..replying to Graham., Mark Dalzell wrote: I have just tried Phil's remedy and it worked first time. Thank you very much indeed.
replying to Dave Liquorice, B wrote: Phil, thank you so much, your fix just worked for us after I called Honeywell and they were only able to advise buying a new unit at a cost of £90! Brilliant :-)
Just tied up this number with our controller.
Thus far has worked fine;!...
screen are starting to fail - still usable at the moment but a bit disconcerting.
failures. Others say they have never had a problem.
My first one failed and was replaced under warranty , it wasn't controlling correctly. The replacement has just failed , screen has some minor defects . More importantly the target temp can only be set in 5 degree steps , e.g. to 20 or 25 , and the room temperature is indicating 35 - clearly wrong. I've tried a factory reset but no improvement.
replying to Davo, Leddy wrote: Hi , I strip the unit down as you described but I couldn't see a ribbon (or what I think a ribbon should look like) . The screen just had 8/10 metal prongs that pushed into a unit . Is this the same unit you're describing? Look forward to your reply
replying to Phil, David M wrote: Cheers Phil, worked a treat for me, my display was completely gone, had faded over the last year. Look for the screwdriver symbols in the battery bay and poke a flat head in to release / unclip the main cover and it is just the 8 pin and some adhesive pads to remove the LDC unit from the motherboard. 3 x 10 secs with a haidryer on high pointed at the ribbon at the top edge, push it down, clip it all back together and the display is now 100% working - wow! I've got three of these so and the display is going on them all but apart from that they are working fine - this has saved me a good few quid!
I've replaced several CM927 mostly because the buttons stop working. Then I found that the old (more robust) design is still available but sold under the CENTER brand (I think that's Plumcenter).
RObert
replying to David C, David C wrote: Further to my previous post. I contacted Honeywell , sent evidence, and they are sending me a replacement. Great service.
replying to Leddy, Simon wrote: I have the same issue - I was able to access the circuit board easily and take out the screen but I can't see anything like a ribbon, only a set of pins. I tried heating these up but it didn't achieve anything when I put the unit back together. :-(
replying to David C, Mike wrote: Thanks for the fix Worked a dream
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