sundance-communications.com/forum Forums TDM Business Telephone Systems Avaya - Lucent Telephones & Systems Buttons don't work on Lucent MLX-10D

We have been using Lucent MLX-10DP Phones without any problems. We also have a few MLX-10D phones. Sometimes all the buttons on these MLX-10D will stop working. You can't dial numbers. You can't use speaker phone. Can't transfer. But they can still receive calls. I unplug and plug the phones back and sometimes that will help temporarily. Or I may move the MLX-10D to a desk that had a MLX-10DP. The MLX-10D might then start working for a few days. The two models are the same except the MLX-10D phones that don't always work are missing an adjunct port that we never use anyway. Anyone have any ideas? Could it be that the voltage that our phone system puts out to make the digital phones work is borderline low?

"Sleepy Sets" - a know issue with "flex boards" inside of the sets. Not an issue with the DP sets, as you've found. Purchase sets from a reliable refurbisher who will have already replaced the flex boards and you should be fine. AND, stick with the DP sets wherever possible.

Is there a way to fix a “sleepy set”? Sounds like a circuit board in the phone needs to be replaced. Is there any other options?

Sleepy sets are intermittant failures due to oxidation of the flex circuit. These are traces of printed conductive ink that gains resistance over time. As they age, the resistance of the ink varies with humidity/temp etc.., which is why they sometimes work, then don't, then work again. I can repair these for you, check our web site www.testtech.com (its going through some redesign right now so might not be working) or shoot me an email for pricing.

[This message has been edited by telsetrepair (edited February 15, 2005).]