Engineering has identified an issue where some Symbio 700 boards may shutdown when exposed to sunlight. The issue has been narrowed down to two components on the Symbio 700 main board, opto isolators U18 & U19, it is believed that the light is penetrating the case of the components and interrupting the internal transfer of light causing powering issues through the components.
Opto Isolators (also known as an optical coupler, photocoupler, optocoupler) use light signals (typically some form of IR light) passed from a transmitter to a receiver to isolate high and low power.
At this time, if this is the only issue with the board, replacement is not necessary. The issue can be resolved by covering the components with electrical tape or keeping the cover in place.
Future revisions of Symbio 700 will have these components moved to the underside of the board along with possible revisions to the components.
Update:
As of June 22nd, 2022, the Symbio boards will have a RTV silicone covering the U18 and U19 chips to prevent sunlight from affecting the boards until a board redesign can be implemented.
The first serial numbers of the Odyssey units that left the factory with the RTV covering:
- Single Condenser: 22243359YA
- Dual Condenser: 22243448TA
In early 2023, the second generation of Symbio board was released to the field that moved opto isolators U18 & U19 to the back of the Symbio 700.
Front of 2nd Generation Symbio 700
Back of 2nd Generation Symbio 700, couplers still have white RTV covering
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Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.