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Hello, you did the exact right thing. As these systems age the many pin connections etc can develop a coat of oxide on them and this results in that error code.
If the problem persists, turn off all power to both units then access their printed circuit cards and replug all of the connectors.
When you have what you need from me it will be time to locate the 'finish and rate' link and click on it...that is the only way the company pays me for my time, lacking that I work at my own expense.