I Originally purchased two Model TCD746320 (in 2012) In 2018 Upgraded TiVo “A” to add external disk In 2019 Upgraded TiVo “B” to Bolt and transferred Lifetime Subscription to it TiVo A is now failing. (On power up, Green power light is on and steady. Yellow Blue and 2 Red lights flash approx. once every 3 seconds. Nothing else happens.) Thus, now: TiVo A has subscription but does not work TiVo B hardware works fine but no subscription I assume the subscription is tied to something on the motherboard. Can I just move the motherboard from TiVo A to TiVo B? Or should I try moving parts (Power Supply?) from B to A?