Sinclair C5 Control board and pod repair.

[@DuncanHobbs-jq2my]

Fantastic helpful video which has been really useful in resurrecting my first C5. Many thanks! My pod allows the C5 to drive but I get all lights all the time on the pod and I'm currently working through the schematics to find the issue. Have you seen this before and if so do you have any tips? Also would you be willing to share the schematic for your pod tester? I'm trying to build one and also wanting to understand what to expect to see by means of output from the control box on pins 6 and 8 of the pod (CSbase and CS emitter). Many thanks and look forward to some more of these videos!

[@sinclairc5electronicsrepai353]

Hi , i'm glad the videos are useful albeit a little rough around the edges. All pod lights on is usually poor power supply to the pod. So I would be checking the output of VR1 in the control box (there is a vid here to show you how). Then check the pod connector for corrosion/dry joints. I do have the schematic for the tester it was the from the original test equipment used by Sinclair, however I need to get permission to share it as it was given to me on the understanding I wouldn't make it public (I have no idea why!?)

[@DuncanHobbs-jq2my]

Videos are fab. Informative and helpful. So I checked the pod and r21 and voltage reg tr3 were both defective. But with power now on the pod I had all left hand led's flashing and lockout on the motor. Back to the control box and replaced op amp IC2. Motor now drives when commanded, but I get a single led on the left hand display, and it's the red led on the right of this display rather than the green LED. Motor spins free and easy so no real load on the motor. Tried replicating a thermistor at 1k and 900 ohms to simulate overheat and motor lockout - all works as it should so need to fault find the current monitor part of the circuit. Almost there. There was a lot wrong with mine so I'm just hoping the ula is OK!

[@sinclairc5electronicsrepai353]

@@DuncanHobbs-jq2my Good effort sounds like you are making progress, I would be inclined to change TR1 and TR2 in the control box and see if that helps. Ideally I would swap the pod for a working one to see if the fault remains in the the control box or the pod but if you don't have one then that is out of the question.