Please note: The forum is now closed to new submissions. All the existing forum topics and posts are still available, however new topics cannot be created. If you need Sinclair C5 advice please use the C5 Owners Facebook Group.

dadandjames posted:

As a teen in the eighties and an owner of the ZX 81 and spectrum always wanted a C5. Now I have one. Struggling a bit with the electrics at the moment. The control box had obviously had a fire from a short previously. It pedals fine has has the original tyres. When I powered it up all the LEDs on both sides come on. Anbody have any ideas?
posted on: 16/09/2013 19:42:15

Dan posted:

Hi there and welcome to the forum!

The problem with the LED's lighting up on the left (right-side should be fine if your battery is fully charged?) is probably down to your control box and one of the resistors (R1) or LM358 chip.  Are you able to inspect the circuit board and look for damage?

It could also be the ULA chip in the pod, but I'd start with the control box.

You may want to look at this post for pointers on repairing a control box:
posted on: 16/09/2013 19:49:06

dadandjames posted:

Thanks 4 the reply. The circuit board has some damage from the fire. I will get the multimeter out again. The motor works when connected directly. I connected it up to my car battery. When I reconnected the board all the leds came on but I couldn't get the relay to switch. The lights work. I am guessing that because it thinks the battery is overloaded then it is cut out. I will put some pics up soon.
posted on: 16/09/2013 20:27:40

dadandjames posted:

Finally got the circuirt board working today. However all the Leds are on all thetime. Anybody got any ideas?
posted on: 05/10/2013 19:26:32

rekooh99 posted:

Might be worth checking/cleaning the connection of the red pod wires mine gave me loads of problems.So I eventually got rid of the pod and control box.
posted on: 07/10/2013 09:10:03

dadandjames posted:

Thanks I will try that
posted on: 08/10/2013 20:19:06

Poze posted:

Hey Often if the LEDs are all on the time, it could indeed be corrosion inside the red plug that plugs into the back of the pod. And/or corrosion on the 7 or 8 Pins on the pod itself. Also could be dry solder joints on the pins on the pod. What i do is remove the pod, unscrew it to get inside and then try inserting the red plug onto the pins but from Inside the pod (the pins are very long). Usually the pins on the inside of the pod are clean so you can do a test this way. I then clean the red plug with a tooth brush and suitable cleaner (nothing that melts plastic), then dremmel with a fine wire brush the pod pins. This has worked for me in the past. Otherwise it could be anything really (pod, red wire loom/control box) if you have access to a spare pod then try another pod. Cheers!
posted on: 11/10/2013 15:40:06

SINCLAIR C5 CHAS posted:

Hi what I do is to use a pod connector that I have made just to eliminate the cable Then as Poze says check out the pins
posted on: 11/10/2013 18:32:38

dadandjames posted:

We finally got it going, but the thermal cut out goes too quickly. Never mind did a few miles. Is it safe to disconnect the cutouts?
posted on: 19/10/2013 18:18:10

Area51 posted:

Is there any sign of heat when the cutout open circuits if not you could always replace the cutout rather than disconnecting it It may just be faulty
posted on: 19/10/2013 19:21:01

dadandjames posted:

No the motor is fine so I think the sensor or something on the board is faulty. It probably relatesbto the left hand side LEDs being permenantly on.
posted on: 19/10/2013 19:51:12

Area51 posted:

In that case I think you have no choice but to get it repaired or buy another
posted on: 19/10/2013 21:37:39

Dan posted:

[quote=dadandjames;1430]No the motor is fine so I think the sensor or something on the board is faulty. It probably relatesbto the left hand side LEDs being permenantly on.LOL [/quote]

Have you checked the LM358 chip in the control box?  That can cause the left LEDs to be permanently on.  Had that once myself. I've got a box of those chips here if you want one, you just need to unsolder the one in the cb and replace it (ideally putting a socket in first).
posted on: 20/10/2013 05:25:12

dadandjames posted:

I am not sure how to check the chip out. I have checked r1 and that is ok as are the contacts. Can you mailme mhnb@btinternet.com with price of new chip, and do you have the details of the chip holder? I am really grateful for your help.
posted on: 21/10/2013 12:57:03

rekooh99 posted:

I ve got a spare temperature sensor if you want one.
posted on: 21/10/2013 13:33:04

dadandjames posted:

Hold on to it I will let you know
posted on: 21/10/2013 14:28:54

rekooh99 posted:

Ok will do .
posted on: 21/10/2013 15:12:01