Hi
Can anyone cast any light on a fault on a control box ?

When pressing micro switch on handle bar the green light on the pod on the left hand bank of lights illuminates.

The relay does not click when micro switch pressed. The relay under test checks out ok.

The motor does not drive when micro switch is pressed. The motor came from a working C5 and checks out ok wired direct.

D1 diode checks out ok

The voltage regulator checks out ok, 5v and 12v

Both X12 and X13 show a +12v when micro switch is pressed. These are the 2 small wires going to the relay. I would have thought one of these should be a negative.

Any help appreciated
Regards
Mick

Hi mick just a thought is the thermistor and the other heat sender on the control board the right way round . Or damaged
Bye Chas
Ps I do have a spare red cable (the one that goes from the c/ box to the pod ) if you want to borrow it ...let me know

Hi Chas
I am lost with thermistors and heat thingys, I can use a test meter follow a diagram and that's about it. I can solder. I can remember most of the poem for resistors, bye bye rosy on you go etc etc but this is my limit.

I have a couple of red cables I know that work and have now changed this.

I am at a loss at the moment with this one.

Regards
Mick

Hi mick just make sure that the connections are as per photo the (Orange and purple ) For the moment forget the rest

Hi Mick,

with everything connected, first check the voltage between X12 and X1 it should be 0v. Press the start switch and check the voltage again, it should read 12v ± a volt or two. Repeat the second test but this time between X13 and X1. If you have a 12v reading then there is a problem with the circuit.

Remove the purple/grey connector from the board, set your multimeter to 200kΩ, test the resistance between the pins on the cable end. You should get a reading of about 20k, if you get this reading replace the connector.

If all is OK remove the orange/orange cable and test the resistance between the pins on the cable end, you should get a reading of 10Ω or less. If you get this reading replace the connector.

Then let me know what your findings were.

Cheers lads for your replies , I am away on Tuesday most of the day but should be back
late evening when I hope to carry out these tests and get back to you.
Regards
Mick

Hi Chas
Orange/orange cable and grey/purple cable wired ok

Hi Karl
Battery reading is 12.52 volt
X1 to X12 with micro switch pressed is 12.52 volt
X1 to X13 with micro switch pressed is 12.52 volt

Meter set on 200k
Orange/orange reading 00.0
Grey/purple has no reading

Regards
Mick

Hi I have just checked one of mine and the results are orange Is 000. Purple is. 10.3 On 200k
Not sure if it means anything ...but I will check more and see if they are the same
Bye Chas

Just checked another two and the Orange is the same 000 Purple ones are 07.4 and 09.1 on 200k
So it looks like it is the purple one at fault ??????????? Mabe
Chas

Hi Mick,

Looks like the thermistor is up the spout, but this shouldn't effect the operation of the C5. You can replace it at a later date, but for safety's sake it should be replaced.

Remove the grey/purple connector. With the system switched on, measure the voltage between X6 pin 2 (second from right) and pin 8 (left most pin), it should be 5v.

Now I need to know if your CB case is completely open, not just the inspection cover removed.

Cheers. Karl.

If you need a purple on I can lend you one for testing
Chas

Hi Karl
Pin 2 to pin 8 on X6 is 5.08 volts.

The cover is completely removed for access to all components.

Is the thermistor on the end of grey/purple ?

Regards
Mick

Hi Chas
I have just tested another spare I have of the Grey/Purple and I get the same, no reading.
I could do with trying one of yours if this is ok with you.
Regards
Mick

Hi mick no problem. Will post in the morning
Chas

Ready packed and ready to post
Chas

Posted
Bye Chas

Hi Chas
Did you test anymore leads, I am wondering if it is my meter ? I will test your cable to see if I get a reading with my meter.
Regards
Mick

Hi mick I only tested 3 but if you want I can test more .
Chas

Hi Chas
Did you get similar readings ?
Regards
Mick

Hi Mick I put the results of the 3 on the site
Chas

Hi Chas, where did you post the results?

In the mean time I've conducted some tests, here are my results:

7.63k, 9.14k, 10k, and 12.54k, but it must be pointed out they were all tested at different temperatures.

The 9.14 was tested at 22°C
10k was tested at 25°C (if the 9.14k thermistor was checked at 25°C then the resistance would have been lower).

The others were tested a long time ago and I didn't check the temperature, but not above 28°C or below 20°C.

The 20k I mentioned before was off the top my head, and, sorry, not the correct one.[blush] [blush]

Hi Karl the results are on the same post ....
Chas

Cheers Karl and Chas.
I now have the leads from you Chas and will hopefully have time this weekend to try a few swops on the control board. I have been advised to swop TR3 first and then test again, if no success then swop the op amp and test again. I now have 5 boards with different faults, so now equipped with most components it's just a matter of trial and error once I have a working control box.
I will keep you upto date as I go along. Any thoughts as I am going along will be appreciated.
Regards
Mick

Hi Mick,

I would hang fire at the moment with changing TR3.

I have setup a test chassis so we can conduct parallel tests. If you have more than one suspect board then I recommend you conduct the same test on each board in sequence, this way we don't have to keep the post open till 2016.

Just a tip, keep a check list of what you've done for each board so you don't lose the thread.

Hi Chas,

I found your readings.

The orange/orange connector is the thermal cutout, it should read 0Ω or a very low resistance (allowing for poor connection to the contacts).

To test the cutout, connect the cutout to your ohm meter, apply heat, e.g. a hot air gun or close but not direct contact with a soldering iron. After the cutout has warmed up the meter should indicate no resistance (i.e. open circuit). [color=red]After test ensure the contacts have closed again.[/color]

The grey/purple connector is the thermistor, with the ohm meter set to 20kΩ this should read more than 6kΩ.

To test the thermistor, same as above but slowly apply the heat [color=red]to avoid shattering the glass bulb[/color], and the reading on the meter should drop. Don't continue the test if the reading drops to 900Ω.

Hope this clears things up for you.

[color=red]Edit in red.[/color]

Thanks Karl

Hi Dan,

with reference to replacement thermistors.

The thermistors can be tested at ambient temperature, but the results are irrelevant other than to prove they are not open circuit.

Perran Newman quotes "The two trip levels operate with nominal thermistor resistances of 1100 and 900 Ohms.", but nowhere in his documentation does he quote at what temperatures these trips should operate. This makes it impossible to select a replacement thermistor.

It is apparent from ambient temperature testing that Sinclair have used more that one type of thermistor, the only thing that was important was that their characteristics were correct at the nominal temperatures.

So would it be possible to check with Perran concerning these trip temperatures (temp warning and temp cutoff)?

Cheers. Karl.

Hi Karl I have sent an email to Perran will let you know when I get a reply from him
Bye Chas

Hi Chas,

many thanks, just hope you receive a reply.

Av Phun. Karl.

Hi Mick,

just a quick run in, I'll be giving values separated by a oblique stroke e.g. 2/5.
The value 2 is in the standby condition (i.e. battery connected), and 5 is the value you should receive with the start button pressed.

First check the battery voltage.

With great care not to cause a short on X9, check the voltage between pin7-X9 and X1, you should have approx. battery voltage/3v.

Let me know the result and we'll take it from there.

Needing both hands for the test probes, I've replaced the start button with a toggle switch.
I'd do this test on all of your boards, but keep a permanent record of each board as results may vary from test to test. Mark one board as the main board and give me only the results of this board.

Av phun. Karl.

P.S. Have you checked the copper lands on your boards, burnouts are quite common.

[color=red]P.P.S. To speed up the testing, send me an email as I only look in the forum now and again.[/color]

[color=red]Edit in red.[/color]

Hi Karl
Email sent. Could we put the results on here when tests done.
Regards
Mick

Hi Mick,

no problem.

Cheers. Karl

I have changed the op amp LM358N as the board already had an IC socket in place. The same fault still remains

Hi Mick,

I think the test described in post #30 may well give us an indication to the problem.

[color=red]Instead of pin7 on X9 test between R10 (lead nearest the X9) and X1.[/color]

[color=red]Edit in red.[/color]

Hi Karl
I have sent you an email but not sure if you have received it.

I have carried out test between x9 pin 1 to R30
Battery connected switch off reading is 5volts
Switch on and reading is 1.3 volts
Regards
Mick

Hi Mick,

I've received no mails through the normal channels. Here's my email address:
([email protected]).

You've just thrown me a wobbler.

I have carried out test between x9 pin 1 to R30

Read posts #30 and #34. They are both the same test but #34 is better for safety reasons.

Where in the hell did you find R30, there's only 12 resistors on the board.

Please redo the test and let me know.

Hi Mike,

as I mentioned in my email, the op-amp has no direct influence on the relay. It's there to measure the current used and voltage level.

But so long as we are on the subject of op-amps, seeing that you have the CB PCB removed for repairs, you can make the op-amp mod.

http://www.c5owners.com/sinclair-c5-forum/yaf_postsm4829_Perran-Newman-s-Op-Amp-Mod.aspx#post4829

When replacing TR3 [color=red]don't use too much heat[/color] with the soldering iron.

Hi one and all,

C5mick quote.

Could we put the results on here when tests done.

Sow hear it iz.

Pod turn out to be OK.
The thermistor was up the spout.

After the initial tests I came to the conclusion that TR3 was dead (RIP). Mick replaced it but the board was still dead. Unfortunately Mick misread the pin connections on connector X6 (very easily done as pins 3 & 6 do not exist), which in turn mislead me. ](*,) ](*,) I had the feeling we were going round in circles, it finally came down to ................ wait for it.........................TR3. The replacement transistor was also very dead.

Mick was going to replace TR3 at the beginning, but it would not have helped as the thermistor was dead, and so was the replacement TR3.

Mick now has the board up and running.=d> =d>

Don't worry Mick you haven't given me any grey hairs, they were all grey to begin with.

Cheers Karl for all the time and effort put in to helping me enter unchartered territory as far as I was concerned. I now have a far better understanding of the control box .

Also thanks to Chad for his help and the use of a known working thermistor.

Cheers
Mick

Hi Chas,

with reference to post #28, did you receive any reply from Perran, as it's very important? Without these figures I can't start to seek a replacement thermistor.

I had a figure of 70°C stuck in my head, but after checking the TUSC5SM it turned out to be the max temp for the casing and not the armature. In the TUSC5SM they show a graph of temperatures in the 150°C region.

So when testing the thermal cutout the activation point is 70°C ±5°C. OK ole.

This is the only info I can find.

Cheers.

Karl

Hi Karl no I haven't so I have just sent another measage .
Chas

Karl do you want the spcs for both items (one in the tube or one that clips on the side of the motor)

Chas

Hi Chas,

the one that goes in the tube (purple/grey leads) is the thermistor. The one that clips on the casing (orange/orange leads) is the thermal cutout.

I info I need, in relation to the thermistor, is the temperature that operates the audible warning, and the temperature that operates the motor cutout.

With this info I can check for a thermistor that meets, or almost meets, these parameters. By fitting the wrong thermistor there is a chance of damaging the ULA.

The only info I can find relates to the resistance the thermistor needs to operate these functions but not the temperatures.

We've seen what can happen to the armature due to overheating in the USA case.

Cheers.

Karl.

Hi Karl measage sent to Perran all the best Chas