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View Full Version : New Iwaver 2008 Cooper S RTR: big trouble!


pdugue
2008.01.21, 03:59 PM
Hi,

I've just receive my Iwaver 2008 Cooper S RTR and I'm quite disapointed cause it doesn't work.
I've tried it with full charged NiMh and also new alkalin batterys (both in Tx and car) and I definitely cannot control the car except if I put the transmitter antenna very near of it (2 inches max) and I put the palm of my hand on the tip of the antenna!
I've take a look a the crystals and I notice a strange thing: the labels stuck on the box and on the 2 crystals are 'BAND 02 / 26.995mHz' but the Tx crystal is engraved 13.4975mHz (what does that mean?) and the car (Rx) crystal is engraved 26.540mHz.

I'm nearly sure that can't work this way. Don't you?

(I've send a email at Toyeast customer service to complain).

Regards

Pascal

fangel
2008.01.21, 08:19 PM
Hi Pascal,

I saw what happen to your RTR set.
I have just tested all the band we have in the lineup.
It is true that the engrave is different from box suggested.
I have not heard of the reasons from our engineer yet. But they do works in pair.
Please noticed that the suggested band is 26.995 and half of that is 13.4975. This is same for all of our bands.

I have personally tested a few set this morning, and I could control the chassis without antenna on both TX and RX. I'm not too sure what is the problem, I know that you have put in fresh battery for both the TX and RX, but what is the voltage reading from the TX? Also have you tried putting antenna on the chassis as well? I'm not too sure why putting the palm of your hand on the tips helps, it might be a faulty antenna, you could try removing it and try or maybe it is a band issue.

I would love to help you out, please keep me inform about the situation.

leonen
2008.01.22, 05:55 AM
Hi,

I've just receive my Iwaver 2008 Cooper S RTR and I'm quite disapointed cause it doen't work.
I've tried it with full charged NiMh and also new alkalin batterys (both in Tx and car) and I definitely cannot control the car except if I put the transmitter antenna very near of it (2 inches max) and I put the palm of my hand on the tip of the antenna!
I've take a look a the crystals and I notice a strange thing: the labels stuck on the box and on the 2 crystals are 'BAND 02 / 26.995mHz' but the Tx crystal is engraved 13.4975mHz (what does that mean?) and the car (Rx) crystal is engraved 26.540mHz.

I'm nearly sure that can't work this way. Don't you?

(I've send a email at Toyeast customer service to complain).

Regards

Pascal



Pascal, have you tried inverting the crystals? I mean using the 13.4976 on the car and the 26.540 on the transmitter?

Anyway I can't understand HOW a 26.540 crystal gets into a 26.995 kit!!!!!

amazing!!!!

pdugue
2008.01.22, 07:55 AM
Hi fangel and thanks.

I understand for the engraved half-frequency of the Tx crystal but I'm really not sure that can match with 26.540 of the Rx. Unfortunately, I have no other 27mHz FM crystals to check that :(

I performed some new tests this morning:

- the voltage reading on the Tx is 10.4V with NiMh.
- to obtain some (poor) results, I must use the Tx antenna
- the 'palm of the hand' test does not work with the car (Rx) antenna (occasionally some small glitches but nothing more)
- the 'palm of the hand' test works only with the Tx antenna horizontally in the car axis front of the car
- the car responds when I catch with my fingers both the tip of the Tx antenna and the ring soldered at the end of the antenna wire (that doesn't work with the steel antenna).

I have uploaded a video (80mb) of the tests here: http://fanatech.free.fr/video/Iwaver_02M_test.MOV

pdugue
2008.01.22, 07:59 AM
Anyway I can't understand HOW a 26.540 crystal gets into a 26.995 kit!!!!! amazing!!!!
Hi leonen,

the same! ;)

I don't believe that can work better with crystals swapping so I don't try that.

leonen
2008.01.22, 08:50 AM
Hi leonen,

the same! ;)

I don't believe that can work better with crystals swapping so I don't try that.

Try It. It's how it should be. Rx freq is always smaller than Tx. Your kit evidently got mixed up.

You wont break anything.

pdugue
2008.01.22, 12:30 PM
Rx freq is always smaller than Tx.
Take a look at fangel post: the Tx crystal is engraved 13.4975 but that mean the real transmission frequency is 13.4975*2=26.950 that is greater than my Rx frequency that is 26.540 ;)

Anyway, I performed the swap test: nothing works anymore. The steering servo goes at enpoint at power on just like when you forget to power the Tx.

My conclusion: I think my crystals frequencies don't match but the crystal in the Tx is really a Tx compliant one and the crystal in the Rx is a Rx one so the're impossible to swap.

Hope it's only a crystal problem: in case of return, the shipping cost from France to Asia is more than 50.00$ :( Thanks french post office...

Regards

Pascal

fangel
2008.01.22, 08:57 PM
I saw your test, 10.4 is acutally not full.
When full it should reach up to 12V.
You actually should use both antenna for both RX and TX.
I'm not too sure about why this has happen, since I have tested the same set that you have. I could control the chassis without antenna on both the RX and TX, however I recommand everyone to install the RX and TX.
I could confirm that the RX and TX crystal that you have is a match (at least match enough to control it), I'm not sure what the real problem is, but you could try something, try using AM band and see if you could control it.

fangel
2008.01.22, 09:04 PM
I have asked the engineer about the band issue.
The reality is that the RX must be a bit smaller in frequency then the TX.
Our TX crystal is half because the radio system we use multipied it by 2.
All the radio system out there multipied their frenquency by 2 or 3. Our system is by 2.

You never see this happening to other brand of band crystal is because they either stick sticker on both TX and RX or they etch a fake matching frequency for the bands.

pdugue
2008.01.23, 05:38 AM
Hi fangel,

I understood before about the frequency doubling...

Take a look at fangel post: the Tx crystal is engraved 13.4975 but that mean the real transmission frequency is 13.4975*2=26.950...

What do you mean by 'Try using AM band...'? I have NO 27 AM transmitter.

I notice a strange thing yesterday evening: the car suddently began to works after ajusting the Tx tranmitter antenna lenght so I tried some different lenghts and I could see THE CAR WORKS FINE IF YOU FIND THE RIGHT ANTENNA LENGHT WITH THE RIGHT DISTANCE, THE RIGHT HIGH OF THE TX REGARDING THE CAR AND THE RIGHT ANTENNA ANGLE. Try to modify one of these parameters and nothing works anymore.

I've check the solders of the car board with a magnifier and I see nothing wrong. Maybe one of the crystals is defective or there is a 'cold' solder at the Tx antenna... Miu send me a new pair of crystals today: I could test the crystal issue for one week or two :(

Best regards

Pascal

pdugue
2008.01.23, 05:49 PM
Hi,

after many new tests I'm sure now that the crystals are well matched: when that works, that works really fine (good range - as far as it can be in my house, no glitches).

I performed some new tests this afternoon and I notice that was always the same way:

- power on the car
- power on the Tx => nothing work
- search for the failure by removing crystals, checking wires, measuring voltage on the PCB...
- at last, the car suddendly works well but I was not able to locate precisely the part that I touch when it happened :mad:

I noticed a very important thing each time that finally works: after running a bit, if I power off both the car and the Tx and I wait only 5 minutes or less before power on again, that works perfectly but when I wait for more (> 15mn) the failure is here.
Due to this new information, I made new tests:

TEST #1
- wait for 30mn after running
- power on (both) => nothing works except quick servo centering when powering
- don't touch anything except the Tx steering from time to time and wait
- some small servo moves occasionally, just like glitches
- after about 6mn, the steering suddenly works and I can run the car well

TEST #2
- wait for 5mn after running
- power on (both) => Works perfectly

TEST #3
- wait for 30mn after running
- power on Tx ONLY
- wait for 6mn...
- then power on CAR => nothing works

TEST #4
- wait for 30mn after running
- power on CAR ONLY
- wait for 6mn...
- then power on TX => Works perfectly

CONCLUSION
Except if the Rx PCB use valve technology like my old VOX guitar amplifier :p that kind of 'pre-heating' is definitively abnormal and it should be replaced by a good one.

So would you please let me know what to do for service it.

Best regards

fangel
2008.01.23, 08:17 PM
well after reading your post, I believe the crystal might not be the problem.
The problem seems to be on the RX side. Have you check your battery connection there?

Could it be your battery not outputting enough juice for the PCB? So "Run-in" time is require? Our PCB don't have any capacitor that require filling before it could run.

I'm not sure what the problem really is, but I believe it has something to do with current and electricity.

pdugue
2008.01.24, 04:22 AM
The problem seems to be on the RX side. Have you check your battery connection there?
Yes, I did it many times using a multimeter but I see nothing wrong.

All the tests were performed with fully charged NiMh and fresh alkalin battery also. If the problem was a power source issue, that mean that both NiMh and alkalyne batterys (freshly open blister!) were faulty: I don't really want to believe that but I'm going to perform a new test today with a new set of batterys... to be really sure.

EDIT

Well... the new tests give similar results than previous.

TEST #1
- new set of fresh alkaline batterys (voltage: 6.3V)
- power ON => doesn't work
- wait... => begin to works after 1 mn
- run 2 mn
- power OFF
- wait 30 mn
- power ON => doesn't work
- wait... => begin to works after 3-4 mn
- run 2 mn
- power OFF
- wait 30 mn
- power ON => doesn't work
- wait... => begin to works after 6 mn

... 5 cycles more: the time to wait before running stay around 6 mn.

TEST #2
- fully charged set of NiMh (voltage: 5.7V)

=> SAME RESULTS AS TEST #1

CONCLUSION

- at the first power ON, the 'idle' time is quite short (but it's still here!)
- when the voltage decrease, the 'idle' time became slightly longer but never exceed 6 mn (about).

2 different sets of fully fonctionnal and charged NiMh (tested in another Rc car) + 3 fresh sets of alkaline batterys: I can't believe the problem came from my power source and I'm sure now there is a faulty component on the PCB.

Because I'm so sure of that, I'm OK to buy a new PCB:
- if this one works, I send you back the faulty one for exchange (I keep it for spare)
- if that's not better with the new one hum... I probably make a mistake in my tests... and spending money for nothing.

I've take a look at Toyeast for the 27 FM PCB but I don't see it so can you tell me where I can find it.

Best regards

fangel
2008.01.24, 07:48 PM
I think I didn't make myself clear on the last post.
What I was referring to when I was talking about the power issue not from the battery directly but the power to the PCB.
This could be caused by faulty wire, bad connection from battery, etc...
I know you might have done this already, if this is true, then I think the problem is with the PCB, and we would like it back so we could show it to the factory and development team.
As for the replacement, I'll ask around if we still have any PCB in stock. Please wait for my replied. I'm quite sure that this is a unique case, since this problem was unheard of since I join this company with any of our PCB (previous model or current model)

I personally would like to investigate more on why it fail.

icelock
2008.01.24, 07:50 PM
its very hard to diagnose the problem without another car and tx.

you also have to consider that turning on or off affects the result of the test if tx and/or car has faulty/lose electrical connections.

from your tests you are able to run it completely (steering and throttle).

when the car runs, does it run fast or slow?
if it runs slow, battery is being discharged. it may be shorted sometimes (when turning on-off) causing the waiting time your experiencing to run it again.

you should verify battery juice after each tests (use flashlight).

pdugue
2008.01.25, 08:18 AM
Thanks Edmond, I stay tuned...


@icelock

You're right: 27mHz FM isn't a very common frequency in France and all my radio equipments are 41mHz PCM/PPM... so testing is not an easy task!

When the car finally begins to run, it runs very fast and I can drive till the batterys are flat (about 20 mn).
After each test, I control the battery voltage with digital multimeter ;)

Regards

pdugue
2008.01.26, 05:10 PM
I 've solved the #@!*! problem today!

That was an invisible 'cold' solder on the crystal connector of the PCB but... don't ask me to explain the reason why that always worked after waiting few minutes :rolleyes:

Hope this was the only April fool...

Best regards and thanks for your help.

fangel
2008.01.27, 08:45 PM
pdugue,
It's great that you have your chassis back up and running, I congratulate you on fixing the problem on your own. I will reflect this to the factory and make sure they check this in the future QC process. I'm fairly sure this is very uncommon, but it has to be prevented, since it is really hard to spot, well done again for spotting and solving the problem.

icelock
2008.01.31, 01:46 AM
don't ask me to explain the reason why that always worked after waiting few minutes
as i have previously said.. "you also have to consider that turning on or off affects the result of the test if tx and/or car has faulty/lose electrical connections."

regards and bash it hard:)

fangel
2008.01.31, 09:37 PM
I think Icelock is right, but then every little bit count to make sure the chassis performs correctly.