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Reset Mloader

Posted: Mon Jan 04, 2021 11:37 am
by sundgau
Hello,
I have 3 allcode out of 11 which cannot be programmed anymore; the red led no longer flashes. I can no longer program them either in USB or in Bluetooth. Is it about the 10uF reset capacitor C28? Can you confirm it to me?
Best regards and happy new year!
Bruno

Re: Reset Mloader

Posted: Mon Jan 04, 2021 12:00 pm
by Benj
Hi Bruno,

Have they been working ok? Might be worth trying them in a warm environment we have had reports that some units have problems programming when cold due to a capacitance component issue.

Are the batteries charging up ok?

Re: Reset Mloader

Posted: Mon Jan 04, 2021 1:37 pm
by sundgau
They have all worked fine since 2012-2017.
The recharge works and the BT connection too. I have just compared the signal at the terminals of the capacitor C28 of two allcodes and they seem identical: same rise time and maximum voltage.
I'll try to keep them warm! But this is not a lasting solution ... What are the capacitors that may need to be changed?

Re: Reset Mloader

Posted: Mon Jan 04, 2021 2:53 pm
by sundgau
Miracle of the beginning of the year ! Thank you Ben.
They all came back to life!
Now my students will get their allcode on the classroom radiator!
Is there a repair solution (change of very specific SMD electrochemical capacitors)?

Bruno

Re: Reset Mloader

Posted: Mon Jan 04, 2021 4:46 pm
by Benj
Hi Bruno,

You're very welcome,

I beleive the cap at fault is C13 and can be confirmed as touching the cap when not working should allow the robot to come to life.

Replacing this with a ceramic 1uF - 10uF 1206 should fix the problem for you.

Re: Reset Mloader

Posted: Fri Dec 24, 2021 9:04 am
by sundgau
Hi,

I just tested 2 repairs on two of my allcode.
The first one was to remove the 10uF smd C13 capacitor; this is very delicate and the tracks are very very fragile! You have to be very well equipped to do the maintenance. I damaged the track and I had to do a strap from the "Vcap" pin of the microcontroller!!!
The second solution is to place a tantalum capacitor of 1uF in parallel with the existing one
P_20211216_153722.jpg
P_20211216_153722.jpg (149.29 KiB) Viewed 3950 times
and to place a protection in 3d printing (onshape link: https://cad.onshape.com/documents/5c31a ... ebb788f1a5) on the whole.
Screen Shot 12-24-21 at 08.51 AM.JPG
Screen Shot 12-24-21 at 08.51 AM.JPG (20.95 KiB) Viewed 3950 times
Screen Shot 12-24-21 at 09.02 AM.JPG
Screen Shot 12-24-21 at 09.02 AM.JPG (42.63 KiB) Viewed 3950 times
Happy christmas to all.
Bruno