# Jebao Autodoser stopped working



## rebel (20 Jul 2017)

HI everyone,

My Jebao DP-4 has stopped working according the set program. Each individual pump can be manually activated. The Date/time/programs can be set without issues. The clock disappears after about a minute but the blue backlight still remains on.

I've tested with various combinations (pumps), date, time etc to no avail.

I got it off ebay from a seller who had been around since 2009. But now they have gone out of business. It is now 15 months old anyway so warranty may not be possible.

I have a multimeter and rudimentary soldering skills so wanted to ask anyone for any hints about diagnosing this issue.

Even some links to educate myself about this type of diagnosis would be appreacited.

Cheers!


----------



## ian_m (20 Jul 2017)

1. See if you can actually get inside the unit. Some units are welded, which means dremel to open with the chance you will bust it even more and it won't look nice once repaired.
2. Once inside, see if it smells burnt. If something has popped then most likely put unit in bin/recycling.
3. If all looks OK, unplug and re-plug every connector you can. 90% of the time with cheap(er) electronics it is connectors & mechanical issues that cause failure. Clean connectors with IPA/meths if you can.
4. Inspect all solder joints, especially the connectors. Dry joints due to improper assembly is a major cause of failure in cheap(er) electronics. If dry joint (cracked solder is possible) just resolder, preferably using plant killing environmentally unfriendly leaded solder that makes 100% reliable joints .
5. If not working after inspection/repair put in electronic recycling. Learn lesson, don't by cheap electronic from Ebay.
6. Study this article on 100% reliable dosing 
https://www.ukaps.org/forum/threads/how-to-use-a-plc-to-control-your-fish-tank.42993/


----------



## rebel (20 Jul 2017)

Hi @ian_m,

Thanks to your ideas I figured out the issue! In trying to take the unit apart, I noted that I had used a different power supply than the original. The original had the words 'doser' written on it. Then I looked online as to what power the original power suppply had been, given that I couldn't immediately locate it. IT appears that the original has 12V 3A and mine had only 12V 2A. I plugged in a more powerful supply 12V 6.6A (which I had lying around) and it started to work as per the program!!!

The 2A supply had been giving it barely power to run and I also noted the button response was sluggish, although present.

Many thanks for your ideas!

PS: Agree about 60:40 lead solder. That stuff is gooooood.  Just don't inhale too hard.....

Also I have already read your PLC article and understood about 10% of the actual words in that thread.


----------



## rebel (20 Jul 2017)

Also I use the doser to auto top up my tank (and add ferts) all in one go by diluting the ferts etc.


----------



## Humble_Reefer (14 May 2019)

rebel said:


> Hi @ian_m,
> 
> Thanks to your ideas I figured out the issue! In trying to take the unit apart, I noted that I had used a different power supply than the original. The original had the words 'doser' written on it. Then I looked online as to what power the original power suppply had been, given that I couldn't immediately locate it. IT appears that the original has 12V 3A and mine had only 12V 2A. I plugged in a more powerful supply 12V 6.6A (which I had lying around) and it started to work as per the program!!!
> 
> ...



Thank you!!! This worked for me too. Made an account just to say thanks. You saved me a lot of money and frustration. Much appreciated


----------



## rebel (15 May 2019)

Humble_Reefer said:


> Thank you!!! This worked for me too. Made an account just to say thanks. You saved me a lot of money and frustration. Much appreciated


You are welcome.

Make sure you hang around a bit also....


----------

