Aerogarden Model 100703 Need help fixing

Thread Starter

NBD925

Joined Apr 2, 2017
10
Hello everyone, I need a little help figuring out a problem with my "vintage" Aerogarden. What's an Aerogarden? It's a small hydroponic garden that can live on a shelf or countertop. I use it for herbs in the kitchen. Like food herbs, (I know some may be questioning)

I love this little garden and have had many a good meal with its product. But just this year I went to turn the Aerogarden on and nothing works.

Facts:
It plugs in to AC
The Florecent lights are AC
The water pump is AC
I get power to the unit
I get power to the lights but they do not turn on.
I do not have power to the pump or the front board or indicator lights.
I have tested the larger 2amp fuse on the board.
When plugged in the lights sometimes come on but for a micro second and turn off.
I tested a few things but still have no I idea what the issue is. I have included some pictures. IMG_2260.JPGIMG_2259.JPGIMG_2261.JPGIMG_2262.JPGIMG_0922.JPG

I have a second identical unit I can test but I'm at a loss for what may have gone out.
 

GopherT

Joined Nov 23, 2012
8,012
Check fuse "F2" close to the transformer. Use your volt meter on "diode" mode. Or ohms mode. It should beep in diode mode and read zero volts in resistance mode.
 

Thread Starter

NBD925

Joined Apr 2, 2017
10
Check fuse "F2" close to the transformer. Use your volt meter on "diode" mode. Or ohms mode. It should beep in diode mode and read zero volts in resistance mode.
I just checked the fuse at F2 both visually and with the multimeter and it is good.
 

Dodgydave

Joined Jun 22, 2012
9,304
What voltage have you got across C1, and the bridge rectifier BR1 input /output???

Looks like there are two opto triacs Moc3023....
 

Alec_t

Joined Sep 17, 2013
11,501
If you have an identical unit then, with the power off, do a series of continuity tests and Ohmmeter tests at corresponding points in the two units and compare readings. Where they differ will give a clue as to the fault location.
 

Thread Starter

NBD925

Joined Apr 2, 2017
10
I did some of that but I am still learning the art of electronics. One difference I did find was, one of the outputs at the ribbon connection on the right side of the board in pictures 2 and 3.

In Picture 1 you can see the back side of that ribbon connection and the 5 sets of pins soldered to the board. The second set (counting from the top down) (I think that was the set) had a different value than my test unit. I got a value of something like 32 on the good unit and way less on the bad unit.

I'll test it again tonight and get good values. I didn't write them down, it was a quick, I don't know what I'm doing but I'll touch these, type test.
 

Thread Starter

NBD925

Joined Apr 2, 2017
10
Ok, I tested the Cap at (C1)

Like I said before I have two Aerogardens, one working and one not working.

Working Aerogarden
Unplugged = .956 M ohm counting down
Plugged in = I got nothing testing ohms but switched to AC and got 209 mv AC

Non-working Aerogarden
Unplugged = 1.087 M ohm counting down
Plugged in = I got nothing testing ohms but switched to AC and got 37 mv AC

So something going on here!



I tested the rectifier at position BR1

Working Aerogarden
Input side unplugged = .942 M ohm
Output side unplugged = 2.8 ohm

Non-working Aerogarden
Input side unplugged = .938 M ohm
Output side unplugged = 2.8 ohm

Working Aerogarden
Input side plugged in = 208 mv AC
Output side plugged in = 15 V AC

Non-working Aerogarden
Input side plugged in = 35.4 mv AC
Output side plugged in = 15.18 V AC
 

Thread Starter

NBD925

Joined Apr 2, 2017
10
Ohm Tested the opto triac Moc3023 at position U1 right side of the board

There are three pairs of apposing connections.

Everything seems to check out except the middle connections.
The working Aerogarden shows 37.5 M ohms on the middle two pins.
The non working Aerogarden shows an open on the middle two pins.
 

Dodgydave

Joined Jun 22, 2012
9,304
DON'T TEST ON OHMS WHEN PLUGGED INTO MAINS!

you're getting DC coming out of the bridge rectifier which is good, the opto triacs will only work on AC, these switch on your lights or pump, they need a dc voltage to make them work, So i would compare voltage on pins 1,2 on the working one against the faulty one, i also noted there is a larger Triac (3 pin device black with metal tab), this could switch on a heavier load likely the pump.

Pin 1 will have a Dot or Notch on it.

QxcbW.jpg
 

Thread Starter

NBD925

Joined Apr 2, 2017
10
I will head the warning! The diagram of the MOC3020 helps. I see that I was testing it incorrectly. But why was I getting differences between the good and o working machine?

What do you make if the low reading on the non-working Cap at C1 and the low reading Redding in its rectifier? Also the different reading (although tested incorrectly) on that non working MOC3020?
 

Thread Starter

NBD925

Joined Apr 2, 2017
10
Anyone got an idea of what the next step might be? Is the part MOC3020 the bad actor in this circuit or should I be replacing or testing another component.
 

Thread Starter

NBD925

Joined Apr 2, 2017
10
Sorry about that! I'll get those values tonight after work.
I should have known better but I am not familiar with all the smaller component types and processes. It's been awhile since I've dug into electronic theory. Testing ohms while plugged in was an embarrassing mistake. I'm slowly going through a few of the old books and getting a couple basics back under my belt.
What I'm really having a hard time picturing is the flow through this circuit system.
 

Thread Starter

NBD925

Joined Apr 2, 2017
10
Ok the Cap at (C1) has a DC voltage of 19.58 v DC on the non working
18.89 v DC on the working

Rectifier at position (BR1) Nonworking
19.61 v DC +\- side
15.02 v AC ~~ opposite side

Working
18.86 v DC +\- side
15.03 v AC ~~ opposite side


Opto Triac position (U1)
Working model
Pin 1 and 2 test = 1.158 v DC
Pin 4 and 6 test = 10.2 mv AC counting down

Non working
Pin 1 and 2 test = .293 v DC
Pin 4 and 6 test = 190.2 mv AC almost steady but jumping slightly from 180's to 220'

Not sure what other test to make.
 
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