A family member asked for help fixing one of those decorative indoor water fountains. The symptoms were "it doesn't work." Anyways, aside from the possibility of simply a bad pump, I'm looking at the electronics. Can anyone help me identify the two components below? The disc (which reminds me of a ultrasonic nebulizer, but why?) and what might reside under the grey blob? : )
Thanks!!!

 

Looks like a loudspeaker and a custom made IC under the blob which will be next to impossible to repair/replaced.

 

The disk could be a microphone. Is the fountain supposed to respond to sound?
The grey blob is hiding an IC called a 'chip-on-board'.

 

Fresh solder on everything, then start a more detailed diagnostics.

 

Looks like a loudspeaker and a custom made IC under the blob which will be next to impossible to repair/replaced.

The circuit itself is pretty basic. Easily rebuilt with extra components I have, EXCEPT for the mystery chip! Anybody have an idea what it may be?...I also thought the other component to be a speaker possibly, but the owner said nothing about sound ha ha.

 

The disk could be a microphone. Is the fountain supposed to respond to sound?
The grey blob is hiding an IC called a 'chip-on-board'.

Hmmmm another possibility. I need to ask the owner a couple of questions

 

Fresh solder on everything, then start a more detailed diagnostics.

I may go that route now that most people seem to think the chip is impossible to replace/identify...Initially I just drew the circuit and was going to just replace the components and put them on my own little PCB.

 

The circuit itself is pretty basic. Easily rebuilt with extra components I have, EXCEPT for the mystery chip! Anybody have an idea what it may be?...I also thought the other component to be a speaker possibly, but the owner said nothing about sound ha ha.

Look at the traces leading away from the chip. It looks like a 6-pin chip. These are also called 'blob-chips'. Once you identify power-pins, see if you can get an idea what the other pins are for. Normally, it's going to fall into a couple of categories- things that deal with A/C power (like SCRs, or bridges), or it will be a micro-controller, like an Atmel tiny or something like that. If you can identify most of the pins, see if it matches a through-hole equivalent for one of the others, and compare that against the schematic you make from the traces an what it's supposed to do.

 

Look at the traces leading away from the chip. It looks like a 6-pin chip. These are also called 'blob-chips'. Once you identify power-pins, see if you can get an idea what the other pins are for. Normally, it's going to fall into a couple of categories- things that deal with A/C power (like SCRs, or bridges), or it will be a micro-controller, like an Atmel tiny or something like that. If you can identify most of the pins, see if it matches a through-hole equivalent for one of the others, and compare that against the schematic you make from the traces an what it's supposed to do.

Thanks. I did a rough sketch last night. I'll probably redo it on the PC to make it more readable and accurate. I have to say you can learn a lot just by sketching the traces and components. A necessity in reverse engineering I suppose. After I do a semi decent schematic I may post it on here. I'm pretty sure at this point that mystery component was a speaker for some sound effects. Honestly, I'd rather leave that out. All I'm after is getting the water flowing. Maybe I can leave the chip out entirely. Perhaps that's why it's in there. Anyways, thank you for your input and I'll post again in my down time.

 

So, I decided to try EasyEDA for the first time on this sketch. The schematic is a snapshot from my phone. I don't know anything about this program, I was waiting for someone to charge me something :/
So I took a snapshot until I learn more.
Anyways, based on this circuit and the mystery chip, I'm assuming it is related to just sound? If so I don't care about that. Just want to get the water flowing again. That's it. Does anyone have input on adjusting this schematic for that purpose only? I'm going to look at it in more detail as well, try to figure out how it works etc. My brain hurts right now though

 

Forgot the pic.

 

It looks like one end of the pump is connected to +3 volts and the other is connected to the + side of C@ (which seems odd, but never mind). Lift that lead and temporary jump it to the - lead. If it works, you probably don't need the circuit; if it doesn't work than the pump is bad.

 

It can't work as drawn

 

It can't work as drawn

Can you give me a clue?...Ok, based on your comment and white haired novice I will take a second look. Keep in mind I've had to really do some digging into this thing (with a mini grinder) As you know, many products from China are designed for no entry. ... I kind of enjoy the process of defeating it though. I suppose I'm a bit weird like that.

 

Need to see more then you have shown.
Picture how it was all installed a full top and bottom of the circuit board.

The disk is to tell if there is water in the tank so you don't run the pump dry more then likely.

The motor will not power as you show it

Q1 is a short need's to be something like this I left emf diode out because lot's of these things use part with one made into the transistor. I have a bunch of npn that switched small motor after finding datasheet showed diode made into part.

 

It doesn't make sense if Q1 is a NPN BJT. What is the purpose of connecting the collector and emitter directly across the battery terminals?

The tracing on Q2 and Q3 might be wrong too. The footprint of C945 is different from that of 2N2222 or BC547...


Allen

 

I redrawn your schematic and it is now easier to see what are the unreasonable areas.

 

I do not think Q1 should be connected directly across the battery. The pump can never be powered up the way it is shown in the schematic in post #17. As there are no switches or push buttons could it be that LS1 is being used as a microphone so the unit could be triggered by sound ?

Les.

 

Need to see more then you have shown.
Picture how it was all installed a full top and bottom of the circuit board.

The disk is to tell if there is water in the tank so you don't run the pump dry more then likely.

The motor will not power as you show it

Q1 is a short need's to be something like this I left emf diode out because lot's of these things use part with one made into the transistor. I have a bunch of npn that switched small motor after finding datasheet showed diode made into part.
View attachment 143725

Thanks for taking the time to do the drawing, much appreciated. As far as the disc goes what might this component be called? How does it determine water level/pressure? I'll try to get back to this project in more detail as time allows. The start of the new work week sucks up all my free time.

 

I redrawn your schematic and it is now easier to see what are the unreasonable areas.

View attachment 143738

Thanks as well for taking the time to do the schematic. I agree, something isn't right. I need to go back and carefully draw again and see where I got off. They covered everything in the worst hot glue I've seen and I had to do a bit of damage(cutting,scraping) to even get a glimpse. That's why I was just more interested in rebuilding it all together after I know I have something workable- why I'm consulting the pros here at AAC
i'll be back to this thread.