Spectra S1+ Breast pump - No suction

[caphair]

Re: Spectra S1+ Breast pump - No suction

Ok I took the cover off the pump to reveal that it works off 12vdc. Applied 12vdc and it functions fine. So definitely a circuitry issue.

Noticed two test points. One measures 5v the other TP2 shown in the pic on the pump side of the circuit measures 11v. But at the pump connections I get 0v.

On Q7 I measure battery voltage 11-11.34v (jumps to 11.34 then back to 11v as the little metal box cycles on/off) on gate and all 3 source pins. So this should be turning the mosfet on correct? Vg-Vs 11v-11v = 0v (could be wrong I often struggle remembering how mosfets work)
Nothing measured on the drain pins.

I think Q7 is shorted Gate to Source I measure .978v in diode mode both ways

Quick search shows this is a 30v P-Channel Mosfet in SOP 8-package


Can’t seem to find a replacement. Could someone help me with that? Thanks

[momaka]

Re: Spectra S1+ Breast pump - No suction

Should I use a dc source and slowly increase the voltage to see if it'll turn on? I'm not sure how much voltage is needed (not labeled anywhere) if I exceed the voltage would it cause any damage?

Well, that is the question: does the pump use DC or not? And voltage requirement.

To answer those, have a look on the PCB to see if it reveals any clues. If the black wire (negative terminal?) going to the pump is connected to ground, and the red wire to a single MOSFET or (or other switching device), then the pump is most likely DC-driven... though it could also be pulsed DC, not knowing exactly what is inside.

We also know the absolute maximum voltage is imposed by that of the battery and AC adapter - i.e. 12V and no more.

Also when turned on this valve? Clicks. I'm guessing created the suction from the pump. At the pump connector I measure 0v

Perhaps get the instruction manual and see how it's supposed to operate. Maybe if not attached properly to the body, the pump won't run??

[caphair]

Re: Spectra S1+ Breast pump - No suction

Does the pump use a simple DC motor? (Looks like it, as it's only a 2-wire connector?) If so, does it turn when you power it with an external power source. Surely the first step would be to make sure the pump motor is OK... and if yes, then move on to the circuits.

Should I use a dc source and slowly increase the voltage to see if it'll turn on? I'm not sure how much voltage is needed (not labeled anywhere) if I exceed the voltage would it cause any damage?

Also when turned on this valve? Clicks. I'm guessing created the suction from the pump. At the pump connector I measure 0v

[momaka]

Re: Spectra S1+ Breast pump - No suction

Does the pump use a simple DC motor? (Looks like it, as it's only a 2-wire connector?) If so, does it turn when you power it with an external power source. Surely the first step would be to make sure the pump motor is OK... and if yes, then move on to the circuits.

[caphair]

Re: Spectra S1+ Breast pump - No suction

wow - talk about scam.
99% of the circuitry looks like it's just for a graphic display.

Lol has a massage feature and controls for suction. Probably more not too sure.

What should I investigate for the pump?

[stj]

Re: Spectra S1+ Breast pump - No suction

wow - talk about scam.
99% of the circuitry looks like it's just for a graphic display.

[caphair]

Trying to fix this for someone. They said water got into to it and it worked for a day then suddenly no more suction from the pump.

There isn’t any visible liquid/corrosion on the circuit board. Display works and responds to control settings, but the suction pump never turns on. The yellow connector goes to the pump

Have no idea about how this is supposed to work so looking for any advice on where to start/what to look for.