harp I decided to do a reflow of a couple of areas containing numerous components and have fixed the issue. Must have been a broken solder joint that I didn't spot under the scope.
Thank you for all your help...
Techie_hobby1
Senior Member
Last Activity: 09-03-2026, 04:43 AM
Joined: 02-24-2023
Location: London
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harp Apologies I missed a little bit of your response, there is no sensor on the actual wires that go to the type K plug. It is just 2 short leads and the type K plug at ht eother end (approx 10cm length)...Leave a comment:
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And just incase I really have missed read the pcb, here is a close up of the entire board in stages.. but I am fairly sure I have it drawn correctly...
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R_J That is spot on, and now I understand the logic with silkscreen notations (although I am guessing this is not always the case) I always wondered why some SOT23 are labelled as Q1, U1 and even D1, obviously D1 would be a Diode, and Q1 should be a Transistor, but I just thought U1 for a SOT23 is just the company using a U and instad of the D or Q.. now it seems to make a bit more sense..
harp in answer to your question, no I do not trace while it is powered, and use Continuity mode to trace pretty much most of the circuit, however I had to use resistance mode to identify the button traces...Leave a comment:
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stj yes these are definitely a bit of a challenge...Leave a comment:
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harp That is an awesome find thank you. The DMF is spot on.
In regard to U1AW marking, it is identified as U2.
Now that you have identified the DMF that tells me that the Drain (connected to Bat +) outputs 4.7v, and source outputs 4.7v., since Gate is connected to GND…. Then from Source this connects into the Collector of 1UAW NPN transistor.
The Base is tied to GND, but the Emitter is only outputting 2.7v.
I am pretty sure the MSP340F4250 requires 3.3v to work properly, since the switch FPC will drop a small amount of voltage..(albeit not a lot)
So that is why...Leave a comment:
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Help with this component please?
I am really struggling to identify this one. any help would be much appreciated...
Note I did create a different post yesterday, however I think I went to much off the subject matter, and it got thrown into a duff post... -
I have attempted to produce a schematic in hope this will answer some questions - and also taken a couple of images of the 2 essential components.
...Leave a comment:
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I am in the process of troubleshooting a Therma 1 Thermometer and need help identifying 3 components please
The fault at present when it switches on reads Error. Sometimes the screen shows a temperature that quickly cycles (drops) to a negative value before entering Error mode.
First component is in SOT23 package and has marking code DMF with a D1 (or 01) written sideways..
I think it might be a P-Ch Mosfet since...
Battery +ve is directly connected to Pin 3 (top single pin), Pin 1 (bottom left pin) connects to GND, and Pin 2 (bottom right pin) connects into the 2nd compoent that I am unable to identify. Both Pin 1 and Pin2 connect through a large (0805) ceramic capacitor.... -
andrewsawesomr Thank you for the image on the white ceramic capacitors
I am still struggling to locate the violet ones still.
In regard to your side note question.. yes he used to manufacture Pagers. So a lot of these components do contain RF values, although he did leave a mix of components behind that he had built up over the years.Leave a comment:
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Help identifying a couple of components please
Brief story.. I have recently been passed down a huge selection of components from a friend who's father recently passed away.
I am slowly going through the supply and have come across a couple of unknowns so far.
1)The first one is a packet that just has a hand written "partial" part number of HP7419 - they look like ceramic type capacitors however, these are white all the way around them in an 0805 footprint, and have a value of 3pF written on the packet. I have checked this with my LCR Meter and it confirms to that value, but I am stumped with what type they could... -
How about a Diode marked as 02 - would that suffice and protect the circuit values
I just realised it isn’t BAT50 as they were for a different project altogether...Leave a comment:
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My normal camera setup is in process of being relocated, so at the moment it’s the best Incan get.
I am in the process of changing the other connector which is why it is not sitting in position.
but hopefully you can see the pcbLeave a comment:
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It’s a Diode question rather than a Cap one
So I have a BAT14-098 (Schotky Diode (1 of 2) that has gone bad. It is just protecting reverse current 5V supply, for an E-Scooter display panel.
Unfortunately, I cannot locate one of these components locally and need to get the repair done and returned to service.
My question though, could I put a BAT50 in its place as I have a few of these sitting on old PCB’s that are being used as doner boards -
truclacicr stj Thank you so much, this will give me a better understanding of what is going on with this circuit..
I will also take some time to go back (trace back) all the traces, connections and components to ensure that I have not made a silly error.. this will hopefully rule out any head scratching from both yours STJ's and anyone else who is looking at this.
I think I might have rushed this one a little too quickly in the hope that I could have fixed it quickly for my friend.
She has been without the solar fountain for some time now so I might take some...Leave a comment:
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truclacicr stj
I stand corrected it is definitely not a CN3302 because after looking at the typical applications it mentions MOSFET's in the design which we know these are NPN and PNP transistors and GND is Pin 4 on this IC
I have had to put this one aside for a few days as I have been given something else to take a look at..but would really be grateful of any further assistance. I have been searching through those IC's and none of the pin configurations seem to match up
I had a light bulb moment where I thought the IC might just have been a Boost Regulator which can be...Leave a comment:
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truclacicr Yes that is correct, the DC + & DC- are what the pump motor connects to.
truclacicr stj - so am I right in thinking that these Batteries don't actually charge up at all??
Ideally this circuit needs altering so that it can charge the batteries during the sunlight, and then once charged when sunlight switches to sunset have the batteries take over and power the circuit for as long as they can.
stj - re NiMh cells, do they require a BMS like Li-Ion cells require.
So we are still unsure what the IC is.. I took a look at some...Leave a comment:
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stjtruclacicr
im still having a few difficulties with this circuit.
i have tried reaching to other sites but they too are not coming back with anything useful.
i swapped out the battery pack for 2 x 3500mAh cells and it seemed to work for about a week, but now it seems like they are not charging.
How would be a good way to test that these are actually charging with the sun???
Regarding that 8 pin IC..still unsure what it is and how I can identify it???...Leave a comment:
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adamok7 perfect thank you.. and from that I have been able to locate the correct datasheet 8252...Leave a comment:
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