Thank you though, it was worth a try! Tomorrow I plan on replacing a load of components, I might as well. Can someone please advise which ones are likely to effect?
Thank you though, it was worth a try! Tomorrow I plan on replacing a load of components, I might as well. Can someone please advise which ones are likely to effect?
wow thank you, I am no electrical engineer though and I don't know where to start with that schematic, can you please elaborate?
Kind Regards
Start in page 41 of the schematic(charging ic) the ic number is PU11. Look for pin 1, you will know by the white dot next to the pin. Once you locate pin 1 start counting counter clockwise find pin 2 and 14.
PU11
pin 2= check voltage should be 3.3v (charge enable pin). If there's no voltage in pin 2 look for KBC U33(page 33) look for pin 102(charge enable pin) if there's voltage replace PR155.
pin 14= check voltage with battery should be 12v(battery charging pin). If there's no voltage in pin 14, unplug battery and charger and check PR2(diode test).
Start in page 41 of the schematic(charging ic) the ic number is PU11. Look for pin 1, you will know by the white dot next to the pin. Once you locate pin 1 start counting counter clockwise find pin 2 and 14.
PU11
pin 2= check voltage should be 3.3v (charge enable pin). If there's no voltage in pin 2 look for KBC U33(page 33) look for pin 102(charge enable pin) if there's voltage replace PR155.
pin 14= check voltage with battery should be 12v(battery charging pin). If there's no voltage in pin 14, unplug battery and charger and check PR2(diode test).
Your help so far is very appreciated, thank you.
So far - with ac adapter plugged in and NO battery
PU11 PIN 2 is 3.3V
PU11 PIN 14 is 19V (should be 12V!)
Have not looked at U33 (I assume I don't need to because PU11 PIN 2 is 3.3V?)
Should this be 3.3V even with NO battery inserted?
What should I do now? PR2 looks more like a fuse although I don't really know. How do I test this? I tried test probes each way and had 0 ohms on both motherboards.
An electrical engineer at work swapped the PU11 IC's around and still the result was the same. Non working motherboard was able to charge and working motherboard cycles between charging and not charging.
On swapping back, both motherboards are playing up, the LED flickers now and the U33 gets hot. I think there is either a short or missing contact.. I will look in to this tomorrow
Thank you though, it was worth a try! Tomorrow I plan on replacing a load of components, I might as well. Can someone please advise which ones are likely to effect?
So far - with ac adapter plugged in and NO battery
PU11 PIN 2 is 3.3V
PU11 PIN 14 is 19V (should be 12V!)
Have not looked at U33 (I assume I don't need to because PU11 PIN 2 is 3.3V?)
Should this be 3.3V even with NO battery inserted?
What should I do now? PR2 looks more like a fuse although I don't really know. How do I test this? I tried test probes each way and had 0 ohms on both motherboards.
Thanks!
on diode it will show 0 and on ohm it should show 2 to 3 ohms to be a good fuse if its marked f on board...
An electrical engineer at work swapped the PU11 IC's around and still the result was the same. Non working motherboard was able to charge and working motherboard cycles between charging and not charging.
On swapping back, both motherboards are playing up, the LED flickers now and the U33 gets hot. I think there is either a short or missing contact.. I will look in to this tomorrow
Any more suggestions?
Kind Regards
check all connections...now that you have a schematic you can check the charge system... since both boards are doing same thing that schematic is all you got for any ideas to what it should be....let me study it and i will throw some idea's your way....
Thanks! I still think it could be PU11, what else could cause the 19V on pin 14? I think it wasn't soldered in place properly, the IC doesn't have legs, just contacts.
by the way is PR155 a diode? on both motherboards I am getting 100k-ohms each way on this.
I also checked some voltages around U33, getting some 3.33V on both motherboards, but PR155 on the charing board is 3.33V and on the non-charging board is 3.03V
Thanks! I still think it could be PU11, what else could cause the 19V on pin 14? I think it wasn't soldered in place properly, the IC doesn't have legs, just contacts.
Yes PU11 is a QFNL (quad flat no leads)and some of the pins are shorted so don't keep powering it up or you're going to make it worst, you will need to resoldered it. Also PR155 is a resistor and is fine if you're getting 100kohms.
Also check PQ15 I think is bad that's why you're getting 19v on that bus line. PQ15 is an Nchannel mosfet so place DMM in diode mode and place neg- prove on pin 8 and pos+ prove on pin 1, you should get around 500ohms. Now flip the proves aorund and you should get no reading. If you do get a reading replace it.
what does PQ15 refer to? I have attached a picture, I found the text but can't really see what it points to.. I think it is one of those legless squares, which I will not be able to test, but I can try to replace..
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