I have an STM32 Primer, the first version. I had it laying laying around for a long time. When I wanted to use it again, the Batteries are empty which is understandable but when I wanted to plug it in to so charging and to test it's operation, by pressing on the button, it won't turn on. Is it possible to replace the batteries with new ones or with an external power adapter? Are there any tipps and recommendations?
The STM32-Primer (first one) was equipped with a poor quality battery. And there was no actual battery charger component on the device. You can modify your unit if you wish, but switching to a more recent Primer such as the Open4/EvoPrimer would be much easier.
@Bruno I would love to but im a student in highschool and already spent lots of money on my home lab.
@RWM I would love to, but I have only 1 try @ this so if you could give me precise instructions of how to do this would be great. Cant I simply cut the batteries out with a wirecutter and connect the poles to a usb cable?
You can't connect poles to USB cable. Firstly, you should remove jumper near batteries to disconnect them and check whether Primer turns on. If so, you should remove old batteries (desolder) and connect new ones (for example 2.4V replacement pack for cordless phone). As I haven't Primer, I don't know how batteries are mounted. Do you have a picture?
When removing the jumper, which would bypass the batteries, still wouldn't turn on the device. I made some pictures of the batteries and of the Controller AR6T1220QY, the controllers has some wierd blue stuff on the pins. Take a look.
Batteries can be replaced by regular AAA NiMH cells with solder tabs or, if these aren't available, replacement 2.4V AAA battery pack for wireless phone.
Blue stuff looks bad. I think there is a problem. AR controller is Rlink debugger circuit. Jumper disconnects battery, but there is a bypass (diode D11 on schematic http://www.stm32circle.com/resources/do … er_1_2.PDF) and Primer should work without battery. As it doesn't, there should be a problem with electronics. Can you measure voltages in circuit?
Looks like the batteries have been leaking, and can not be used anymore. You must remove the blue stuff, and check if PCB wiring is corroded underneath. If so, that may have caused the PRIMER to die. If you can make it all look clean again, you'll have to replace the batteries with new ones. Cutting the old ones out, and soldering a new pair should do the job. Note, make sure the new batteries have decent charge. At least on the EVOPRIMER, if the battery voltage is to low, it refuses to charge: a minimal voltage is required.
I can measure the voltages of the circuit, u'll have to tell me at what point should I measure. As far as I understand from the documentation, that jumper only tells the current where to go. If it is not set then it will not charge the batteries, so why do I need to bypass the Diode D11? I took out the jumper and measured the voltage that is at D11, it is at 35mV and steadily rising.
You don't need to bypass the diode D11. This diode is a bypass for supply current to supply Primer without batteries. Jumper only connect batteries to circuit, so acts as a switch.
"Underneath" means "under the controller IC". There can be corrosion of traces/vias/solder joints on PCB under the controller IC.
@RWM: I took an lold toothbruch and got 99.9% of that blue stuff of it. Removing the IC is difficult for me since I don't have the proper desolderung equipment for it. The voltages of the meantioned capacitors are the following: C8: 3,63 V C18: 0V C19: 1,12V C39: 3,59V
It seems that Q5 doesn't open and power isn't supplied to VCC3 (processor, display etc.). It is controlled by U9. Can you measure voltages on R41 and R21 when bushbutton is pressed and not?
D3: 92 mV And D9 is some kind of transistor (3 legger) how do u measure that? I measured the middle the one that is single on one side with one if the 2 on the other side, one measurement gave me 2.8V and the other gave me ~64mV and the 2 on the same side gave me 2.8V
Sorry, I haven't written clearly. D9 is dual diode (2 diodes in one case), common cathode connected to push button SW1. Could you measure voltages ground-related (negative voltmeter input connected to negative battery pole) on D9 cathode (side with one pin), then on D3 cathode and R6 with pressed button SW1 and not.
ok i measured both batterypoles just to be on the safe side. There is one over D3 which doesn't give me no value whether I push the button or not. And the one over D9 where I measured around 760mV when not pushing the button and 700mV when it is pushed.
If there is a voltage on C8 and nothing on D3 cathode, this diode can be faulty. However, in previous post you have written that voltage across D3 is 92 mV.
You can try to connect C39 to R21 with small resistor (1kohm) to check if power switch Q5 will turn on.
Hi, sorry for being away for a long time. C39(is at one corner of the screen) and R21(is at another corner of a screen where the switch is) are far away, so when saying "small resistor" means wire?
