SL 45 is not power on

[dnb]

Hi All,

I am a new user here. I have to repair old phone SL 45.

It does not power on or no indication while charging, COMPLETLY DEAD. I did not try to FLASH it or anything. This is a HARDWARE Failure.

My freind gave that unit and I don't know what happend.

But when I pluged to AC Adaptor Battery is getting cahrged, but NO LEDs or CHARGING INDICATION. (I discharged battery total and used a multimeter after charging)

I checked every where in PCB for physical damage NO DAMAGE FOUND.

Hey Genies can you give me some hints,

Thanks,

DNB
I had post this in other tread sorry that was a mistake)

[Chris02]

Is the battery ok?? Try another, 100% working batterie first!

[dnb]

I got new battery with full charge. I put that not working. Somebody had post connector pinouts. According to that there should be a voltage between PIN 1 to PIN 4 (For Accessories) but 0.0 Volage there.

Battery has 3.5V and I put 2.8V/ 0.5A tourch bulb on battery it works, that mean good battery no?

This unit is used by somebody else, he said something like "he used a C35 battery to test the unit and he said it was not working"

May be he has put the put polarity (+ and -) wrongly, If so where will be damaged and what I should try, give me chip numbers I am new technician.

If any idias please let me know I am being dead

DNB

[bestman]

since you have begin with flashing your phone , it is diffcuit to address this application.
you have to get a new battery and continue flsahing your phone.

bestman

[dnb]

I got a new battery as you said but I tried as I know every way but did not work

I did not flash my phone yet sir and it is not responding to Winswup also.

Thanks

[hightemp]

if you got a microscope try to check the contact pad for power ON button. maybe a broken line due to oxidation. or try to use a external power supply and apply the rated voltage of SL45 battery to your phone then press Power ON button and if ammeter does not move upon pressing the power ON button then there's something wrong with power up line.

[dnb]

I used an external power supply with 3.8V and pressed power on button. Does not move my ammeter.

Power on button contacts are clean and working, I checked with a multimeter.

Any other idias please?

[hightemp]

pls check contact pads for power ON button under microscope maybe a broken trace.

[bestman]

1. try check battery level again.
2. check battery connector again.
3. check your phone contact pad again.
4. check chraging areas.
5. you can clean your phone board for broken lines on board .


bestman.

[dnb]

I check them well but nothing wrong there.

I got this from my friend.

Initially he had no battery to check this unit (whether it is working or not) So he had tried to use C35 battery to test the phone.

May be he has put the battery in wrong side (“+” and “-“), Becase the PINs are upside down. So he may did that tring to put the battery pins whereever posible.

If so what IC and Parts will damage. Tell me what IC and parts Numbers to check

I am not an expert, a univercity electronic student, Give me part numbers please.

If any other idia please give me.

[yiourkas]

Some ideas:

1.Check the unit's keyboard pins.
That orange circuit is very delicate and may be damaged with a single drop of water.

2.You said that if you plug the AC adaptor the phones starts to charge. So
a) I don't think it's a battery failure
b) No Leds or charging indication may mean that your screen is damaged, or the pins don't make a good contact. Try cleaning them.
c) It may be just a phone amp failure, so it cannot provide power to the other ICs

3. Disassamble your phone. remove front cover and re assemble it without the front cover, keyboard and screen. Use some tape or something to keep the battery in place. DO NOT PLUG THE AC ADAPTOR (it enables illumination, and if not leds are found, then all parallely connected circuits will get higher voltages) . Try getting some voltages around the amp

[dnb]

Thanks freind but I don't know the amp IC number, please give me that.