Panasonic EB-GD35 turns off while newtork searching - GSM-Forum

Dmitrii · 11-04-2005, 17:40

Hi All!
I have problem with Panasonic EB-GD35. It turns off while network searching. I supplied it from DC source with the nominal battery voltage 3.6V. The problem remained. When voltage was higher than 3.8V, it worked well. I connected capacitor with 4700uF in parallel with battery connectors, and it eliminated this effect, all works OK. But this is not best solution, because capacitor has an enough big size, and, newertheless, the phone worked well before without capacitor. The oscilloscope shows, that a voltage ripple is present on battery connectors about ~0.5..0.6V when network is searching (with capacitor connected). What could cause this phenomenon?
Did anybody have this problem?
Dmitrii.

debeliamark · 11-05-2005, 06:50

at least full charged battery voltage is grow up to 4,2 V - mean 3,6 V is discharged battery - so when you have placed capacitor with big value you have better internal resistance for line from battery (or external supply) to a biggest consumator - FR PA - the hint is very easy - try to change battery with new one with internal resistance not more that 150 mOhm - if still not work well then clean path from battery to PA, also check for some L-s that not work well on high frequency, and if still is not OK, then check consumprion in active state - if go over 300 - 350 mA - then PA or Antena switch must be changed (4.0 - 4,2V supplay) ...

mehta · 11-05-2005, 07:10

change pa 8103 sirrrrrrrrrrrrrrrrrrrrrrrrrrr

Dmitrii · 11-05-2005, 21:26

Thanks.

To Debeliamark: by the phone service manual the voltage 4.2V is considered as a ?battery high voltage? and the voltage 3.2V as a ?battery low voltage?. The value of 3.6V is considered as nominal (so, this voltage is written on battery label). I will check the phone current. Probably, the problem with PA or Ant. Switch.

To Mehta: I think the same way as well.

Dmitrii · 11-09-2005, 15:41

The peak DC current is 200mA at network searching, and 250mA at making call. Is this normal value?

debeliamark · 11-10-2005, 05:42

Yes - good working phone - 250 mA on conection is OK - no need to change anything in TX circuit...

Dmitrii · 11-11-2005, 17:56

Can this problem be evoked by software fault, for example, incorrect determining of battery low voltage? Maybe, I need to reflash phone?

gurukripa1982 · 01-19-2006, 14:05

Quote:

Originally Posted by Dmitrii

Hi All!
I have problem with Panasonic EB-GD35. It turns off while network searching. I supplied it from DC source with the nominal battery voltage 3.6V. The problem remained. When voltage was higher than 3.8V, it worked well. I connected capacitor with 4700uF in parallel with battery connectors, and it eliminated this effect, all works OK. But this is not best solution, because capacitor has an enough big size, and, newertheless, the phone worked well before without capacitor. The oscilloscope shows, that a voltage ripple is present on battery connectors about ~0.5..0.6V when network is searching (with capacitor connected). What could cause this phenomenon?
Did anybody have this problem?
Dmitrii.

i remove this fault by changing pfo

11-04-2005, 17:40	#1 (permalink)
Dmitrii Junior Member Join Date: Nov 2005 Location: Ukraine, Donetsk Age: 45 Posts: 4 Member: 196862 Status: Offline Thanks Meter: 0	Panasonic EB-GD35 turns off while network searching Hi All! I have problem with Panasonic EB-GD35. It turns off while network searching. I supplied it from DC source with the nominal battery voltage 3.6V. The problem remained. When voltage was higher than 3.8V, it worked well. I connected capacitor with 4700uF in parallel with battery connectors, and it eliminated this effect, all works OK. But this is not best solution, because capacitor has an enough big size, and, newertheless, the phone worked well before without capacitor. The oscilloscope shows, that a voltage ripple is present on battery connectors about ~0.5..0.6V when network is searching (with capacitor connected). What could cause this phenomenon? Did anybody have this problem? Dmitrii. Last edited by Dmitrii; 11-04-2005 at 18:16.

11-05-2005, 21:26	#4 (permalink)
Dmitrii Junior Member Join Date: Nov 2005 Location: Ukraine, Donetsk Age: 45 Posts: 4 Member: 196862 Status: Offline Thanks Meter: 0	Thanks Thanks. To Debeliamark: by the phone service manual the voltage 4.2V is considered as a ?battery high voltage? and the voltage 3.2V as a ?battery low voltage?. The value of 3.6V is considered as nominal (so, this voltage is written on battery label). I will check the phone current. Probably, the problem with PA or Ant. Switch. To Mehta: I think the same way as well.

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11-05-2005, 06:50	#2 (permalink)
debeliamark No Life Poster Join Date: May 2001 Location: Bulgaria Age: 56 Posts: 4,796 Member: 4627 Status: Offline Sonork: 57528:debeliamark Thanks Meter: 1,034	at least full charged battery voltage is grow up to 4,2 V - mean 3,6 V is discharged battery - so when you have placed capacitor with big value you have better internal resistance for line from battery (or external supply) to a biggest consumator - FR PA - the hint is very easy - try to change battery with new one with internal resistance not more that 150 mOhm - if still not work well then clean path from battery to PA, also check for some L-s that not work well on high frequency, and if still is not OK, then check consumprion in active state - if go over 300 - 350 mA - then PA or Antena switch must be changed (4.0 - 4,2V supplay) ...

11-05-2005, 07:10	#3 (permalink)
mehta Freak Poster Join Date: Jan 2005 Location: india Posts: 399 Member: 102598 Status: Offline Thanks Meter: 68	change pa 8103 sirrrrrrrrrrrrrrrrrrrrrrrrrrr

11-09-2005, 15:41	#5 (permalink)
Dmitrii Junior Member Join Date: Nov 2005 Location: Ukraine, Donetsk Age: 45 Posts: 4 Member: 196862 Status: Offline Thanks Meter: 0	The peak DC current is 200mA at network searching, and 250mA at making call. Is this normal value?

11-10-2005, 05:42	#6 (permalink)
debeliamark No Life Poster Join Date: May 2001 Location: Bulgaria Age: 56 Posts: 4,796 Member: 4627 Status: Offline Sonork: 57528:debeliamark Thanks Meter: 1,034	Yes - good working phone - 250 mA on conection is OK - no need to change anything in TX circuit...

11-11-2005, 17:56	#7 (permalink)
Dmitrii Junior Member Join Date: Nov 2005 Location: Ukraine, Donetsk Age: 45 Posts: 4 Member: 196862 Status: Offline Thanks Meter: 0	Can this problem be evoked by software fault, for example, incorrect determining of battery low voltage? Maybe, I need to reflash phone?