strange T20s display - GSM-Forum

trafix · 04-01-2002, 19:10

have this T20s that when i power on the phone the display is ok for about 2 secs and then gradually DARKENS... that 3 secs more and the screen is completely dark! No idea if this is a software or hw related

any suggestions are most welcome...

Lead · 04-06-2002, 08:44

This happens when one changes the display type (also in eeprom), but does not change its calibration values. These values are specific for each display type.

Lead · 04-06-2002, 08:54

Try writing one of the following sequences to the eeprom address 0A85 (make backup first):

00 03 01 00 28 58 02 35 02 49 02 35 41 25 03 01
00 28 49 02 5D 02 26 02 2F 56 21

00 03 01 00 28 4E 02 3F 02 3A 02 2F 32 28 03 01
00 28 4E 02 67 02 21 02 2F 46 21

02 03 01 00 28 58 02 35 02 49 02 2F 41 25 03 01
00 28 4E 02 67 02 2B 02 36 56 21

I really don't know which one will work for you...

trafix · 04-06-2002, 19:05

thanks lead, I'll try this solution as soon as i can and post the results

trafix · 04-10-2002, 23:45

@LEAD: unfortunately the solution did not work.. tried the 3 modifications.. how about flashing the flash? what sw can i use for safely flashing t20?

or maybe upgrading to t29? I'd like to use sw solution first before opening the phone... Thanks for the time man!

Any other suggestions is very much appreciated

Lead · 04-11-2002, 00:33

If none of the sequences worked, then it is probably a hardware problem and therefore it cannot be solved by flashing.
We may try calibrating voltages, so, at least, tell me which of these three sequences worked for you best.

trafix · 04-11-2002, 02:00

ok thanks, I'll try hw solution when i get hold of an LCD

all the 3 modifications are the same man, the problem persists, when i turn ON the phone it shows display in a split second the slowly darkens and in about 5 secs it is totally dark... strange huh?

Lead · 04-11-2002, 04:39

The last one has the same result as previous two sequences?

trafix · 04-11-2002, 05:45

yup, hasn't changed at all, phone still darkens the display and after 5 secs totally dark, haven't tried changing LCD yet cuz' I ain't got any

best regards!

ARS · 04-16-2002, 03:45

I have a similar problem with T20. I have repaired a charging problem, phone works OK. I give it back to owner. On next dey he comm back with this problem....LCD is dark. Phone normal power on and LCD is dark, i can see what is on display, but is it dark. I have tryed changing LCD, dont work, contrast settings dont works too. No one have played with firmware or eeprom, but i will try to make settings as Leads wrote. Any other ideas are welcome

microera · 08-03-2002, 19:29

I have similar problem...
See:
http://forum.gsmhosting.com/vbb/show...threadid=51842

best regards,

loopkiller · 09-04-2002, 15:11

boys try to change ad/da convertor,it is part between flash and clock

fofodaman · 09-09-2002, 18:22

guys. what S/W are you using to read/write eeprom ?
& where can it be found?

gibso · 05-06-2003, 16:37

guys i have a t20 with good lcd but no display,
but when you take a very close look you will notice a very very faint display.
someone pls help.

thank,

gibso

L_DIM2003 · 05-13-2003, 07:32

hello all.
try to disconnect VLCD contact from phone supplier to other supplier about 4.8 V. if LCD wil work than hw problem i think.

sorry my english

04-01-2002, 19:10	#1 (permalink)
trafix No Life Poster Join Date: Jun 2001 Location: Philippines Age: 47 Posts: 942 Member: 4873 Status: Offline Thanks Meter: 5	strange T20s display have this T20s that when i power on the phone the display is ok for about 2 secs and then gradually DARKENS... that 3 secs more and the screen is completely dark! No idea if this is a software or hw related any suggestions are most welcome...

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04-06-2002, 08:44	#2 (permalink)
Lead No Life Poster Join Date: Aug 2008 Age: 52 Posts: 3,292 Member: 1841 Status: Offline Thanks Meter: 469	This happens when one changes the display type (also in eeprom), but does not change its calibration values. These values are specific for each display type.

04-06-2002, 08:54	#3 (permalink)
Lead No Life Poster Join Date: Aug 2008 Age: 52 Posts: 3,292 Member: 1841 Status: Offline Thanks Meter: 469	Try writing one of the following sequences to the eeprom address 0A85 (make backup first): 00 03 01 00 28 58 02 35 02 49 02 35 41 25 03 01 00 28 49 02 5D 02 26 02 2F 56 21 00 03 01 00 28 4E 02 3F 02 3A 02 2F 32 28 03 01 00 28 4E 02 67 02 21 02 2F 46 21 02 03 01 00 28 58 02 35 02 49 02 2F 41 25 03 01 00 28 4E 02 67 02 2B 02 36 56 21 I really don't know which one will work for you...

04-06-2002, 19:05	#4 (permalink)
trafix No Life Poster Join Date: Jun 2001 Location: Philippines Age: 47 Posts: 942 Member: 4873 Status: Offline Thanks Meter: 5	thanks lead, I'll try this solution as soon as i can and post the results

04-10-2002, 23:45	#5 (permalink)
trafix No Life Poster Join Date: Jun 2001 Location: Philippines Age: 47 Posts: 942 Member: 4873 Status: Offline Thanks Meter: 5	@LEAD: unfortunately the solution did not work.. tried the 3 modifications.. how about flashing the flash? what sw can i use for safely flashing t20? or maybe upgrading to t29? I'd like to use sw solution first before opening the phone... Thanks for the time man! Any other suggestions is very much appreciated

04-11-2002, 00:33	#6 (permalink)
Lead No Life Poster Join Date: Aug 2008 Age: 52 Posts: 3,292 Member: 1841 Status: Offline Thanks Meter: 469	If none of the sequences worked, then it is probably a hardware problem and therefore it cannot be solved by flashing. We may try calibrating voltages, so, at least, tell me which of these three sequences worked for you best.

04-11-2002, 02:00	#7 (permalink)
trafix No Life Poster Join Date: Jun 2001 Location: Philippines Age: 47 Posts: 942 Member: 4873 Status: Offline Thanks Meter: 5	ok thanks, I'll try hw solution when i get hold of an LCD all the 3 modifications are the same man, the problem persists, when i turn ON the phone it shows display in a split second the slowly darkens and in about 5 secs it is totally dark... strange huh?

04-11-2002, 04:39	#8 (permalink)
Lead No Life Poster Join Date: Aug 2008 Age: 52 Posts: 3,292 Member: 1841 Status: Offline Thanks Meter: 469	The last one has the same result as previous two sequences?

04-11-2002, 05:45	#9 (permalink)
trafix No Life Poster Join Date: Jun 2001 Location: Philippines Age: 47 Posts: 942 Member: 4873 Status: Offline Thanks Meter: 5	yup, hasn't changed at all, phone still darkens the display and after 5 secs totally dark, haven't tried changing LCD yet cuz' I ain't got any best regards!

04-16-2002, 03:45	#10 (permalink)
ARS No Life Poster Join Date: Dec 2000 Location: Slovakia, Brezno Posts: 980 Member: 2721 Status: Offline Thanks Meter: 23	I have a similar problem with T20. I have repaired a charging problem, phone works OK. I give it back to owner. On next dey he comm back with this problem....LCD is dark. Phone normal power on and LCD is dark, i can see what is on display, but is it dark. I have tryed changing LCD, dont work, contrast settings dont works too. No one have played with firmware or eeprom, but i will try to make settings as Leads wrote. Any other ideas are welcome

08-03-2002, 19:29	#11 (permalink)
microera No Life Poster Join Date: Jun 2001 Location: www.microera.si Posts: 1,535 Member: 4923 Status: Offline Thanks Meter: 74	I have similar problem... See: http://forum.gsmhosting.com/vbb/show...threadid=51842 best regards,

09-04-2002, 15:11	#12 (permalink)
loopkiller Freak Poster Join Date: Oct 2001 Age: 41 Posts: 258 Member: 7072 Status: Offline Thanks Meter: 10	boys try to change ad/da convertor,it is part between flash and clock

09-09-2002, 18:22	#13 (permalink)
fofodaman Freak Poster Join Date: Jan 2002 Location: Leon Posts: 461 Member: 8804 Status: Offline Thanks Meter: 4	guys. what S/W are you using to read/write eeprom ? & where can it be found?

05-06-2003, 16:37	#14 (permalink)
gibso No Life Poster Join Date: Mar 2003 Location: Port Harcourt, River State, Nigeria Age: 45 Posts: 541 Member: 25150 Status: Offline Thanks Meter: 8	guys i have a t20 with good lcd but no display, but when you take a very close look you will notice a very very faint display. someone pls help. thank, gibso

05-13-2003, 07:32	#15 (permalink)
L_DIM2003 Freak Poster Join Date: May 2003 Posts: 117 Member: 27990 Status: Offline Thanks Meter: 0	hello all. try to disconnect VLCD contact from phone supplier to other supplier about 4.8 V. if LCD wil work than hw problem i think. sorry my english