Acer Aspire 3820TG - completely dead

[DeniS182]

Hi,
I need help with this notebook. Notebook is completely dead. No lights, no beeps, nothing. I measured some voltages on motherboard. 3.3V and 5V aux voltages are ok. I measured 0V on U27 - RT8223BGQW-GP pin 18 (S5_enable). I don't know what next I should measure. Can you help me?

Thanks for answer.

Motherboard: JM31-CP
Revision: 09921-3

Schematic: https://dl.dropboxusercontent.com/u/...5-1047_144.pdf

[dj_ricoh]

Re: Acer Aspire 3820TG - completely dead

hy there!

so lets focus on page 47 charging IC . U36

post the voltages from that ISL

[polytek]

Re: Acer Aspire 3820TG - completely dead

try to flash the bios:

[DeniS182]

Re: Acer Aspire 3820TG - completely dead

Hi,
thanks for answer. The are voltages:
U36 - ISL88731AHRZ-T-GP
1 - NC
2 - 3.55 V
3 - 3.21 V
4 - 0 V
5 - 0 V
6 - 0 V
7 - NC
8 - 0 V
9 - 3.34 V
10 - 3.34 V
11 - 0 V
12 - gnd
13 - 3.04 V
14 - NC
15 - 2.5 V
16 - nc
17 - 2.77 V
18 - 2.7 V
19 - pgnd
20 - 0
21 - 5.08 V
22 - 19.2 V
23 - 2 V
24 - 2.88 V
25 - 4.8 V
26 - 5.08 V
27 - 19.36 V
28 - 19.36 V

Voltages on some pins may be little inaccurate because value on voltmeter wasn't stable.

How can I flash bios? Rom is W25Q32BVSSIG-1-GP
Anybody out there know some easy to build programmer?

[dj_ricoh]

Re: Acer Aspire 3820TG - completely dead

fix your DMM or confirm that PIN 2 got that voltage.
pin2- 3.55 V (good its 19v)

[Blacktek]

Re: Acer Aspire 3820TG - completely dead

might be the resistor R350, pin 22 is getting the right voltage

[dj_ricoh]

Re: Acer Aspire 3820TG - completely dead

might be the resistor R350, pin 22 is getting the right voltage

yep!
your right.

but in this case when ACIN is high(3.5v) ACOK must be low?

Connect the AC-adapter voltage through a resistor divider to ACIN
to detect when AC power is available, as shown in Figure 2. ACOK
is an open-drain output and is active low when ACIN is less than
Vth,fall, and high when ACIN is above Vth,rise. The ACIN rising
threshold is 3.2V (typ) with 57mV hysteresis

[dj_ricoh]

Re: Acer Aspire 3820TG - completely dead

i confuse the acin with dcin.
but in this case acin with acok its in question.

[dj_ricoh]

Re: Acer Aspire 3820TG - completely dead

those values or with battery or without?

[DeniS182]

Re: Acer Aspire 3820TG - completely dead

I measured it again with other DMM. New values:
1 - NC
2 - 3.56 V
3 - 3.21 V
4 - 0 V
5 - 0 V
6 - 0 V
7 - NC
8 - 0 V
9 - 3.35 V
10 - 3.35V
11 - 0 V
12 - gnd
13 - 3.05V
14 - NC
15 - 2.50V *
16 - nc
17 - 2 v *
18 - 2v *
19 - pgnd
20 - 0 v
21 - 5.09v
22 - 19.23 v
23 - 2.5v *
24 - 2.4v *
25 - 4.8 v
26 - 5.08v
27 - 19.39v
28 - 19.39v

Only values marked with * are unstable. Voltage on these pins drop 1 mV per second on dmm.

And those values are measured without battery.

[meritosari]

Re: Acer Aspire 3820TG - completely dead

voltage u27 pin#12 and pin#19?

[dj_ricoh]

Re: Acer Aspire 3820TG - completely dead

i think there is a short either on 3.3v or 5v rail.

check the coils and see if you got short on l40 or l45

[Blacktek]

Re: Acer Aspire 3820TG - completely dead

check FET's u25,u23,u15 and u18 while you at it

[DeniS182]

Re: Acer Aspire 3820TG - completely dead

U27 - PIN19 and PIN12 = 0V
L40 and L45 without short circuit.

[DeniS182]

Re: Acer Aspire 3820TG - completely dead

u26,u25,u23,u15,u18 without short circuit. I mean they are ok. I test it also with component tester but because of I measured it without desolder all mosfets detect as 2*diode. How you test mosfets which are soldered on pcb?

[Blacktek]

Re: Acer Aspire 3820TG - completely dead

how about pin 16 on u27, what voltage are u getting? i check mosfet by setting my testes to continuity. there should be no continuity on any pins while the fet is onboard, if you desolder it, it should beep.

[DeniS182]

Re: Acer Aspire 3820TG - completely dead

U27 - 16pin - 19.4V
And I too measure it like you and with ohmmeter.

[meritosari]

Re: Acer Aspire 3820TG - completely dead

try measure voltage on pin 1,3,6,13 and 18. then measure again on pin 12 and 19 ( its look to "force" enable the IC) if one of pin 12 and 19 got high (4.05v). then its OVP (output over voltage).

don't forget measure resistance respect to ground on pin 23

[DeniS182]

Re: Acer Aspire 3820TG - completely dead

Pin 1 - 0V
Pin 3 - 2.0V
Pin 6 - 0V
Pin 13 - 6.1V
Pin 18 - 0V
Pin 12 - 0V
Pin 19 - 0V
Pin 23 resistance to ground - 235KΩ

[DeniS182]

Re: Acer Aspire 3820TG - completely dead

I want try flash bios. I have USB asp programmer v2.0 with 3.3V regulator and software PROGISP(Ver1.71) and in this soft in "select chip" I found W25x32 and MX25L1005 too. Can you help me how to connect this programmer to these rom's? Some schematic please?
Thank's all for answers in this theme!