Acer Aspire 5551 no power
As this is my first Thread I would like to welcome everyone and apologize for my English.
I have my testing laptop Acer Aspire 5551 with motherboard NEW55 LA-5912P Rev: 1.0.
Short story of this laptop. Laptop worked fine till I wanted add some ram and did not want to power up. After diagnosing I reprogrammed bios and found out that PQ31 had strange measurement outcome so I replaced and luckily laptop came back to life. There were still defects like there was no battery charging, U70 got very hot and laptop turned off after a while.
To make things worse, by mistake I made short in the charger PU5. Now laptop does not give any sign of life.
I made measurements on the B+ rail.
Given voltage from power supply: VIN 19V
Current uptake in ST-BY: 0V
No volt. on main coils 3V\5V PL3 \ PL4.
Resistance to ground: PL4( 50 i 30 KΩ i PL3 (1.6Ω)
PL1- 19V
PU1 (LM393):
leg.1 – (PACIN) 1OUT, 3.13V
leg.2—RTCVREF, IN-, 3.28V
leg.3—VIN, IN+, 3.60V
leg.4 - gnd
leg.8- VS vcc, 18.30V
PD1 Zener diode: K 3.13v, A 0V
PD2: K 18.35V A 18.98V
PQ1 : (TP0610K): D 18.32 V, S 17.80V, G 17.63V
PU2: (GT920 T24):
Vin 17.80V
Vout 3.28V
PU3:
Vcc 0V , rez 53KΩ
PQ3: Dren Line B+ 0V ,PR34 0V
I will be very grateful for any suggestions on where to make measurement and what value I should expect to locate the culprit.
I have my testing laptop Acer Aspire 5551 with motherboard NEW55 LA-5912P Rev: 1.0.
Short story of this laptop. Laptop worked fine till I wanted add some ram and did not want to power up. After diagnosing I reprogrammed bios and found out that PQ31 had strange measurement outcome so I replaced and luckily laptop came back to life. There were still defects like there was no battery charging, U70 got very hot and laptop turned off after a while.
To make things worse, by mistake I made short in the charger PU5. Now laptop does not give any sign of life.
I made measurements on the B+ rail.
Given voltage from power supply: VIN 19V
Current uptake in ST-BY: 0V
No volt. on main coils 3V\5V PL3 \ PL4.
Resistance to ground: PL4( 50 i 30 KΩ i PL3 (1.6Ω)
PL1- 19V
PU1 (LM393):
leg.1 – (PACIN) 1OUT, 3.13V
leg.2—RTCVREF, IN-, 3.28V
leg.3—VIN, IN+, 3.60V
leg.4 - gnd
leg.8- VS vcc, 18.30V
PD1 Zener diode: K 3.13v, A 0V
PD2: K 18.35V A 18.98V
PQ1 : (TP0610K): D 18.32 V, S 17.80V, G 17.63V
PU2: (GT920 T24):
Vin 17.80V
Vout 3.28V
PU3:
Vcc 0V , rez 53KΩ
PQ3: Dren Line B+ 0V ,PR34 0V
I will be very grateful for any suggestions on where to make measurement and what value I should expect to locate the culprit.
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