HP tpn-q139 startup 0.00-0.01-0.00 auto power off troubleshooting

First measure Switch, with 3.3V, and then measure rsmrst ා. It is found that VCC is also normal, which indicates that VCC is also normal;R256 back end, found that VCC difference is a little big, too low, found a 10k to replace, only 1.69v.Press Switch again, the current is normal.

[machine model] HP tpn-q139
[fault phenomenon] startup 0.00-0.01-0.00 auto power off
[maintenance process]

Drawing: quanta day11amb6e0
Point: no point, refer to q172 point
Colleagues sent it, the computer was originally good, after a few days of business trip,no power on, the computer can not be opened.After getting the computer, I found that it was also repaired by someone, including BIOS, memory VCC and level 2 convert transistor.

HP tpn-q139 startup 0.00-0.01-0.00 auto power off maintenance experience Figure 1

HP tpn-q139 startup 0.00-0.01-0.00 auto power off maintenance experience Figure 2
The iron label on the C shell, this machine;

HP tpn-q139 startup 0.00-0.01-0.00 auto power off maintenance experience Figure 3
The model behind the d-case battery can’t be seen without paying attention. At that time, I asked my colleague that he had been looking for it for a long time, but he couldn’t find out where the model was.

HP tpn-q139 startup 0.00-0.01-0.00 auto power off maintenance experience Figure 4
The maintenance road starts, plug in the power adapter, standby 000,

HP tpn-q139 startup 0.00-0.01-0.00 auto power off maintenance experience Figure 5
DC power supply press Switch.01, you can see if there is any reaction,
current change indicates that EC should be working, and then measure rsmrst ා. It is found that VCC is also normal, which indicates that VCC is also normal.

HP tpn-q139 startup 0.00-0.01-0.00 auto power off maintenance experience Figure 6

HP tpn-q139 startup 0.00-0.01-0.00 auto power off maintenance experience Figure 7
This is rsmrst ා compared with SLP. If the demerit is found to be SLP, it will be dropped first, indicating that the bridge condition is not satisfied.

HP tpn-q139 startup 0.00-0.01-0.00 auto power off maintenance experience figure 8

HP tpn-q139 startup 0.00-0.01-0.00 auto power off maintenance experience Figure 9
Bridge RTC circuit r277 resistance front section,

HP tpn-q139 startup 0.00-0.01-0.00 auto power off maintenance experience Figure 10

I found a 10k one and replaced it with 1.69v Figure 11
At the back end of r256, it was found that the difference of VCC was a little big, too low. Clamp 256 ends with tweezers, press Switch, and the current will brush up. Find a 20K resistor to replace it, or only 0.9V. If you find a 10k one, it will be 1.69v.