Hp Elitebook 8470p is restart with ram and touch

[usyusy]

Hi to all
Hp Elitebook 8470p restart with ram installed, or if I touch on the step down 3v/5v section (pic attached)
However if I remove ram or any ram, it continue to carry on.
Readings on charger IC (U6000 on page 4 of attached schematic) are as folows: when laptop off and charger connected only;

1... ACN...... 19.85v
2... ACP..... 19.85
3... CMSRC..... 19.75
4... ACDRV..... (1)
5... ACPRESS ..... 3.25
6... ACDET..... 2.67
7... IOUT..... 0
8... SDA.... 3.30
9... SCL..... 3.30
10... ILIM..... 3.19
11... DLIM..... 0
12... SRN..... 1.78
13... SRP...... 1.79
14... GND..... 0
15... LODRV..... 0
16... REGN...... 6.13
17... BTST..... 5.93
18... HIDRV..... 1.79
19... PHASE..... 1.79
20... VCC...... 19.23

While the readings on 3v/5v step down ic are as under : when laptop off with charger attached;

1...TRIP1..... 0
2...VFB1..... 0
3...VREF..... 2.01
4...TONSEL..... 3.33
5...VFB2..... 0
6...TRIP2.....0
7...VO2.....0
8...VREG3..... 3.32
9...VBST2.....4.50
10...DRVH2..... 0
11...LL2..... 0
12...DRVL2..... 0
13...EN0..... 1.69
14...SKIPSEL..... 0
15...GND.....0
16...VIN..... 19.0
17...VREG5..... 5.02
18...ENC..... 0
19...DRVL1..... 0
20...LL1..... 0
21...DRVH1..... 0
22...VBST1..... 0.. 0
23...PGOOD.....0
24...VO1..... 0

[mon2]

Re: Hp Elitebook 8470p is restart with ram and touch

Is the ram confirmed to be 100% compatible with this box ?

Sounds like you have defective ram unless proven otherwise.

[usyusy]

Re: Hp Elitebook 8470p is restart with ram and touch

Is the ram confirmed to be 100% compatible with this box ?

Sounds like you have defective ram unless proven otherwise.

Dear sir, thanks
I changed ram with working one from hp elitebook 2570p, even test others, same result

[mcplslg123]

Re: Hp Elitebook 8470p is restart with ram and touch

Very likely to be bios issue. When you are removing ram, a lot of S0 rails are not coming up and perhaps thats why it remains on. Try flashing bios first with an external spi programmer.