HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

[Swell61]

Hiya

I found a faulty HP Pavillion 14-ce3514sa am having a stab at repairing it.

Motherboard is G7AL-2G DAG7ALMB8C0 REV: C

The board doesn't boot when the power button is pressed. The charger LED comes on when it is plugged in and when the power button is pressed, the main voltages are present on the board, the fan spins and the power LED comes on, but there's nothing on the screen (neither the built in one nor the HDMI out) and the keyboard doesn't light up.

The first and possibly only thing concerning now is VCCIN for the CPU. After the board has been powered on for 30-60 seconds, the CPU heats up quite a lot, and the two output regulators(? not sure that's what they are) get *very* hot, to the point where I can't touch them for more than a second or two. I measured 1.8V at the power supply output for the CPU and (I'm not sure this is relevant) I measure around 80ohms from VCCIN to ground. I had a dig through Intel's datasheet for 10th gen CPUs, and, if I'm understanding it correctly, the voltage should not exceed 1.52V.

Where I've measured is the output of the two things in green boxes at the top in this photo from another post about this motherboard on this forum (the bottom green box for the DRAM measures the correct 1.2V).

Does this mean that the CPU has been waaaaay overvolted and is now toast? I've found one other case of this motherboard with this issue online but the poster didn't update with what the problem ended up being.

Edit: Attached screenshot from the datasheet. It's from Intel doc number: 615211-008

[piernov]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

Incorrect datasheet. Core i5-1035G1 is from Ice Lake family and that has FIVR.

[mcplslg123]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

1.8V at Vcore is correct for 10th/11th gen cpu.Absolutely sure.

[Swell61]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

Ah, well that's good news! Thank you both

I shall continue diagnostics later. I've only got as far as checking the main voltages so far. Are they any "check this first" tips you can give for this sort of motherboard? I'll be trying to follow through with the schematics.

I appreciate the help

Edit: Oh and does the 80ohms mean anything?

[mcplslg123]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

80 Ohms is fine. Check whether DRAMRST# is present on pin108 of ram slot.Make a backup of your existing bios and flash known good clean me bios.

[mcplslg123]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

Another thing i recommend is to replace the vcore coils with marking R15 or R22. Measure voltage on vcore rail again and very likely you'll get 1.5-1.6V instead of 1.8V and system will be relatively cooler. Wierd but works on 10th gen onwards.

[Swell61]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

Thanks

New BIOS didn't seem to change anything.

For DRAMRST, when I power on the board, it goes to about 100mV for around 8 seconds, and then it goes up to 1.2V.

[mcplslg123]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

DRAMRST# is fine too.

[Swell61]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

Ok. Is there anything else you think I should check? I put a logic analyser on the BIOS flash chip and there's some activity when the board is powered on, though I can't tell what it is doing because the logic analyzer sample frequency isn't high enough.

[mcplslg123]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

Have you replaced the coils i suggested?

[Swell61]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

Ah, no, I thought that was something I could do after I confirmed it was working, I didn't realise it was part of troubleshooting. I shall order some replacement coils

[Swell61]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

I haven't managed to find any of the correct specification in small quantities without insane shipping prices yet. Would it be possible to continue troubleshooting without swapping them and then swap them once it is known working?

[Swell61]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

Update: I found some gunk (looks like a sticker) in the RAM slot on one end that looked like it was preventing proper contact with the DIMM (it could have been shorting the pins, I didn't check before I cleaned it). I've cleaned it all out and now the RAM and CPU voltages have gone when I power it on, they're both 0. I can hear coil whine when I turn it on now. It seems that my symptoms now match those from the thread I used the picture from - https://www.badcaps.net/forum/showthread.php?p=1233066

Update on the update: Old behaviour is back, voltages are back and the CPU and coils are getting hot

[Swell61]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

It's something to do with the RAM slot. I just pressed a lot of weight on it with my hand and powered it on, and I got a screen about the CMOS battery being disconnected out of the HDMI port

[reformatt]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

Check for loose pins at each end of the DIMM slot. Usually its on the inner row that pins are loose and need resoldering. I just use the nose of my tweezers to nudge each pin to see if they move. Seen this on a few models now.

[mcplslg123]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

Check for loose pins at each end of the DIMM slot. Usually its on the inner row that pins are loose and need resoldering. I just use the nose of my tweezers to nudge each pin to see if they move. Seen this on a few models now.

Very common with newer HP'S specially.

[Swell61]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

I've resoldered all of the pins on the DIMM slot. The board booted a couple of times but it had the intermittent no RAM or VCCIN voltage problem. Now it has that problem consistently and doesn't boot at all. Something isn't turning on those power rails

[Swell61]

Re: HP Pavilion 14-ce3514sa G7AL-2G DAG7ALMB8C0 REV: C diagnostics

Following the request on the other thread, I've measure the pins on PU4 (schematic) / PU8300 (boardview) / PU12 (other thread) - the RT8231BGQW for the RAM:
Pin 4 (VTTREF): 0V
Pin 7 (1P35V_S3/MAINON): 0V
Pin 8 (1P35V_S5): 0V
Pin 9 (1P35VTON): 18.9V
Pin 11 (1P35_VID): 5.1V
Pin 12 (+5VS5): 5.1V

I'm not sure where to measure VCCSA/PCHPOWER. PCH_PWROK is 0V and VCCIN_AUX (not on the schematic but is in boardview) is also 0V. RSMRST is 3.3V.