la-9104p MB 7 Beeps error and no display

[lapfix]

Re: la-9104p MB 7 Beeps error and no display

Techtiger , maybe the solution is to to dump the 9012chip !

take a look : https://www.youtube.com/watch?v=mgNwI4CrnL4

[Techtiger]

Re: la-9104p MB 7 Beeps error and no display

Interesting do you have the crystal checker if not change the YH2

[mcplslg123]

Re: la-9104p MB 7 Beeps error and no display

For DRAMRST# , i think it must be active low ! i find 0.049v at pin 30 of ram slot.

Any other place to check !!

It has to be 1.35V. Dramrst#-dont get confused. Just compare Lidsw#. Is that not 3.3V to work.?? Check PG signals of each and every Ic as this mb is typical where PG of one ic becomes EN of another IC. Look at schematic carefully

[lapfix]

Re: la-9104p MB 7 Beeps error and no display

Hello folks
Techtiger : i change it before but stil same issue

mcplslg : yes ou are right and this is the new reading with compare it ones from a good board .

UC3 :

Pin 2 = PLT_RST# = 0V ( 3.41V on goodboard )
Pin 4 = BUFO_CPU_RST# = 0.74V ( 1.073V On goodboard )
Pin 5 = VCC = +3VALW ( OK)

UH3 :

Pin 1 = IN1 = 3.36V ( Ok)
pin 2 = IN2 = 0.011V ( 3.42V goodboard )
Pin 4 = SYS_PWROK = 0.005V ( 3.42V goodboard)
Pin 5 = VCC = 3.42V ( Ok)

UC2 :

Pin 1 = 3.38 ( ok)
Pin 2 = DRAM_PWRGD = 0.532V ( 3.39V goodboard )
Pin 4 = VDDPWRGOOD = 0.25V ( 1.5V goodboard )
Pin 5 = VCC = 3.40V ( Ok)

Pin 30 = DDR3_DRAMRST# = 0.049v ( 1.5V goodboard)

Lid-sw = 3.40V

So ,many voltages didn't exist ..try to find why...if you have any other suggestion or demand , please ask it

[mcplslg123]

Re: la-9104p MB 7 Beeps error and no display

Check QZ3/4/8/10. Pl400 Voltage present??PU500 Pin1 Voltage?? PR501 voltage on both sides??

[lapfix]

Re: la-9104p MB 7 Beeps error and no display

QZ3 is ok :
D = 3.41v
G =14.69v
S = 3.39v

PU 400 = 1.825v

PR 501 = 3.40v---3.07v
PU 500 = pin 1 = 3.07v

[mcplslg123]

Re: la-9104p MB 7 Beeps error and no display

QZ3 is ok :
D = 3.41v
G =14.69v
S = 3.39v

PU 400 = 1.825v

PR 501 = 3.40v---3.07v
PU 500 = pin 1 = 3.07v

All is fine here. Is there any missing Rails??

[mcplslg123]

Re: la-9104p MB 7 Beeps error and no display

Cpu is getting +1.35V Supply?? This is a must for Dramrst#

[mcplslg123]

Re: la-9104p MB 7 Beeps error and no display

Voltage present on PL600??

[lapfix]

Re: la-9104p MB 7 Beeps error and no display

I will take measurements after.
have another one , comes today ..same issue of 7beeps..PL500 =0v....PR501 = 3.3v from 1side/ 0v from the PU500. ( 91KOHM)...i change it and still not got the Voltage !

On this second board , the ampere start from 0.240 and increase with fan speed too

[lapfix]

Re: la-9104p MB 7 Beeps error and no display

This is the measurements For PU500 From working Motherboard, maybe it help other for diagnostic.

PU 500 :

PL500 = 1.078v

Pin1 = 3.70v
Pin2 = 0.540v
Pin3 = 3.200v
Pin4 = 0.719v
Pin5 = 0v
Pin6 = 4.68v
Pin7 = 5.00v
Pin8 = 1.056v
Pin9 = 1.314v
Pin10 = 5.60v

[mcplslg123]

Re: la-9104p MB 7 Beeps error and no display

I will take measurements after.
have another one , comes today ..same issue of 7beeps..PL500 =0v....PR501 = 3.3v from 1side/ 0v from the PU500. ( 91KOHM)...i change it and still not got the Voltage !

On this second board , the ampere start from 0.240 and increase with fan speed too

That means you dont have +V1.05S_VCCP_PWRGOOD signal. This is PG for PU500 and EN for PU600 to generate VCCSAP. If PR501 is ok, either PU500 or PU600 is likely to be bad. Try replacing them.

[lapfix]

Re: la-9104p MB 7 Beeps error and no display

That's crazy !!
For the first one , power on :
PL 500 = 1.056v
PL 600 = 0.950v
PL 701 = 1.137v !!!
7 beeps still and current consumption = 0.240amp

Power off , try again , no volt on PL 701 with 7 beeps too , current consumption 0.140Amp

PL 500 = 1.056v
PL 600 = 0.950v
PL 701 = 0v

[mcplslg123]

Re: la-9104p MB 7 Beeps error and no display

Thats really crazy but still check pin27 of PU700 for IMVP_PWRGD. Btw, you flashed both main & EC bios?? Cmos battery is not below 3V??

[lapfix]

Re: la-9104p MB 7 Beeps error and no display

Hello again
Yes strange thing , yes i flashed UH6/UH2 with a know dump.
Cmos bat = 3.07v
pu700
pin 27 = 0v
pin 21/22 = 5vs
pin 2 =3.39
pin13=3.38

[Spider1211]

Re: la-9104p MB 7 Beeps error and no display

Hello, do you have activity on both BIOS? Check pin 1 with an oscilloscope (measure while turning laptop ON). I have a similar issue (7 beeps) with a LA-9101P but no activity on BIOS.

Everything else seem to check out, am starting to lean towards a bad PCH at this point.

[lapfix]

Re: la-9104p MB 7 Beeps error and no display

Hello spider and thank you
unfortunately i don 't have oscilloscope..maybe a PCH but try to confirm ...
i solve another customer 3521 same issue..that's why i still believe tha's not a PCH r a CPU issue.
BTW , i change PU700 same beep

[Spider1211]

Re: la-9104p MB 7 Beeps error and no display

It's quite rare that it is an actual CPU issue. I did have a PCH issue in the past but ofcourse the PCH is the last I would blame.

i solve another customer 3521 same issue

Which part/IC was the problem?

[mcplslg123]

Re: la-9104p MB 7 Beeps error and no display

I've faced actual cpu failure on dell 3521 but only once and replacing the cpu did solved the problem. Most of the time if cpu fails, caps in ram area will show low rating . So @lapfix, do compare rating of caps in ram area between good board and defective one.

[Spider1211]

Re: la-9104p MB 7 Beeps error and no display

I may have spoken too early as I might have a bad CPU afterall. I went back and rechecked the LA-9101P and how would you know...+VCC_GFXCORE_AXG is missing (no idea how I missed that). PU700 is ok and +VCC_Core is also present.

With PU700 off the board (although It should not matter) I have a short on VSS_AXG_SENSE and VCC_AXG_SENSE. These 2 signal go directly to the CPU. I already checked any components on those line and they seem OK.

My readings (resistance to ground):
>PL700 - 1.68ohms (I was expecting this to be low, but that low?)
>FBG - 2.601KOhms
>RTNG - 0.21Ohms
>+VCC_GFXCORE_AXG and FBG - 2.601KOhms

>IMVP_PWRGD (pin 85 of KB9012) is jumping all over the place and is 0V on PU700 side.

Per schematic, I would have expected VSS_AXG_SENSE (RTNG to ground) to be around 100 Ohms and VCC_AXG_SENSE (+VCC_GFXCORE_AXG to FBG) to be around 2.701 KOhms.


@Lapfix, can you please share reading of PU700(resistance to ground) from your known good board for the following:

- PL700
- FBG (pin 29)
- RTNG (pin 30)
- Resistance between +VCC_GFXCORE_AXG and FBG(pin 29)

- IMVP_PWRGD voltage on pin85 of KB9012 and on pin 27 of PU700