Dell Inspiron 15 3537 Compal LA-9982P

[ziko07]

Hi , I have this laptop with no picture problem, also mo picture on external monitor via hdmi port.
All coil voltage present, IC for LVDS has all voltages.
Any tips?

Thanks

[Techtiger]

Re: Dell Inspiron 15 3537 Compal LA-9982P

What voltage are present with coil reference? Have you Test with a work RAM ? is the DRAMRST Signal present on ram slot pin 30 ?

[ziko07]

Re: Dell Inspiron 15 3537 Compal LA-9982P

Yes tested with working RAM voltage on ram ok,also that half ram voltage ok,DRAMRST should be what voltage,ir need to test with oscilloscope?
Tnx

P.S No any voltage on that pin

[Sametbey]

Re: Dell Inspiron 15 3537 Compal LA-9982P

The operating voltages of the RAM socket were measured on the Dell 5521 model. might help.

[Techtiger]

Re: Dell Inspiron 15 3537 Compal LA-9982P

Sametbey good JOB

[ziko07]

Re: Dell Inspiron 15 3537 Compal LA-9982P

Thanks, I also found on net samething about pin 30

[ziko07]

Re: Dell Inspiron 15 3537 Compal LA-9982P

I did some measurment, DRAMRST# is missing
DDR_PG_CTRL 1.35v
0.675V_DDR_VTT_ON 4.88v, is this normaL? because I see 0.675v named net but voltage diveder looks ok
Here images for measurment
To have DRAMRST# voltage I guess need to be present some other signal,but not know which one. DRAMRST# goes from CPU

[Techtiger]

Re: Dell Inspiron 15 3537 Compal LA-9982P

I did some measurment, DRAMRST# is missing
DDR_PG_CTRL 1.35v
0.675V_DDR_VTT_ON 4.88v, is this normaL? because I see 0.675v named net but voltage diveder looks ok
Here images for measurment
To have DRAMRST# voltage I guess need to be present some other signal,but not know which one. DRAMRST# goes from CPU

check the Ram slot pin 203 voltage if its +0675VS the move on, for 0.675V_DDR_VTT_ON 4.88v this is ok since @R2351 is not in used so V-Divider

check RD3 470 with out power resistance, what is the voltage on J510 J511 VS

[mcplslg123]

Re: Dell Inspiron 15 3537 Compal LA-9982P

Just bringing it to notice-This mb wont post unless edp cable with screen is plugged in.

[ziko07]

Re: Dell Inspiron 15 3537 Compal LA-9982P

RD3 is ok,j510,j511 voltage present pin203 ram ok. All ram voltages ok except dramrst#. I saw other boards ,before dramrst# must have ok signal dram_pwrok,but not have on this board so named signal,maybe other named so if you have sch please find it.PLT_RST also present 3v2


Tnx

[Techtiger]

Re: Dell Inspiron 15 3537 Compal LA-9982P

Just bringing it to notice-This mb wont post unless edp cable with screen is plugged in.

is the Edp câble plugged in as mcplslg123! Mentions?

[ziko07]

Re: Dell Inspiron 15 3537 Compal LA-9982P

No, just hdmi,but servicer bring no picture laotop problem.if not lcd connected will affect dramrst#?

[Techtiger]

Re: Dell Inspiron 15 3537 Compal LA-9982P

RD3 is ok,j510,j511 voltage present pin203 ram ok. All ram voltages ok except dramrst#. I saw other boards ,before dramrst# must have ok signal dram_pwrok,but not have on this board so named signal,maybe other named so if you have sch please find it.PLT_RST also present 3v2


Tnx

You have not given the readings RD3 j510,j511 pin203

[Techtiger]

Re: Dell Inspiron 15 3537 Compal LA-9982P

No, just hdmi,but servicer bring no picture laotop problem.if not lcd connected will affect dramrst#?

Nop what is the voltage U2303 all pin

[ziko07]

Re: Dell Inspiron 15 3537 Compal LA-9982P

I put measurements of u2303 above in attachment
Post #6

Pin2 = 1.36v
Pin5 = 1 35v
Pin4 = 4.88v
Its 7407 ic hex buffer
In input 1.36v
On output 4.88v, strange but on my inafe in post6 0.675c_ddr_vtt_on is connected to 5valw through voltage divider actually r2351 missing so its not divider as you wrote above
Tnx

[mon2]

Re: Dell Inspiron 15 3537 Compal LA-9982P

7407 = open drain buffer. This means the output voltage does NOT have to be the same as the input voltage. Instead, when there is a low on the input, the output will be a low voltage.

If the input is a high voltage ('1' state); the output will float open and an external pull-up resistor will define the output voltage. Respectively, it is safe to have the output pulled-up to a higher voltage than the input range.

The exact datasheet for the 7407 will offer full details.

Being an OD buffer, '0' = '0' (input to output); '1' = 'Z' (high impedance unless the external pull-up resistor is present).

[ziko07]

Re: Dell Inspiron 15 3537 Compal LA-9982P

Thanks MON2 for info

[Techtiger]

Re: Dell Inspiron 15 3537 Compal LA-9982P

7407 = open drain buffer. This means the output voltage does NOT have to be the same as the input voltage. Instead, when there is a low on the input, the output will be a low voltage.

If the input is a high voltage ('1' state); the output will float open and an external pull-up resistor will define the output voltage. Respectively, it is safe to have the output pulled-up to a higher voltage than the input range.

The exact datasheet for the 7407 will offer full details.

Being an OD buffer, '0' = '0' (input to output); '1' = 'Z' (high impedance unless the external pull-up resistor is present).

Merci

[ziko07]

Re: Dell Inspiron 15 3537 Compal LA-9982P

I guess no more tips
Thanks to all tried to help

Regards

[ziko07]

Re: Dell Inspiron 15 3537 Compal LA-9982P

Finally picture comes ON (on broken lcd tested)
Very big thanks to "techtiger"