HP dv7-7133nr No Video Problem Goya/Balen

[alextech]

I have a hp Goya Balen motherboard, I am a beginner to repairing motherboards. The motherboard turns on but no video, also this motherboard does not have a GPU. The question I would like to ask is what do I have to look for? It seems to me like most people would think that the problem would be the GPU, but I know it would not be that. I have checked the capacitors under the CPU and some appeared to be shorted to ground, but to make sure it wasn't I took it off the board and they were not shorted to ground. I am curious if this would be a resistor or a bios issue? I did find a schematic for Goya/Balen, but the schematic is for motherboards with GPU.

[SMDFlea]

Re: HP dv7-7133nr No Video Problem Goya/Balen

Post a close up picture of the area around PU4002 ,SPR5,PL4001 , and a second picture to the right of PL4001

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

It was kind of hard to get a focus when getting close, is this good enough? I checked the coil and there is open line and no beep on that coil. I do see like a little black dot between PU4003 and PL4001, not sure if its a burn or not.

[SMDFlea]

Re: HP dv7-7133nr No Video Problem Goya/Balen

Clean up that whole area with a brush and 100% IPA alcohol. Check voltage on PU4004 and PU4006 pins 1,4,8 . Use the attatched schematic for reference

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

Ok I have an update, apparently when I was checking the board I accidently shorted a capacitor with the dc in connector and resulted in no power. I shorted a cap that I touched and a diode 330 that I did not and replaced but still have no power. I bought a power supply to see if it could help me find a bad component. I checked for voltage on PU4004 AND PU4006. It appears that all pins have 3 to 4 volts except for pu4006 top pins have 19v. the volts are jumping back and forth by 1 on the 3 to 4 volts. I have not looked at the schematics just yet, I have been busy. I will get back once I have time.

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

Ok so I decided to make 2 videos to see whats really going with volts and continuity:

Continuity mode - https://youtu.be/BoEGsMrGTMg
Volts mode - https://youtu.be/khCbiGNBne8

[SMDFlea]

Re: HP dv7-7133nr No Video Problem Goya/Balen

Its likely that PU4006 is damaged. Remove PU4006 and PU4004 from the board and test them .

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

Ok I was not sure how to test PU4006, so what I did was check continuity on pins 1 2 3 and 4 and there is no beep. Also I saw a video of a very similar board with no power and had same PU4006 transistor and he basically jump the other side to pin 2 and he had power. However I tried that and it did not work. After putting the transistors back, I am now getting 12 and sometimes 15 volts on PU4004 leg 1, but on pin 2 3 4 5 6 7 8 are 1.2 and sometimes 1.5 volts. How is this possible? Also I checked coils in ohms and the back of the board all have open line, but in the front there about 100 ohms.

Here is video checking ohms: https://youtu.be/DzV8nn04Yz4
Here is mb similar problem: https://youtu.be/mAFrdkbnTz0

I have ordered transistors and will change if needed.

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

Correction: PU4004 pins 1 2 3 4: .3 and .4 v (jumping up and down)
5 6 7 8: .9 volts
PU4006: pins 1 2 3 4: .3 and.4 v (up and down)
Pins 5 6 7 8: 19 v

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

Ok, so I replaced the PU4006 and PU4004 and still no power. The reading on PU4006 leg 5 6 7 8 is 19v and the 1 2 3 4 are no volts. The reading on PU4004 leg 5 6 7 8 are .9 volts and leg 1 2 3 4 are no volts. The volts are not going up and down anymore. Would I need to use a power supply to load amps on PU4006?

[SMDFlea]

Re: HP dv7-7133nr No Video Problem Goya/Balen

No ,don`t inject power just yet. Check volts on pin 6 of PU4001, then disconnect all power and test ohms to gnd on pins 1,2,3,4 and 6 .

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

Ok, so you said PU4001, I think you probably meant PU4002? There is no PU4001 on this board. I took pictures to clarify what you meant. A little bit dirty due to the unclean flux I put. Another note PC4025 has 66 k Ohms on one side but the problem it not the capacitor itself.

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

Ok, so when you said PU4001, I believe you were referring to BQ738

Ok PIN 1 on BQ738/BQ24738 (same), schematics says its PU4001 but on mb is not shown.
VOLTS:
PIN 1 - .9 v
PIN 4 - no volts
PIN 6 - no volts

OHMS:
PIN 1-4 Open Line
PIN 6 60 k ohms

[SMDFlea]

Re: HP dv7-7133nr No Video Problem Goya/Balen

PC4010 looks burnt. SC2D2U25V5KX , 2.2uf 25V .Replace it and do the same tests.

EDIT: PQ4003 on the board looks like it has a burn mark on the top

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

PC4010 and PQ4003 looks like that because of the no clean flux I used, I thought I bought the flux I was looking for like they use at my job but it wasn't. I put too much thats why it looks like that, I left a note for that. I will try to clean it more. PC4010 I was going to replace but realized there was still 66 k ohms on the board, so I decided to put it back. I need to check SC2D2U25V5KX, Is this not shown on the picture or are you referring to PC4010? I will replace PC4010 just in case though.

[SMDFlea]

Re: HP dv7-7133nr No Video Problem Goya/Balen

PC4010 is on the board.On your picture at post #12 it looks burnt or its not seated across both pads. PC4010 on the schematic has the part number SC2D2U25V5KX.You need to replace the BQ24738 , its not going to be easy though if you`ve never soldered a QFN IC before.Practice first on some other scrap boards,watch youtube videos, use plenty of flux and a fine tip on the soldering iron.

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

PC4010 is on the board.On your picture at post #12 it looks burnt or its not seated across both pads. PC4010 on the schematic has the part number SC2D2U25V5KX.You need to replace the BQ24738 , its not going to be easy though if you`ve never soldered a QFN IC before.Practice first on some other scrap boards,watch youtube videos, use plenty of flux and a fine tip on the soldering iron.

Thanks for letting me know to practice on that one, I will practice with some scrap boards before I change it. I replaced PC4010, should look a lot better now.

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

Ok I changed BQ738 and here is the volts and ohms on the pins, still wont power on:
1 .9 v
4 30mV
6 2.6 v

1 4 ohms
2 4 ohms
3 4 ohms
4 OL
6 60 k ohms

Also I have a pic where the short happened and the BQ738 IC chip that I replaced:

[Techtiger]

Re: HP dv7-7133nr No Video Problem Goya/Balen

BQ24738 is not correct

pin 1=19v
pin 2=19v
pin 3=19v
pin 4= must be high to operate N Channel mosfet to by pass voltage above 20V
pin 6=2.7v

remove PT4601 cap and test it

[alextech]

Re: HP dv7-7133nr No Video Problem Goya/Balen

I forgot to mention PT4601, I did tested it when I removed and was short and I did replace.