HP 6735b - Black screen - caps lock + num lock blink 5 times
Pseudo
-
BravoBetC -
BravoBetC -
Hello,
I experienced the following issue with a HP 6735b laptop that has been out of warranty for 4 months. Windows Vista.
On Monday evening, I shut down my laptop, which was connected to its docking station normally. No problems or remarkable events.
On Tuesday evening, when I picked up my computer without having moved or used it since (no shock, no water accident, or anything else), I attempted to turn on my laptop: the screen was completely black. No backlight, no flash or flicker on the screen. The fan is running. You can hear the hard drive spinning. Some indicators light up on the laptop. Among other things, the caps-lock and num-lock lights blink 5 times over a period of 10 to 15 seconds. Then nothing. The same symptom occurs on an external screen.
The question: what to do?
Here is a report of my process that led to a solution for 3 Euros.
Configuration: Windows Vista / Firefox 17.0
I experienced the following issue with a HP 6735b laptop that has been out of warranty for 4 months. Windows Vista.
On Monday evening, I shut down my laptop, which was connected to its docking station normally. No problems or remarkable events.
On Tuesday evening, when I picked up my computer without having moved or used it since (no shock, no water accident, or anything else), I attempted to turn on my laptop: the screen was completely black. No backlight, no flash or flicker on the screen. The fan is running. You can hear the hard drive spinning. Some indicators light up on the laptop. Among other things, the caps-lock and num-lock lights blink 5 times over a period of 10 to 15 seconds. Then nothing. The same symptom occurs on an external screen.
The question: what to do?
Here is a report of my process that led to a solution for 3 Euros.
Configuration: Windows Vista / Firefox 17.0
1 réponse
Here is a complete amateur approach. Without any prior experience in dismantling laptops. It's long, with some risks, and no guarantee. It's very inexpensive. The biggest problem is asking the right questions. The second major issue is that very few shops take on this kind of attempts or they charge a lot. Of course, I don't want to buy specialized equipment. All the repair shops contacted tell me: throw it away and buy new. It infuriates me. So I pay in hours and risks. But at least I'm learning and trying to save functional equipment.
This solved my problem 100%. But for how long...? The future will tell.
*) My computer is out of warranty
I don't even try to contact HP (who previously changed the motherboard for a sound issue, without discussion while the warranty was still valid. :-) It didn't actually solve the problem (that I resolved myself: bunch of incompetents! :-( )
*) The first 20-second search: a failure.
I stumble upon some ridiculous stuff. The motherboard in the oven trick. Yes, 10 minutes at 180°C. For example https://www.youtube.com/watch?v=rLSqBpndSGM I abandon it for now: without understanding why and without a solid logic, I refuse to try it.
*) First, absolutely describe the symptom precisely
Before searching, describe your symptom. Everything: the noises, the sounds, the lights, the particular absences of events, the last 24 hours. This greatly helps in searching when you don't know what to look for. You have my symptoms in the question.
*) Find expertise randomly
The lucky break: commercial companies have the expertise _and_ publish it
1) http://www.reparation-carte-mere-hp.fr/panne-carte-mere-portable-hp-compaq-6735b.htm. It's a huge help, as it allows me to attempt an approach. In my case: frequently encountered issues with power connectors, graphics cards soldered to motherboards. I called these people: they take care of it for around 250 Euros.
2) A second highly suspicious site given the poor grammar and spelling, nevertheless allows me to cross-reference the information http://www.bluereparation.com/reparation/reparation-cartes-graphique.html,
*) Specify the symptom formally
Find the manufacturer's documentation that allows you to refine/confirm the understanding of the symptom: "Error codes of indicators associated with a blank screen"
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01900144&lc=fr&cc=fr&dlc=fr/
It's a second independent clue that seriously points to a hypothesis: the motherboard is malfunctioning. But what.
*) Methodically reproduce the symptom
Dismantle with flat, cross, and torx screwdrivers. Be careful: you void the warranty by doing this (you won't be able to lie about it because the screws are under warranty seals, which you will break.)
Without experience, it's not an obvious question at all. For disassembling, when you don't know where and when to apply force - and it's officially necessary sometimes - to unclip "things", it's really difficult to dare. So, some disassembly videos on YouTube for the model closest to yours + the lucky break "the manufacturer's disassembly documentation" here http://h22235.www2.hp.com/hpinfo/globalcitizenship/environment/productdata/Countries/_MultiCountry/disassembly_notebo_200882734228.pdf + very cautious testing not without risks.
You need to remove as many components as possible and reproduce the symptom. In my case, I reproduced it after removing: HDD, CD/DVD, all the memory, keyboard, Wi-Fi card, PCMCI connector, SD connector, CPU, batteries, microphone/headphone connector, touch pad, docking station, changed power supply unit.
It is essential to be methodical: stick all the screws on paper, identify their locations for reassembly.
*) Find 3 much more precise videos on these heating stories
1) "How to apply hot air to solder a video chip"
https://www.youtube.com/watch?v=ExB1l-jBOoA
It shows that hot air soldering tools exist. So we will heat "something" that is not the CPU. This "something" is a soldered chip (that's why it can't be "simply replaced"). That you need to protect the motherboard and how. That this chip we are going to tamper with is probably under a heat sink, so you need to disassemble it, you will also need to restore thermal conduction between the chip and radiator with a "thermal compound" (thermal paste), so you must have this paste (findable in computer media/hi-fi supermarkets)
2) HP black screen repair - "HP Pavilion DV6000 Blank Screen Repair"
https://www.youtube.com/watch?v=YLfAPWLcNxQ
An excellent video. I take away: a complete disassembly approach. What to look for (it's silly, but when you don't know what you're looking for, it's hard to find). Another way to protect the motherboard. You can attempt soldering with another tool: a gas soldering iron. The importance of thermal conduction (cleaning + restoration: I can't ignore this detail). I notice that his equipment is super light: I like that as an amateur who doesn't want to equip myself.
3) How to do things correctly
https://www.youtube.com/watch?v=A3ZAePt-kBI
We cannot do this, as we don't have the equipment. But we finally understand these oven stories and roughly what we are trying to achieve.
*) Look for pros in the area who could do the tinkering more reliably than I can (because honestly: I don't want to try it myself.)
First: The shops understand my question "could you reflow a GPU (Graphical Processing Unit) onto my laptop motherboard? (Could you reflow (or reball) my GPU onto my motherboard?)" It's rather positive. :-) But they all tell me: no. You should throw the broken laptop away and buy new. THIS ANNOYS ME! :-)
Secondly, after a long phone/internet treasure hunt, it turns out that: no, the so-called specialized laptop repair shops are not good interlocutors. :-( But... in a pretty unexpected way, other people know the problem and understand my annoyance. For example, "La Bonne Combine" in Lausanne does _NOT_ do the repair (no need to call) but the technician on the phone understands and testifies to having seen a heating trick work.
Thirdly: The same treasure hunt, but worse, makes me hear something about the store "Informatika" in Geneva. The guy is nicknamed the Dr. House of computers in press articles. He's not in the directories and doesn't have a website. I'm pleased: there are still fighters who fight for repair. I can't reach him by phone.
*) Action.
Finally: I make a risky assumption after all this research. What I need to do: reflow my graphics chip to my motherboard. How: several educational disassemblies and reassemblies. I try with a hairdryer: symptom unchanged. I bet it's not hot enough. My father lends me a tiny gas torch + aluminum strips to protect the motherboard. I heat for 45 seconds, let it rest for an hour. The symptom (without full reassembly) changes! 3 blinks instead of 5. :-) But still black screen :-( I apply thermal paste, then reassemble everything. I test.
It works. :-))))
Cost: 3 euros for thermal paste. 10 hours of research.
Tools: small gas torch, screwdrivers (flat, cross, torx), tape, paper, small aluminum plates for protection.
Reliability: it's hit or miss, at your own risk.
Conclusion.
Tinkerers can attempt, but it's really long, risky, and not guaranteed. Someone with a lot of experience might manage everything in 1.5 hours without reliability. If you can't find someone willing to attempt, then give the old computer to be recycled properly or sell spare parts. I understand that pros charge dearly for doing this: the only way to guarantee a result is to have big equipment and ultimately to change the motherboard (additional costs of course). I am, of course, convinced that manufacturers' labs have the test benches that allow a certain diagnosis in 10 seconds, and the tools to make repairs. But it's like usual: repairing this part to see another fail 3 months later... it's not necessarily defensible.
This solved my problem 100%. But for how long...? The future will tell.
*) My computer is out of warranty
I don't even try to contact HP (who previously changed the motherboard for a sound issue, without discussion while the warranty was still valid. :-) It didn't actually solve the problem (that I resolved myself: bunch of incompetents! :-( )
*) The first 20-second search: a failure.
I stumble upon some ridiculous stuff. The motherboard in the oven trick. Yes, 10 minutes at 180°C. For example https://www.youtube.com/watch?v=rLSqBpndSGM I abandon it for now: without understanding why and without a solid logic, I refuse to try it.
*) First, absolutely describe the symptom precisely
Before searching, describe your symptom. Everything: the noises, the sounds, the lights, the particular absences of events, the last 24 hours. This greatly helps in searching when you don't know what to look for. You have my symptoms in the question.
*) Find expertise randomly
The lucky break: commercial companies have the expertise _and_ publish it
1) http://www.reparation-carte-mere-hp.fr/panne-carte-mere-portable-hp-compaq-6735b.htm. It's a huge help, as it allows me to attempt an approach. In my case: frequently encountered issues with power connectors, graphics cards soldered to motherboards. I called these people: they take care of it for around 250 Euros.
2) A second highly suspicious site given the poor grammar and spelling, nevertheless allows me to cross-reference the information http://www.bluereparation.com/reparation/reparation-cartes-graphique.html,
*) Specify the symptom formally
Find the manufacturer's documentation that allows you to refine/confirm the understanding of the symptom: "Error codes of indicators associated with a blank screen"
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01900144&lc=fr&cc=fr&dlc=fr/
It's a second independent clue that seriously points to a hypothesis: the motherboard is malfunctioning. But what.
*) Methodically reproduce the symptom
Dismantle with flat, cross, and torx screwdrivers. Be careful: you void the warranty by doing this (you won't be able to lie about it because the screws are under warranty seals, which you will break.)
Without experience, it's not an obvious question at all. For disassembling, when you don't know where and when to apply force - and it's officially necessary sometimes - to unclip "things", it's really difficult to dare. So, some disassembly videos on YouTube for the model closest to yours + the lucky break "the manufacturer's disassembly documentation" here http://h22235.www2.hp.com/hpinfo/globalcitizenship/environment/productdata/Countries/_MultiCountry/disassembly_notebo_200882734228.pdf + very cautious testing not without risks.
You need to remove as many components as possible and reproduce the symptom. In my case, I reproduced it after removing: HDD, CD/DVD, all the memory, keyboard, Wi-Fi card, PCMCI connector, SD connector, CPU, batteries, microphone/headphone connector, touch pad, docking station, changed power supply unit.
It is essential to be methodical: stick all the screws on paper, identify their locations for reassembly.
*) Find 3 much more precise videos on these heating stories
1) "How to apply hot air to solder a video chip"
https://www.youtube.com/watch?v=ExB1l-jBOoA
It shows that hot air soldering tools exist. So we will heat "something" that is not the CPU. This "something" is a soldered chip (that's why it can't be "simply replaced"). That you need to protect the motherboard and how. That this chip we are going to tamper with is probably under a heat sink, so you need to disassemble it, you will also need to restore thermal conduction between the chip and radiator with a "thermal compound" (thermal paste), so you must have this paste (findable in computer media/hi-fi supermarkets)
2) HP black screen repair - "HP Pavilion DV6000 Blank Screen Repair"
https://www.youtube.com/watch?v=YLfAPWLcNxQ
An excellent video. I take away: a complete disassembly approach. What to look for (it's silly, but when you don't know what you're looking for, it's hard to find). Another way to protect the motherboard. You can attempt soldering with another tool: a gas soldering iron. The importance of thermal conduction (cleaning + restoration: I can't ignore this detail). I notice that his equipment is super light: I like that as an amateur who doesn't want to equip myself.
3) How to do things correctly
https://www.youtube.com/watch?v=A3ZAePt-kBI
We cannot do this, as we don't have the equipment. But we finally understand these oven stories and roughly what we are trying to achieve.
*) Look for pros in the area who could do the tinkering more reliably than I can (because honestly: I don't want to try it myself.)
First: The shops understand my question "could you reflow a GPU (Graphical Processing Unit) onto my laptop motherboard? (Could you reflow (or reball) my GPU onto my motherboard?)" It's rather positive. :-) But they all tell me: no. You should throw the broken laptop away and buy new. THIS ANNOYS ME! :-)
Secondly, after a long phone/internet treasure hunt, it turns out that: no, the so-called specialized laptop repair shops are not good interlocutors. :-( But... in a pretty unexpected way, other people know the problem and understand my annoyance. For example, "La Bonne Combine" in Lausanne does _NOT_ do the repair (no need to call) but the technician on the phone understands and testifies to having seen a heating trick work.
Thirdly: The same treasure hunt, but worse, makes me hear something about the store "Informatika" in Geneva. The guy is nicknamed the Dr. House of computers in press articles. He's not in the directories and doesn't have a website. I'm pleased: there are still fighters who fight for repair. I can't reach him by phone.
*) Action.
Finally: I make a risky assumption after all this research. What I need to do: reflow my graphics chip to my motherboard. How: several educational disassemblies and reassemblies. I try with a hairdryer: symptom unchanged. I bet it's not hot enough. My father lends me a tiny gas torch + aluminum strips to protect the motherboard. I heat for 45 seconds, let it rest for an hour. The symptom (without full reassembly) changes! 3 blinks instead of 5. :-) But still black screen :-( I apply thermal paste, then reassemble everything. I test.
It works. :-))))
Cost: 3 euros for thermal paste. 10 hours of research.
Tools: small gas torch, screwdrivers (flat, cross, torx), tape, paper, small aluminum plates for protection.
Reliability: it's hit or miss, at your own risk.
Conclusion.
Tinkerers can attempt, but it's really long, risky, and not guaranteed. Someone with a lot of experience might manage everything in 1.5 hours without reliability. If you can't find someone willing to attempt, then give the old computer to be recycled properly or sell spare parts. I understand that pros charge dearly for doing this: the only way to guarantee a result is to have big equipment and ultimately to change the motherboard (additional costs of course). I am, of course, convinced that manufacturers' labs have the test benches that allow a certain diagnosis in 10 seconds, and the tools to make repairs. But it's like usual: repairing this part to see another fail 3 months later... it's not necessarily defensible.
Keywords: failure, laptop, HP 6735b, black screen, solution, repair, amateur
The repair lasted a month until January 20, 2013. Same scenario: I'm watching a movie (i.e., intensive graphics usage of the computer). Everything is fine. I shut down the computer without any issues. It won't turn on again. Same symptoms.
I applied exactly the same fix again on February 1, 2013, but by heating the graphics chip for 60 seconds instead of 45. It fixed it again. Until when? The future will tell me.
See you later!