HP ENVY 750 desktop won't POST

[Larry Sabo]

A replacement motherboard I installed today won't POST and I'm looking for suggestions on what to try before returning the MB. Below is the background. I don't have a compatible CPU nor compatible RAM to swap in -- neither is cheap, so its not feasible to buy them just for testing this PC. Without either, I guess not much I can do other than return the MB or send him to a shop that has these parts.

Can anyone confirm that the "No RAM detected" beeps signify that the BIOS is at least partially functional, and say nothing of the CPU functionality? Anything else I should try?

Background:
The patient is an HP Envy that showed no signs of life upon receipt. Here was my diagnosis:
- "HP ENVY 750 desktop won't power on; no sign of life"
- swap in known-good power supply: no change
- disconnect hard drives, ODD and remove RAM and video card: no change
- verify power switch works okay using VOM between black leads: good
- power switch cable is connected to MB header okay
- motherboard faulty; needs to be replaced (HP IPM17-TP 799926-001; ~$200 CAD del'd)

Today, I replaced the MB but get no POST. Here is what I told the customer:
With the new motherboard, the PC powers on but there is no video output, i.e., it does not POST (power-on self-test). That's using your video card's DVI output with a DVI-VGA adapter but I also tried the HDMI output and another monitor but no change. I also tried another video card but same result. When I remove the RAM, it beeps indicating no RAM detected, so that test is normal. However, I think it only proves the BIOS is functional to some degree -- I don't think it proves the CPU is functional. I don't have a spare CPU to try, unfortunately. I can hear the secondary hard drive spinning but the HDD activity LED never seems to light.

 

[GTP]

Obviously you've tried reseating the ram? Change the position in the slots etc?
But have you reset the BIOS by disconnecting all power cables and removing the BIOS battery for an hour or two?

 

[Larry Sabo]

Yes, I tried one RAM stick at a time, in alternate slots: no joy. Never reset BIOS by removing CMOS battery -- thanks for the reminder! I did measure its voltage: 3.02v so I think it's okay.

PS -- thanks for the reply!

 

[Porthos]

Post the board outside of the case?

 

[Larry Sabo]

Thanks, @Porthos. I knew I should have done that before installing it, but didn't. I'll try that tomorrow.

 

[sapphirescales]

I don't have a compatible CPU nor compatible RAM to swap in -- neither is cheap, so its not feasible to buy them just for testing this PC.

There's no excuse for not having basic replacement parts as a computer tech. All you need is a CPU for each socket type. I don't care if it's a Celeron for $35. It will at least allow you to test to make sure that it is a dead motherboard and not something else. And RAM? How hard is it to have a 2GB DDR3 stick, a 1GB DDR2 stick, and a 4GB DDR4 stick? For a couple hundred bucks you can have every CPU type for every socket and every type of RAM testing stick. This will help avoid buying $200 motherboards you don't need. I mean, it's not like you've gotta buy an i7-8700 for $370 in order to test an LGA1151 socket. This $47 Celeron G3930 works fine for testing 1151 boards:

https://www.bhphotovideo.com/c/product/1304310-REG/intel_bx80677g3930_celeron_g3930_2_9_ghz.html

Buy the cheapest mATX 1151, 1150, 1155, 1156, and 775 socket motherboards you can find and you'll be able to give your clients a CORRECT diagnosis instead of looking like you don't know what you're doing. Better yet? Pick up some cheap kits like this from Microcenter so you can replace BOTH the motherboard and the processor if you don't want to do proper diagnostics:

http://www.microcenter.com/product/...00,_ASUS_Prime_B350M-E_CPU-Motherboard_Bundle

A Ryzen 3 1200 is MORE than plenty for 99% of people. And you can get the processor and an mATX motherboard for $150. I assume you ordered the same low quality piece of junk motherboard that originally came with the HP? That's a great way to get a bad review when it dies in another 12 months because it's JUNK.

In this scenario I would have given my client three options. First off, I would tell them that the quality of the original motherboard is crap, but if they want I can order and install an identical part for $XXX. The second option would be to go with the motherboard/CPU bundle I linked to above for about the same price (maybe a slight premium since they are getting something better in the end). Option #3 would be to trade it in and buy a business unit. I would also recommend an upgraded power supply at the same time because the LAST thing I need is to install a good quality motherboard/processor combo only to have the crappy PSU blow them up 3 months later.

Look, I'm not trying to get on your case here. I have no idea what your business is like or how big or how small you are. I'm just giving you my advice and showing you how I run things. If you're just starting out or on a severely restricted budget for some reason that's one thing. But at the very LEAST you should manage your customer's expectations and let them know that you're 90% positive that it's the motherboard but there's a small chance it could be the processor. Explain to them that you can't afford the testing equipment right now but that if the diagnostic ends up being wrong you won't charge them.

Now as for advice for your problem, seeing as you don't have the proper testing equipment there's not much advice I can offer. It could be the CPU. It might be the memory. It might even be the power switch (unlikely since it turns the unit on, but I've seen it happen. This is why I have a spare power switch I can connect to the motherboard in order to test). It might even be a multitude of problems. Have you tested the PSU itself? Just because it powers a unit doesn't mean it's good to go. A fluctuation in voltage might have fried one or more components. Connecting a good PSU wouldn't make it spring to life in that case. In your exact case, my diagnostic steps would be as follows:

1. Swap RAM
2. While keeping my testing RAM installed I would also swap the GPU
3. While I still have the RAM and GPU installed I would jumper the CMOS
4. I would swap out the CPU with my testing parts still inside
5. If it still wouldn't start I would bench the board and connect my own power switch and PSU
6. Then, and only then would I suspect a bad board. I would then test his CPU and RAM before calling my client and offering my recommendations (as outlined above)

Since you're unable to do this because you don't have the proper parts to test it, all you can do is poke and hope and keep buying replacement parts until the thing magically fires up. God help you if there are multiple issues. There will be no way for you to know. I wish you luck but you really need to be more prepared for situations like this.

 

[Larry Sabo]

@sapphirescales, thanks for taking the time to offer such a detailed and candid reply.

I'm a 1-person, home-based business and will have been in this business for 21 years next month. I usually turn away jobs that I don't have the parts or experience to properly diagnose but I was gambling that the CPU was not at fault, because it so rarely is. With absolutely no sign of life and the other diagnostic steps I described, it was pretty clear to me to be a dead motherboard. Now that I have a somewhat functioning motherboard, it's down to a bad CPU and/or RAM. I've reached out to a former colleague who specializes in MB repairs to see if he has compatible items for testing or is willing to take it from here.

If all else fails, I'll just give the customer the choice of returning the MB for a refund and I will eat the cost of diagnosis and shipping, or keeping it and taking the PC to a shop better equipped to deal with the problem. I tried to discourage him from pursuing the MB replacement but he was determined to proceed. Anyway, I'll update the thread with the outcome once the dust settles.

 

[Kirby]

It is always possible that when one part goes out it takes another with it. This used to be exceptionally common in Emachines. When the PSU died it often sent a surge through the MB and fried it too.

I would at least try your known-good power supply with the new board. Also, you might have a test CPU and RAM in your own computers, if you don't mind a little more work. When I have a weird problem like this I like to remove the CMOS battery, unplug it, hold in the power button for about 30 seconds and then let it sit at least 20 minutes with no power. Overnight is better. Even the power supplies have electronics in them these days susceptible to built-up charge holding open some transistor "switch". With the CMOS cleared you should get a different POST beep and message as it wants you to set up the BIOS for the first time.

Lastly, you need a "minimum fee". It doesn't have to be much, but it should cover at least a good portion of any costs you might otherwise have to eat. Mine is $22.50, 1/2 hour of labor. People bring you their computers to be "fixed", but just "fixing" computers is not what you do. You also diagnose them. Your time, regardless whether the computer ultimately gets "fixed" or not, is worth something. It's not like this is a car where the bill may be thousands of dollars and you'll make a few hundred in profit. Best-case-scenario, which rarely happens, you're looking at maybe a couple hundred dollars in profits. Usually you're looking at far less. So you need to make something on everything. I learned long ago that if you don't charge people for diagnosis they will find out what's wrong for free and buy the part themselves on Amazon to fix it because it's cheaper. People will use you if you let them.

As an example of that, I offer a place for people to drop of electronic recycling because I have a guy that will pick it up from my at no charge. I pick through everything that comes in. If it's useful, or even maybe someday it might be, I hold on to it. I give these parts to people free of charge. I didn't pay for them, after all. I used to just give them freely. Not any more. Now you can get all the used parts you want, but WITH the labor to install them at regular rate. First, it has increased my business. People like getting something for free and if the parts are free, I can sometimes fix a computer much cheaper than it would normally cost. Many times that has made the difference between me being able to charge full price to fix it or just my minimum fee to diagnose it. But here is the REAL reason you can't just come in and get a free part any more. Before I started offering free used parts only with service, I had a guy who had never bought anything with me call me on my cell phone on a Sunday to come down and open my shop just to give him a free stick of RAM. I had another guy who had gotten more free parts and more free advice from me than, literally, any 10 other customers combined. He, too, had never spent a dime with me. There are many people out there who are inconsiderate a-holes. They will take and take and take and never give anything back. There used to be a group of ladies in town that would go from business to business on the first of every month to get whatever was free. Pens, calendars...essentially whatever promotional material was free. But they never patronized the businesses. So you HAVE to have a minimum fee. The customers who don't ever want to pay are the most demanding and the least considerate people you will ever meet. They seem to have no concept whatsoever of personal space or time or how business works or why you would be in business, nor do they care one bit whether your business succeeds or fails. The great thing about a minimum fee is that when these people get a bill, they go away and never come back.

 

[Larry Sabo]

Thanks for your reply, @Kirby. I have a minimum fee of 1 hr ($60 CAD). However, I would waive that in this case rather than leave a soured customer, if that's what it takes.

As soon as my bench is cleared from a job in progress, I'll try the MB out-of-chassis and clear the CMOS, as has been suggested by you and others, and will also try the memory in the high-end slots, as suggested by my colleague. (He has had the identical problem with one of these and moving the memory to the high-end slots was the fix in his case. I doubt it's relevant here, given that a known-good video card was tried so shared memory for video is not likely to be an issue, but I'll try it anyway.) I'll also continue testing with another known-good PSU, even though the original put out all correct voltages, according to my original tests.

My worst fear is that it was a PSU glitch that killed the MB and memory/CPU and is waiting to repeat itself after I fix it. <sigh> I've also had HP MBs that have MOSFETs that just die for unexplained reasons. It's such a PITA to test them because you need to do it out-of-circuit, so buying a replacement board was the chosen solution.

 

[sapphirescales]

Thanks for your reply, @Kirby. I have a minimum fee of 1 hr ($60 CAD). However, I would waive that in this case rather than leave a soured customer, if that's what it takes.

Good decision. If you can't fix the problem, then they shouldn't get a bill. Note that there's a HUGE difference between you not being ABLE to fix the problem and the client CHOOSING not to fix the problem (which they usually choose not to if the expense is too high). I run into things I'm not able to fix at times because I don't have the necessary skills/experience. I don't charge my clients if I can't fix their problem. I'm up front with them and they appreciate my honesty.

As for your experience, I would highly recommend that you buy those parts to test with. You absolutely MUST invest back into your business or you'll run into problems like this that you can't fix. I know, I know, the chances of a bad CPU is much lower than a bad motherboard, but with the crappy quality of newer OEM computers you have to be absolutely SURE that it's not something more serious. I wouldn't be surprised if you had a bad PSU, motherboard, processor, and RAM. Maybe even a bad graphics card too. Even if you order one of these parts to see if replacing that single part fixes it, you'll never get the thing to POST because there are multiple issues.

You're not out that money that you invest in these testing parts. Eventually when the parts get so old that you don't really see systems in anymore with those parts, you can sell them to your next client. I sold my LGA775 socket motherboard about a year ago for $200 to a client that was desperate to keep his existing computer for as long as possible. I originally paid $50 for that motherboard. But since 2016 if ANYTHING comes in with an LGA775 socket processor, I recommend either upgrading the motherboard/processor/RAM or trading the system in for something else.

 

[Larry Sabo]

I don't charge my clients if I can't fix their problem. I'm up front with them and they appreciate my honesty.

Same here. Regarding having those parts on hand to deal with things like this, it just doesn't make sense for me, given the limited opportunity for me to put them to use. If I were younger, sure.

I'll be taking the system to my colleague who does have tons of parts, plus the skills and experience to deal with it. (He's a retired DEC engineer.) Clearing the CMOS by removing the battery and discharging the circuit, and moving the memory to the high-end slots, brought no joy.

 

[GTP]

There's no excuse for not having basic replacement parts as a computer tech. All you need is a CPU for each socket type. I don't care if it's a Celeron for $35. It will at least allow you to test to make sure that it is a dead motherboard and not something else. And RAM? How hard is it to have a 2GB DDR3 stick, a 1GB DDR2 stick, and a 4GB DDR4 stick? For a couple hundred bucks you can have every CPU type for every socket and every type of RAM testing stick. This will help avoid buying $200 motherboards you don't need. I mean, it's not like you've gotta buy an i7-8700 for $370 in order to test an LGA1151 socket. This $47 Celeron G3930 works fine for testing 1151 boards:

https://www.bhphotovideo.com/c/product/1304310-REG/intel_bx80677g3930_celeron_g3930_2_9_ghz.html

Buy the cheapest mATX 1151, 1150, 1155, 1156, and 775 socket motherboards you can find and you'll be able to give your clients a CORRECT diagnosis instead of looking like you don't know what you're doing. Better yet? Pick up some cheap kits like this from Microcenter so you can replace BOTH the motherboard and the processor if you don't want to do proper diagnostics:

With all due respect, that's hogwash!
I'm a one man show and I can assure you I don't have parts lying around "for testing purposes!"
If the job gets beyond my control I outsource to people who do have and can afford to have hundreds or thousands of dollars worth of parts lying around.
And before you start on about my ability to properly diagnose faults, I've managed ok for 20 years.
And besides, how much time do you waste fooling around trying to find a fault when the cost of a replacement part is so much less?

 

[sapphirescales]

With all due respect, that's hogwash!
I'm a one man show and I can assure you I don't have parts lying around "for testing purposes!"
If the job gets beyond my control I outsource to people who do have and can afford to have hundreds or thousands of dollars worth of parts lying around.
And before you start on about my ability to properly diagnose faults, I've managed ok for 20 years.
And besides, how much time do you waste fooling around trying to find a fault when the cost of a replacement part is so much less?

It's not about time. I can do this entire diagnostic procedure in less than an hour. All you need is to have the proper parts for testing. I'm sorry, but just because you've managed to get by without having the proper testing parts doesn't mean that's a good thing to do. There are pizza techs that manage to work out of their $450/month apartments in the middle of dumpville. That doesn't mean that's something you should strive for. I'm not saying that you're a pizza tech (I know better), but the more often you're able to give proper diagnostics the better. You just can't do that without proper testing parts.

There are cases where proper diagnostics aren't worth doing. For example, it's usually not a good idea to devote 24 hours of bench time to testing memory when you can swap the RAM out for $40. And you can usually look back on the blue screens so you know which direction to start in (in this case, memory). I consider testing parts to be as essential as screwdrivers and diagnostic software when running a computer repair business. Making guesses about what's wrong and buying $200 parts to see if you're right is NOT acceptable. Even if you're willing to bite ALL the costs, time is more important than anything, and your client is without their computer while you hope and poke around because you can't be bothered to spend a few hundred $$$ on proper testing equipment. I can't imagine I'd have much business if it took me weeks to do a simple diagnostic and repair like this while I make educated guesses and wait around for parts to be shipped just so I can try and see if it fixes the problem.

Maybe the OP doesn't see too many desktops, or maybe he's usually working with businesses where everything is always under warranty or something. I don't know his situation. All I know is that not having the proper equipment to test computers is as ridiculous as a car mechanic not having the tools to work on anything other than changing the oil. If you want to do that, open an oil change business. But don't proclaim to do transmission repair when all you can do is change the oil because you don't have the proper tools. I'm sorry but the truth is harsh. We're all here to better ourselves and share advice and that's all I'm trying to do.

As for your comment on outsourcing, you would seriously send a desktop to someone else so they can properly test it for you? Desktops are the easiest, most basic thing for a computer technician to work on. And seeing as all the parts are modular and universal, there is absolutely NO EXCUSE for not having a few parts around to test and make sure your diagnosis is correct before you waste HUNDREDS of dollars and days/weeks of your client's time by buying unneeded parts.

I can't tell you how many times I've had people bring computers into my shop for a second opinion because another shop told them their motherboard or some other part is shot and it turned out to be an incorrect diagnosis. Did they intentionally mislead their client to try and get more money out of them? Maybe. Maybe not. But I can tell you that when something like this happens, people do NOT give that shop the benefit of the doubt. If you don't have the proper testing parts, you can NOT arrive at a correct diagnosis in a lot of cases. You're just making a guess about what's wrong. And if your client finds out you gave them an incorrect diagnosis, there'll be h*ll to pay.

 

[GTP]

Making guesses about what's wrong and buying $200 parts to see if you're right is NOT acceptable.

I doubt there would be anyone who actually does this.

I can't imagine I'd have much business if it took me weeks to do a simple diagnostic and repair like this while I make educated guesses and wait around for parts to be shipped just so I can try and see if it fixes the problem.

...or this.

It's not about time.

It IS about time. And saving the clients time as well.
Keeping a couple of ram sticks, PSU's and HDD/SSD's or a few cables for diagnosis is a no brainer, but keeping all that other stuff you suggest?
I think not!

 

[sapphirescales]

Keeping a couple of ram sticks, PSU's and HDD/SSD's or a few cables for diagnosis is a no brainer, but keeping all that other stuff you suggest?
I think not!

All what? 4 motherboards and CPU's? 6 if you include AMD. These don't have to be expensive. $40 to $50 apiece and you're good to go. You're not building a gaming rig here. Cheapo Celeron's and low end AMD's are all you need for the processors.

I doubt there would be anyone who actually does this.

What are you talking about? That's EXACTLY what the OP did! He didn't know for sure that the motherboard was at fault. He knew it was more likely the motherboard than the CPU, but he didn't even have any RAM to swap out! "Oh, I think it's the motherboard. Let me go buy a $200 board, wait a few days for it to get shipped, and hope it works!"

Let's say it DID turn out to be the motherboard, but the one he got didn't work. Maybe it got bumped around in shipping or was just faulty from the factory. He'll never know that because he wasn't able to CONFIRM the diagnosis of a bad motherboard using testing parts! Now he's going to think it's something else and buy some RAM. Then that doesn't work because it was the motherboard all along! Then he'll try something else, and before you know it, it's been a freaking WEEK since his client dropped it off and it's still deader than a doornail. Then maybe he throws his hands up and tells them it's toast and they go and get a second opinion. They take it to someone that actually has the parts they need to PROPERLY diagnose the system, and learn that it was, in fact, the motherboard. This guy can get them back up and running same or next day with a better quality board for much less than buying a new system. THIS HAPPENS ALL THE TIME IN MY SHOP.

Look, I know this kind of thing doesn't happen on a daily basis, but you have GOT to be prepared for it! Testing parts are CHEAP! MUCH cheaper than getting bad reviews or losing clients because you're giving out incorrect diagnostics and taking too long to get the system back to them.

 

[mikeroq]

I have to agree with sapphire. Having some parts on hand to test with is invaluable. I don't really have "current" stuff but I have I some. I'm hoping to get more here soon. Currently have motherboards LGA775, AM3, LGA1156, LGA1155. I have various processors up to LGA1155, an AMD APU, AMD FX (pulled from a dead machine). DDR, DDR2, DDR3, 1 stick of DDR4 currently. I even have a decent 750W PSU in case I need to power a higher end system. Couple graphics cards too. Besides the power supply that is mine, almost everything else I have is a pull from computers left behind, upgraded, or replaced.

While you can "guess" whats wrong, it helps to be able to narrow it down to be sure. If you think the ram is causing the issue, it's quick to just swap it out and see. Think the motherboard is bad? Put their ram and CPU in your board and find out. Think their processor is bad (only had a handful) pop one in and find out.

I've seen posts here of people buying part after part to try to fix something.

 

[Larry Sabo]

This is a great topic with lots of good replies. They are all much appreciated.

 

[Kirby]

...If you can't fix the problem, then they shouldn't get a bill. Note that there's a HUGE difference between you not being ABLE to fix the problem and the client CHOOSING not to fix the problem...

A good point. In this case, however, I would have been upfront with them and it sounds like the OP actually tried to dissuade them from doing this. Under that circumstance I would feel totally justified charging my minimum fee. Again, my time is worth something. Customers will have you waste all kinds of time and money on a longshot if they think you're the only one who's going to pay for it.

That is why I ALWAYS charge the minimum fee. I just try to be upfront with the customer, tell them what I think the chances of success are and, if I don't have a good feeling about it as was the case here, I tell them that I don't like the chances of success, but I would have to charge for my time to try. In the best case I can think of I once spent 3 weeks scanning and re-scanning a hard drive trying to recover data. One of only 2 computers I had was tied up for 3 weeks, which slowed down my work. On day one I told the customer that it didn't look good. But it wasn't me who made the decision to go ahead anyway, it was the customer, against my recommendation. If I'm going to work for you for 3 weeks to get the result I told you you'd likely get on day one, you're getting a bill.

 

[GTP]

I do keep some parts on hand like a couple of desktop/universal laptop PSU's, several ram chips, (DDR2, DDR 3, and a DDR4 x 4gb and also the same in SODIMM) an el cheapo graphics card and few other bits for diagnosing issues, but I don't keep motherboards or CPU's.
I also keep these parts new in stock, just in case I need them.
In twenty years I've had one faulty CPU and that was my own Intel Core 2 Duo from about 2005? Even ram issues are rare.
As I said it is far easier, quicker and more cost effective for the client and for me to outsource (suspected) motherboard issues that I feel - after a cursory inspection and some basic tests - should be sent off to someone who has the skills and equipment to give a proper diagnosis rather than me guessing.

 

[Larry Sabo]

My former DEC colleague has determined that the on-board GPU is the problem. When he applies pressure to the attached heat sink, he gets video. The customer has decided to have him repair it, rather than wait 10-14 days for a replacement.