Both ram modules don't work in the same time

A matched pair, in which both RAM sticks are produced and purchased from a vendor as a pair, is a more reliable route to success. Sometimes a seemingly-compatible stick won't play nicely with other RAM.

It's not totally clear from your post, but I would want to know if a matched pair worked in your laptop. Did it? If it did, then we'd know that the slots are fine. And if the second RAM stick you tried will work on its own, then we'd know that it is fine and your original stick is fine (since you were using it). Did the second RAM stick work on its own? If all that is true, then it's simply that your new stick doesn't play well with your old stick, and that's not uncommon.

I would suggest trying another stick, ensuring that it has the same frequency and timings as your original stick. Sometimes a stick with more aggressive timings won't work with another stick.

If you cannot find a stick that works with yours, you may be faced with getting a matched pair.

Hi there,

This is Ourab, one of the supervisor with Dell's Social Media team.
I understand that you are facing issues with the system not booting up
We would like to look into this in detail and assist you. However, I see you may have stepped away at the moment.
We will wait for you to get back to us with an update, so we can take this further. We are open 24/7 and will be more than happy to continue where we left off

Thank you again for your patience and understanding.
Ourab Paul
Supervisor
Dell Social Media

Hello, filbert! I didn't know there is such a thing as matched pair sticks. The sticks i used were both Hynix 8GB; 1Rx16; PC4-3200AA with identical part numbers, so if completly identical sticks are not matched then i don't know what kind of sticks can be! Can you tell what exactly means matched pair RAM sticks and how can i find such?

Hello Ourab! I'm back and if you have any solutions to my issue i will be very happy!

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@Jordanbg90 wrote:

Hello, filbert! I didn't know there is such a thing as matched pair sticks. The sticks i used were both Hynix 8GB; 1Rx16; PC4-3200AA with identical part numbers, so if completly identical sticks are not matched then i don't know what kind of sticks can be! Can you tell what exactly means matched pair RAM sticks and how can i find such?

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Matched pair means two identical RAM sticks: same brand, model, size, timings. Manufacturers package sticks as matched pairs so the buyer knows they are identical. Otherwise, it's easy to buy same brand and size but end up with different timings that can cause incompatibilities.

If yours are identical part numbers, then I would think that they are they same.

You did not answer my questions in my first post. The only way we can diagnose issues is if users provide detail. I need to know if a set of matched sticks worked in your laptop. Also need to know if your stick works in either RAM slot and if the new stick works in either RAM slot, and if both sticks work in another laptop (you said the "service" checked everything and it all works, but unclear what tests they did).

You need to try the old stick in each RAM slot, see if it works in each. You need to try the new stick in each RAM slot, see if it works in each. That helps to narrow down whether there is an issue with one stick or one slot or whether it's simply two sticks not working together.

If you are installing the RAM yourself, be scrupulous about static avoidance. Whenever touching components or working inside a computer, wear a grounded wrist strap, also called anti-static wrist strap, ESD wrist strap, or ground bracelet. It's a cheap and sensible precaution. Rest the laptop on an anti-static mat or at least a reasonable alternative such as corrugated cardboard. 

Well i went first to the authorized service because my laptop is still in warranty. But they only had a few brands of RAM sticks wich they tested first in combination with the original and then in combination of two different sticks. The sticks didn't work in combination with the original. They said that probably the problem is that the original needs the same stick to work in pair. But they didn't had the same stick and said that it will take some time to find it. So i searched and found the same stick with the same specifications and the same part number and tried to install it myself(i know that i have to be carful i maintained my old laptop before so i know what i'm doing). I will explain what i did: i will name the original RAM stick - RAM 1. And the identical RAM stick which i bought  - RAM 2. I will also name RAM modules as A & B. So i tested seprately RAM 1 on both Module A and Module B - it worked. I also tested RAM 2 on both Module A and Module B - also worked fine. But when i install both RAM sticks(no matter which sticks goes in one of the modules) the laptop's keyboard lights up, the power led flashes but the screen remains black - the laptop doesn't boot, even the bios can not start.

I will check the timing of the sticks as you suggested. And write again when i have the results.

Good, let me know when you've checked that.

Also, it's worth trying a reset:

1. Disconnect the AC adapter.
2. Disconnect the battery.
3. Press and hold the power button for 30 seconds to discharge any residual electricity.
4. Reconnect the AC adapter
5. Boot the laptop into BIOS, to see if RAM is recognized.

The first three steps should have been done each time prior to installing, removing, switching the RAM, in addition to wearing an ESD strap. You may have done all that, but as you didn't mention it I thought I should add it.

1. Disconnect the AC adapter.
2. Disconnect the battery.
3. Press and hold the power button for 30 seconds to discharge any residual electricity.
4. Reconnect the AC adapter
5. Boot the laptop into BIOS, to see if RAM is recognized.

The first three steps should have been done each time prior to installing, removing, switching the RAM, in addition to wearing an ESD strap. 

If that still doesn't work, do the first three steps again, followed by removing the CMOS battery. Leave the CMOS battery out for ten minutes or so prior to replacing it.

Re. CMOS battery: Yes, you're right, the Service Manual does not show a CMOS battery. Several modern Dell models now draw CMOS power from the main battery, so your model must be one of those. In that case, follow that last set of steps that I gave you, but leave the battery disconnected for a while. You could also reset BIOS to factory defaults, though I don't know if that would help.

Re. BIOS update: Don't update it via SupportAssist or selecting Run from the drivers download site. Download the BIOS update file to your computer, saved on your primary drive. Then, with no peripherals connected and no other apps running, launch the file to update your BIOS. If that fails, you could update it from a bootable flash drive.

Well, i don't have CMOS battery! There is none on the motherboard. If you don't believe me you can check in the manual. I also checked visualy but still - no such kind of thing.

This is the first time a bought something from Dell and i'm really disapointed! First i had a problem with the battery - it stopped charging after 5 months! Now this.

Also i tried to update the BIOS and see if my problem with the RAM will be fixed but the BIOS can't update - the update finishes successfully but when i enter the BIOS the vesrion is still the old one!

My general conclusion - never again i will buy product of Dell!

Hello filbert! I've done everything you've said - i disconnected the main battery, drained the electricity in the system by holding the power button for 30 seconds, waited 10 minutes before i reconnected the battery, installed the 2nd RAM stick and powered the laptop. The result was the same - the issue remains.

I also tried to update the bios in every possible way - through the supportassist, the way you told me from the .exe i downloaded from dell website, also with usb. I also tried with .rcv file but still no success! I attached a picture from the failed installation through the uefi interactive shell with .rcv file.

I gues i have a major problem with my motherboard, which is very deissapointing having the laptop less than a year! I will try to return it and have my money back. But i don't believe i will succeed.

Thank you for all your help! I really appreciate it!

I am in the UK and have a Dell Inspiron 14 3481 (Reg. P89g) Laptop that came supplied with a single 4GB RAM stick. I bought two identical 4GB RAM sticks so I could upgrade this to an 8GB RAM machine. But the machine would not boot with the 2 sticks inserted (the light next to the power input would flash 4 white lights followed by 2 orange lights, indicating a RAM issue). Each stick individually worked fine in either slot.

After much searching (including on this forum) I found most people were putting it down to a failed motherboard issue. This was not an option for me because my machine was out of warranty, BUT THEN I found a Reddit thread where someone loosened the screws on the CPU and it solved the problem. So I loosened the screws on the CPU several turns AND IT WORKED !!!

I hope this helps someone else as it's helped me. What's concerning is that the Reddit thread was from 2015 and my machine is only 3 years old. So have DELL still not discovered they are, by default, overtightening the screws on their motherboards?