Dell Latitude 7410 dead and amber light as long power button is pressed.

[Zen Master]

I'm experiencing a similar problem with two Precision 7450s. Clearing the CMOS works for about two days, then the problem returns. Sometimes, removing and reassembling the motherboard allows it to power on, but not for more than two days. I haven't been able to pinpoint the problem yet, and I've also tried building a different BIOS. Has anyone found a solution?

[Andreasbest]

Have you solved the problem yet? Because I’m having the same issue as you. I reflashed the BIOS using the CH341A and now I’m getting an orange light when powering on, even when I flash back the previous backup

No, i never managed to solve it. Have no time to check more. All i know is that this behavior suggests power failure, meaning a SMD got broken during the BIOS process. Check visually the area around bios chip with microscope for any damage.

[conghuyms]

Left it on charge all night, no response.
On morning i had the same behavior.
DO you have any ideas or proceed in MB replacement?

Have you solved the problem yet? Because I’m having the same issue as you. I reflashed the BIOS using the CH341A and now I’m getting an orange light when powering on, even when I flash back the previous backup

[Andreasbest]

bump

[Andreasbest]

1v on PJP3
0v on PJP2 and PJP3

[Andreasbest]

The CPU happens to be right next to the BIOS chip. Have you checked if they are getting powered?

Finally managed to get some time on the bench with this motherboard. Thank you for replying.
Where do you want to measure?
Meanwhile i have 5v on PL701, PL101 and only 1v on PL301.
All other coils are 0v

Schematic -> https://www.badcaps.net/forum/troubl...67#post3170367

[davidebeatrici]

The CPU happens to be right next to the BIOS chip. Have you checked if they are getting powered?

[Andreasbest]

Unfortunately in my case everything looks intact.
The resistor is present and 22Ω

[hopkok]

I removed the heat sink and these was a capacitor which got blown away from near to Bios chip, i soldered it back looking at old pictures to confirm where it should be. Now the laptop is booting fine.

I was expecting that...

[Sephir0th]

Compatible schematics was shared with Post #2 on Page 1. It is a 22 Ohms resistor.

[vidvansh]

Black color capacitor got blown away from here which was stuck under the heat sink. I soldered it back and it worked.
Can anyone help me identify what part it is called so that i can order some as i have one dell latitude 5400 where 1-2 capacitors are blown while removing bios chip and i cannot find them on the motherboard.

[Andreasbest]

I removed the heat sink and these was a capacitor which got blown away from near to Bios chip, i soldered it back looking at old pictures to confirm where it should be. Now the laptop is booting fine.

Can you please point the blown cap location please?

[vidvansh]

I removed the heat sink and these was a capacitor which got blown away from near to Bios chip, i soldered it back looking at old pictures to confirm where it should be. Now the laptop is booting fine.

[hopkok]

Hi, remove heatsink, clean mobo with IPA and post picture of Bios area. How much heat did you use? Any short under wifi module, its close to bios chip.

[Andreasbest]

vidvansh has tried any possible way involving BIOS, like I did.
Problem is not on BIOS but on the rest motherboard, there is a high chance to have corrupted EC.

[vidvansh]

I flashed the chip with original dump and soldered it on the motherboard. no output. same issue of no activity and amber light when power button pressed.
I set down bios chip 2-3 times to confirm it is making contact with the board. Is there anything else i need to try.

[rddube]

I am having the same issue with my laptops. I tried 2 laptops which were bio locked. I de-solder the bios chip on both, flashed them and then soldered them back. After that both the laptop are not turning ON, no activity.Amber light turns On when pressing power button. Can not figure out what could be the issue. On 1 laptop which is dell latitude 5400 i can see that i am missing a resistor near the bios chip. Don't know what to do next. On 2nd laptop which is 7410, i cannot see any missing part. Any guide on what can i try to fix those laptops.

Post some nice clear photos of the areas you worked on giving a good perspective around the bios chip and we'll try to help. Did you try to reflash the original and see what happens?

[Andreasbest]

I will check again the area around bios chip, in case Ii damaged something.
Meanwhile I suspect that EC is corrupt.

[vidvansh]

I am having the same issue with my laptops. I tried 2 laptops which were bio locked. I de-solder the bios chip on both, flashed them and then soldered them back. After that both the laptop are not turning ON, no activity.Amber light turns On when pressing power button. Can not figure out what could be the issue. On 1 laptop which is dell latitude 5400 i can see that i am missing a resistor near the bios chip. Don't know what to do next. On 2nd laptop which is 7410, i cannot see any missing part. Any guide on what can i try to fix those laptops.

[rddube]

My friend listen, i tried before to explain it. 7310 and 7410 have exactly the same motherboard, i have tried all combinations of flashing, no luck. Dell Support confirm 7310 and 7410 have the same BIOS.
Problem is on power supply rails but i still haven't managed to get some free time and research for it.
I'll start with 3v and 5v measurements, probably after Easter and update.
I really hope we manage to solve it, lots of Dell users suffer from this issue.

Ok, well if you are convinced you have the right Bios, then the only other thing is that you have a hardware problem. "so i replaced from the fully working 7310 the bios chip UC5 and two other winbonds UT2 and UT9 but still the same behavior." means you used hot air I suppose - might have inadvertently unsoldered a resistance, capacitor, or something in the process. Check around those chips to see if you might have something that is misplaced. If you need help, post some clear and close photos of the areas you worked on. How would you rate your level of skill in using hot air ?