0

I have an out-of-warranty Dell Latitude E7250 which sometimes shuts down suddenly when on battery:

  • only when being physically handled/moved
  • battery installed, not empty
  • has happened while idling, so no issue with heat and unlikely to be software issue
  • no warning or error, just instantly off
  • no problems powering back on

The power/battery indicator also has blinked battery error codes when the laptop has been handled similarly with the AC adapter plugged in.

Other notes:

  • BIOS reports the battery is in excellent condition
  • the AC adapter is the original Dell unit
  • BIOS diagnostics have reported no problems

The BIOS event log sometimes registers a not-very-descriptive error after these shutdowns.

I ran memory tests when I got it over a year ago, with no errors reported. The laptop has been reliable in general, but I'm afraid to handle or move it when doing anything important. It is very inconvenient to experience shutdowns even when data loss is not a worry.

My best guess is that it is due to some contact issue, since it happens when handling the laptop in a way that presses on the exposed battery pack on the bottom front area.

I don't notice anything wrong with the laptop's battery contacts, and the battery pack does not appear damaged or bloated.

enter image description here

Is there any known issue with the E7250 or its battery pack? Any ideas how to troubleshoot and solve this?

Improve this question
11
  • Another answer (has happened to me a while back) is a small break in a circuit board trace on the motherboard. This will manifest itself in most / all of the symptoms above.
    – anon
    Commented Jan 21, 2020 at 2:31
  • @John How difficult was it to spot such a break in a trace? I'm not sure I want to completely disassemble the laptop at the moment, but if/when I do, I'll keep this possibility in mind and try to inspect carefully.
    – adatum
    Commented Jan 21, 2020 at 2:38
  • My laptop back then was in warranty, and the technician said he was able to flex the board and cause the issue. The board was sent back and I got a replacement board. It would be very difficult to spot the break especially in a two or three layer board. You would need special circuit testing equipment to test the top or bottom surfaces
    – anon
    Commented Jan 21, 2020 at 2:40
  • @John Oh, I see. Makes sense. One problem is that I have not been able to reproduce the shutdowns at will, despite the patterns I've observed. The Dell warranty is expired so I can't get service there without paying a significant fraction of its current value. I bought it refurbished and while I just realized the reseller's warranty may still be in effect, I'm not sure what can be done if I cannot demonstrate the problem.
    – adatum
    Commented Jan 21, 2020 at 3:15
  • 1
    @barlop The laptop has only a mSATA SSD, and no HDD. Besides, if the disk lost connection, wouldn't that cause IO errors or data corruption, and not shut down the whole laptop?
    – adatum
    Commented Jun 30, 2020 at 2:53

3 Answers 3

Reset to default
0

So i had this issue, the diagnostics did not give me much information. The fan did not fail, however i could see that CPU temp, was very close to the highest temp it should be. To further explain, there is a table, that will say

Temperatures

Current temp 70
Highest Temp 74
Lowest Temp 48

I stripped the laptop down and removed the fan and heat sink, separating the heat sink from the processor was very tough, as the thermal past had hardened like cement. New thermal paste has been applied. I have now resembled the laptop and the temperature has lowered to 65. It has been more than 4 hours and the machine has not turned off by itself.

I hope this helps.

Improve this answer
4
  • This only applies if the CPU temp is very high
    – barlop
    Commented Jun 30, 2020 at 1:01
  • You say "the diagnostics did not give me much information" <-- Not true. You yourself said the CPU temp was sky high
    – barlop
    Commented Jun 30, 2020 at 1:02
  • Also, he says "When Handled". CPU Temp has nothing to do with "When Handled"
    – barlop
    Commented Jun 30, 2020 at 1:05
  • Thanks for the suggestions, but 1) my CPU temps are not high, 2) the shutdowns have happened typically at idle or low usage (when temps are low 40C-50C), 3) the shutdowns happen only when the laptop is physically handled. So, I don't think my issue is due to temps.
    – adatum
    Commented Jun 30, 2020 at 2:47
0

The problem seems to have been a bizarre case of dirty contacts. I have not had issues since cleaning the contact surfaces on the battery and laptop with alcohol, a cotton swab, and a small screwdriver.

This was prompted by very strange behavior lately, with the CPU stuck at less than the minimum 400 MHz frequency while on battery without running hot/throttling. Then, the laptop's onboard diagnostic (accessed via FN key while booting) failed to detect the battery, even though it was installed and running on battery... Plus the laptop started blinking an error code indicating no battery found.

I thought about replacing the battery, but the BIOS shows the battery is in "excellent" health. So I first thought to clean the contacts, and noticed at least one battery contact had a small clear solid clump of debris, like varnish or glue, which came off. Since then, the CPU is back to full speed, there are no more diagnostic failures or blinking error codes, and as a nice bonus, troubleshooting those issues may have revealed the root of the sudden shutdown problem as well.

I can't be certain, but so far so good.

Improve this answer
-1

You could try to remove the ram memory and reinstall. Sometimes this will fix the problem. Otherwise you most likely have a more serious problem with the system board, possibly a weak solder joint for the battery connector or other problems.

Improve this answer
1
  • I have never seen faulty RAM cause an immediate shutdown, please provide a link to substantiate that claim
    – barlop
    Commented Jun 30, 2020 at 1:02

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .