It appears that this model has a battery pack attached to the back of the display panel. So disconnect its cable from the motherboard and then press/hold power button for ~30 sec. Then reconnect the battery and see if it will boot properly now.
If the display works correctly when connecting a Wii via the HDMI-In port, I guess it's possible the CPU itself has failed, or possibly the hard drive or its interposer board...
Only you can decide how much time and $ to put into fixing this PC yourself. You can always contact Dell's Out-of-Warranty Repair Service to get an estimated price for them to fix it.
Ron, I opened the box and did the CMOS battery power cycle this afternoon on the replacement board.
No change. Once reconnected, I'd get "Waiting..." followed by a black screen. Holding down the button for 30 seconds or more just cycles the process (Waiting...black screen. Waiting...black screen).
The model I have has the battery pack on the back of the panel, but the replacement board does not have it. Both are DAQF 2AMB6A0 Rev A, but the original is P/N #31QF2MB00C0 A3B (built 10/17/2014), and the replacement is a 09/17/2014 board that's P/N #31QF2MB0010 A3E.
Either way, the first thing I did in this whole process was to disconnect the battery from the first motherboard, so we can safely rule that out.
I was able to pull data from the hard drive by putting it in a drive dock (I'm doing this for a friend), and while I didn't check SMART on the drive, I didn't encounter anything that would indicate a problem with said drive. Would this model fail to POST entirely without a drive? I tried attaching a Dell external USB DVD drive, which did not detect, boot, or show any signs of recognizing the OEM Windows disc that was in it.
My guess is that the CPU on both boards have overheated and destroyed themselves. The heatsink on them is amusingly small.
Not really going to bother with it at this point. Have been able to get the data off, so that's a win, and I get the spoils (the rest of the computer. Here we go, eBay).
it dead, 100% dead, no sounds no screen data, no fans spin, no video /hdmi.
ever take off the back? see what is there, not much really.
first off is the power pack, is the voltage correct at the jack of the mobo, at power pack input?
is the power jack broke, look carfully, wiggle it gently see if POWER wakes up?
if no the pack is bad or there is a short (on or things connected to the mobo. )
so remove things, disconnect the HDD, does power turn on now,
is the fan blocked in lint? try to get the fan going, is one tactic. (the book mentions the fan but never shows it)
for sure it's a power problem. (but shorts can happen on any bus not just power)
we reduce the them to a minimum and get the fan to run then next BIOS working on the screen.
even run 1 stick of DDR ram, in slot 0
the try other 1 stick at a time., oops has only 1 slot... (not dual channel ,wow crude)
remove the wifi card, I t too could short.
The word fan may be wrong, the mobo, is removed flipped over and the finned heatsink is there. with odd fins
but no fan there, so must be a heat spreader, or some hidden fan I can not find even watching full video take down. I'd never own a AIO so , must say , good luck,
if the BIOS stays dead, with PC stripped to MIN> the MOBO or power pack is bad , if the voltmeter shows PACK at spec DC voltage, then MOBO.
test the RTC coin cell for over 2.9vdc.? a $1 part, DIY made, ask.
I opened the back and proceeded to disconnect unnecessary equipment (speaker, etc) until I was left with the system board and the pigtail that connects to the PCB with the on/off switch. The LED board and ribbon cable remained as well.
There's no fan on this board. Small heatsink over the laptop-based integrated CPU. That's it. Zero dust stuck in it; looks new.
Got the same result. Disconnecting the CMOS battery (which tests OK for voltage; I also swapped it with an old ThinkPad's battery that I had here; it shared the same plug) also results in the same behavior, though upon reconnection, I was able to get the power light to stay lit for longer before it would turn off and then do it's second flash.
I want to say "system board" here, but it's very difficult to sat for sure when Dell has not covered these units in good detail at all. I'd really like to know if that single flash is indicative of anything.
When you swapped the battery, did you power off, unplug and press/hold power button for ~15 sec, and then press/hold power button for ~30 sec after removing the existing battery, and only then install a known good one?
I'm pretty familiar with the diagnostic lights from work; that's one of the reasons it stumped me.
I went through the usual power button cycle. No change.
The plot thickens though: I was able to source a replacement board from eBay. I installed it and bench tested it enough to see that the LCD was powering up (it's a PAIN to have both the power button connected to the rear panel AND have this thing open).
After verifying LCD functionality, I reconnected everything (but forgot to reset the CMOS as properly - might have an effect here; might have to pop everything open again), and attempted to boot. I'm getting either No Signal followed by a white screen, or No Signal, followed by nothing. OEM hard drive is installed. No Dell logo or any hints of a POST.
The maddening part is that I have successfully connected a Nintendo Wii U to the motherboard's HDMI In port, and it works fine. I dare say this should mean that I have all the board connectors seated correctly, and that there aren't any issues with the inverter.
Methinks I've come across yet another dead board; this one partially dead.
I’m having the same experience with this model. However with one interesting twist. If you continue to power on the unit, say around 20 times it will start and act completely normal. Boots into windows fine like nothing is wrong with it. But after a restart or shut down it goes back to the same behavior. CMOS corruption comes to mind maybe? I was going to try and flash the bios to see if that did anything. But I’m not sure if the procedure requires a reboot to update in batch, that would probably fail. How can any board be bad if it posts when it wants too? This is strange to say the least. Nothing worse than intermittent problems. If anyone has any ideas I would be so appreciated .
RoHe
10 Elder
•
45.2K Posts
1
May 8th, 2019 16:00
It appears that this model has a battery pack attached to the back of the display panel. So disconnect its cable from the motherboard and then press/hold power button for ~30 sec. Then reconnect the battery and see if it will boot properly now.
If the display works correctly when connecting a Wii via the HDMI-In port, I guess it's possible the CPU itself has failed, or possibly the hard drive or its interposer board...
Only you can decide how much time and $ to put into fixing this PC yourself. You can always contact Dell's Out-of-Warranty Repair Service to get an estimated price for them to fix it.
cudak888
5 Posts
0
May 9th, 2019 15:00
Ron, I opened the box and did the CMOS battery power cycle this afternoon on the replacement board.
No change. Once reconnected, I'd get "Waiting..." followed by a black screen. Holding down the button for 30 seconds or more just cycles the process (Waiting...black screen. Waiting...black screen).
The model I have has the battery pack on the back of the panel, but the replacement board does not have it. Both are DAQF 2AMB6A0 Rev A, but the original is P/N #31QF2MB00C0 A3B (built 10/17/2014), and the replacement is a 09/17/2014 board that's P/N #31QF2MB0010 A3E.
Either way, the first thing I did in this whole process was to disconnect the battery from the first motherboard, so we can safely rule that out.
I was able to pull data from the hard drive by putting it in a drive dock (I'm doing this for a friend), and while I didn't check SMART on the drive, I didn't encounter anything that would indicate a problem with said drive. Would this model fail to POST entirely without a drive? I tried attaching a Dell external USB DVD drive, which did not detect, boot, or show any signs of recognizing the OEM Windows disc that was in it.
My guess is that the CPU on both boards have overheated and destroyed themselves. The heatsink on them is amusingly small.
Not really going to bother with it at this point. Have been able to get the data off, so that's a win, and I get the spoils (the rest of the computer. Here we go, eBay).
-Kurt
savvy2
3 Apprentice
•
2.5K Posts
0
May 2nd, 2019 07:00
it dead, 100% dead, no sounds no screen data, no fans spin, no video /hdmi.
ever take off the back? see what is there, not much really.
first off is the power pack, is the voltage correct at the jack of the mobo, at power pack input?
is the power jack broke, look carfully, wiggle it gently see if POWER wakes up?
if no the pack is bad or there is a short (on or things connected to the mobo. )
so remove things, disconnect the HDD, does power turn on now,
is the fan blocked in lint? try to get the fan going, is one tactic. (the book mentions the fan but never shows it)
for sure it's a power problem. (but shorts can happen on any bus not just power)
we reduce the them to a minimum and get the fan to run then next BIOS working on the screen.
even run 1 stick of DDR ram, in slot 0
the try other 1 stick at a time., oops has only 1 slot... (not dual channel ,wow crude)
remove the wifi card, I t too could short.
The word fan may be wrong, the mobo, is removed flipped over and the finned heatsink is there. with odd fins
but no fan there, so must be a heat spreader, or some hidden fan I can not find even watching full video take down. I'd never own a AIO so , must say , good luck,
if the BIOS stays dead, with PC stripped to MIN> the MOBO or power pack is bad , if the voltmeter shows PACK at spec DC voltage, then MOBO.
test the RTC coin cell for over 2.9vdc.? a $1 part, DIY made, ask.
even unplug LCD and see if fan wakes up.
cudak888
5 Posts
0
May 4th, 2019 22:00
On the second power supply. Same result.
I opened the back and proceeded to disconnect unnecessary equipment (speaker, etc) until I was left with the system board and the pigtail that connects to the PCB with the on/off switch. The LED board and ribbon cable remained as well.
There's no fan on this board. Small heatsink over the laptop-based integrated CPU. That's it. Zero dust stuck in it; looks new.
Got the same result. Disconnecting the CMOS battery (which tests OK for voltage; I also swapped it with an old ThinkPad's battery that I had here; it shared the same plug) also results in the same behavior, though upon reconnection, I was able to get the power light to stay lit for longer before it would turn off and then do it's second flash.
I want to say "system board" here, but it's very difficult to sat for sure when Dell has not covered these units in good detail at all. I'd really like to know if that single flash is indicative of anything.
-Kurt
RoHe
10 Elder
•
45.2K Posts
1
May 6th, 2019 18:00
It's odd the power button blinks white once (and then once more) because all the listed blink codes are for an amber power button.
The power button will blink white continuously if it's in a low power state, either S1 or S3 but that doesn't indicate a fault condition.
Diagnostic LEDs for the Inspiron Desktop series (2015 to Present) eg, for Inspiron 660's, 3252's to 3655's and 20 to 24 AIO's.
When you swapped the battery, did you power off, unplug and press/hold power button for ~15 sec, and then press/hold power button for ~30 sec after removing the existing battery, and only then install a known good one?
cudak888
5 Posts
0
May 8th, 2019 13:00
I'm pretty familiar with the diagnostic lights from work; that's one of the reasons it stumped me.
I went through the usual power button cycle. No change.
The plot thickens though: I was able to source a replacement board from eBay. I installed it and bench tested it enough to see that the LCD was powering up (it's a PAIN to have both the power button connected to the rear panel AND have this thing open).
After verifying LCD functionality, I reconnected everything (but forgot to reset the CMOS as properly - might have an effect here; might have to pop everything open again), and attempted to boot. I'm getting either No Signal followed by a white screen, or No Signal, followed by nothing. OEM hard drive is installed. No Dell logo or any hints of a POST.
The maddening part is that I have successfully connected a Nintendo Wii U to the motherboard's HDMI In port, and it works fine. I dare say this should mean that I have all the board connectors seated correctly, and that there aren't any issues with the inverter.
Methinks I've come across yet another dead board; this one partially dead.
-Kurt
Markinpuff
2 Posts
1
August 11th, 2019 08:00
I’m having the same experience with this model. However with one interesting twist. If you continue to power on the unit, say around 20 times it will start and act completely normal. Boots into windows fine like nothing is wrong with it. But after a restart or shut down it goes back to the same behavior. CMOS corruption comes to mind maybe? I was going to try and flash the bios to see if that did anything. But I’m not sure if the procedure requires a reboot to update in batch, that would probably fail. How can any board be bad if it posts when it wants too? This is strange to say the least. Nothing worse than intermittent problems. If anyone has any ideas I would be so appreciated .