DELL T3500 PB12 issue ( not solved )

[davidcarey]

My last post seems to have died . Does anyone have a T3500 at home /work with a PB12 issue ? I am interested in finding out if my solution ( you get a working computer in 1 minute ) is repeatable in other units . There are probably many components that could cause the PB12 , BUT so far as I can tell NO-ONE has identified exactly what broke and No one has recovered from the issue .

 

[LTC8K6]

Should probably just continue in the original thread.
https://forums.anandtech.com/threads/dell-t3500-will-not-start-solved.2546650/

 

[Ketchup]

I have an older Dell that runs fine until you put it to sleep, so I just disabled that functionality (it's old after all, just something for the kids to play on). My suspicion is that it, and possibly yours, needs a new CMOS battery, but it's an AIO, and works fine otherwise, so I am in no rush.

 

[davidcarey]

Ketchup I replaced the CMOS battery .
There must be thousands , if not hundreds of thousands of T3500s out there , and sadly most ( all ? unless anyone else has recovered ) getting a one way trip to the landfill after a "terminal" PB12 error . I thought mine was junked ( everyone said so ) , but here I am , still using it . I can see that i will have to try and buy the junked one that the dealer had ( when he replaced it with this one - that also had a PB12 error ) prove a point .

 

[Ketchup]

You still weren't clear in your other thread what you did to fix it (in fact, your last post indicated that you thought you did, but in fact did not). And most of these that are in a landfill are probably there because they have been retired, as this model number goes back at least 9 years.

 

[davidcarey]

Ketchup The computer , after a cold shut down , still shows 1 + 2 , BUT I can get it past that and working in a minute . Is it fixed ? Well not technically , as I do not know exactly what component on the MB is at fault , hence the request for more information . It MAY be that what I am doing is only specific to MY PB 12 issue OR it may be that others can resurrect boards . Since I first got it working , now about seven times - so no fluke , I have honed it down to a very simple operation .

 

[XavierMace]

You've been asked multiple times what your "fix" is. Are you going to share at some point?

 

[davidcarey]

These damned overnight power cuts are annoying me , computer has shut off again and will not start ( at the moment , anyway ) . When It is working for some time it can be shut down and restarted , put to sleep overnight and starts up fine . Can anyone suggest why this is ? There MUST be a solution to this , maybe a solution to ALL those MBs consigned to the scrap heap .

 

[davidcarey]

Machine is working fine . After a really bad day yesterday when we had at least 9 power outages in the morning ( and the UPS is not holding ) , I gave up and went out for 2 hrs and the machine booted up first time on return ( no PB12 ) - technically that would be a "cold" start as the temp in house is 80-85 F. constantly . I am still doggedly searching for more info on what can cause a PB12 and if anyone else recovered use after the PB12 . If I had been anyone else apart from me , I would have ordered a replacement MB long before now ( and wasted my money ) .
I would feel like a fool if I had taken advice and bought a SH replacement for $90 ( incl shipping ) with a mere 30 days warranty and someone else showed me his working T3500 after a PB12 . After all I only paid $150 for the computer ( from a dealer ) with 6 GB and a W3565 ,

 

[dave_the_nerd]

You've been fighting this for a lot longer than that.

https://forums.anandtech.com/threads/dell-precision-t3500-will-not-start.2523768/

Look: PB12 means one of two things - bad component on the motherboard (just because it's bad doesn't mean the computer won't work at all, just means it won't work sometimes - capacitors and VRMs can sort-of-half-fail and work intermittently for a long time before they go for good) or a shorted peripheral/component like a hard drive or something.

It's an electrical problem.

Resetting your BIOS won't make it go away. Either replace the motherboard, or replace the PSU, or get a soldering iron and replace the caps and VRM. (Even if they don't look bad/swollen/leaky, caps can still be bad.)

 

[davidcarey]

dave_the_nerd Thanks for replying . The previous post was regarding the first PB12 . I had the machine replaced under the ,very generous 3 month warranty , though I did not spend as much time on that one as this present one ( very possibly now , if presented with the same machine /MB , I could maybe get it working again ) . Regarding you comment on replacing caps and VRMs , I am pretty sure VRM replacement is not possible on this board unless you have experience of having done so . The diagnostic lights rule out PSU failure .

 

[davidcarey]

Still no bright ideas about exactly what the problem is ?