Dell T3500 will not start (Solved)

[davidcarey]

Hello , I have a PB12 problem with my Dell T3500 . Shows 1 + 2 lights . This generally means a motherboard issue . The oddity here is that this problem arose some time ago and then disappeared , a few weeks ago the front two fans started running at high speed constantly up until yesterday when i decided to shut down instead of sleep/hibernate . I have cleared BIOS and reseated the graphics card / memory ( also tried 3 ram sticks / 6 ram and switched them ) . During the startup attempt all fans run , front 2 , rear 2 and Graphics card . Now if something on the motherboard broke ( usual general consensus is that a PB12 means the MB is dead ) , why would it work up until now ?
This is the second M/B ( the first was replaced by the vendor - well actually swapped the whole computer ) that I have had this problem with . Hoping someone has some insights into this problem as a replacement is not available locally , and the shipping expensive .

 

[daveybrat]

I just repaired a Dell Precision T3500 a week ago. Same symptoms and it ended up being a bad motherboard. I ordered a good tested one off Ebay and replaced it. Worked just fine afterwards. The board cost around $40ish.

 

[davidcarey]

I just repaired a Dell Precision T3500 a week ago. Same symptoms and it ended up being a bad motherboard. I ordered a good tested one off Ebay and replaced it. Worked just fine afterwards. The board cost around $40ish.

Thanks for the reply . THIS board was a "good tested" ( replacement for the previous one that had the same issue ) one that was working fine for many months . The board may cost 40ish but the shipping charges will at LEAST double that . Look at the shipping cost of a new board with warranty !
Why would I previously have a PB12 issue ( tried many times and resigned to a junk throw away computer ), then suddenly repaired itself and continued for many weeks ? Can anyone explain what has actually ceased to work and why ? When I press the power button the 3 and 4 lights actually flash momentarily .
The Dell case is a marvel and made to a high standard , the power supply suitable for long use , But I am more that a little miffed at not one , but two boards failing for exactly the same reason within a relatively short time .

 

[jana519]

It's possible (not for sure) you may have a faulty PSU which is the cause of your problems. I would at least try switching in a different PSU to see if that helps before you assign the motherboard to the garbage bin.

 

[davidcarey]

EUREKA !! I have recovered from this PB12 error ! I am now sending this post from the same computer that everyone condemned as broken . Sorry for this blatant act of crowing but I have not heard from anyone who has done this . Am I alone in this ?
daveybrat I hope you did not throw out your old ( considered Useless ) motherboard ?
I must have tried hundreds of times to get this thing working , press the power button and 1 + 2 lights flash and the power shuts off - Then I see something , and figure out the back-door .

 

[XavierMace]

EUREKA !! I have recovered from this PB12 error ! I am now sending this post from the same computer that everyone condemned as broken . Sorry for this blatant act of crowing but I have not heard from anyone who has done this . Am I alone in this ?
daveybrat I hope you did not throw out your old ( considered Useless ) motherboard ?
I must have tried hundreds of times to get this thing working , press the power button and 1 + 2 lights flash and the power shuts off - Then I see something , and figure out the back-door .

Are you going to share your solution?

 

[davidcarey]

OK . After the session ended , I stupidly put the computer into hibernate ( which has been very slow to re-start previously ) instead of sleep and it has reverted . Now the thing is If I have , not once but TWICE , been able to recover from what is generally accepted as a terminal problem then it cannot possibly be broken beyond hope . It would have to be said that I am persistent , and Desperate , so I probably spent more time than most would ( just how many times would YOU press buttons until you ordered a overpriced s/h replacement ? 10 ? 20 ? ) trying to get it to work .
Now , AT WILL , I can get the computer to flash not the 1 + 2 front panel lights , but the 3 + 4 , which is the normal starting sequence . The problem is that it then shuts down .
Any insights would be appeciated .
Has anyone else managed to get a T3500 working after a PB12 error ?
The fact that It has recovered twice ( 3 times , see following post ) is indicative that the problem is rectifiable .

 

[davidcarey]

OK . Now THIS is REALLY weird ! Last post I made from an Internet cafe , I get home and FIRST attempt I get it working again ! Now am sending from the T3500 .
Can anyone come close to an explanation ( apart from an act of God ) ?? I think I may contact the dealer who sold me the first T3500 ( " died " from the exact same problem ) and try and buy it back ( at a reduced price of course ) !

 

[XavierMace]

Recoverable is not the same as rectifiable.

 

[davidcarey]

XavierMace All information available to me online suggests that a PB12 is terminal ( as in cannot use ) I have no info on anyone who has gotten further than 1 + 2 , but I eagerly await further comments . I am interested in finding out more information , if others have managed the same and what exactly is the component at fault .
Recoverable - able to be regained or retrieved
Rectifiable - Able to be rectified; correctable; fixable.

 

[LTC8K6]

Dry/loose solder joints that occasionally make contact, but often don't.
That's my guess.

 

[jana519]

Are you going to share your solution?

No, that will be $3.99 PayPal.

 

[SKORPI0]

EUREKA !! I have recovered from this PB12 error ! ...........Then I see something , and figure out the back-door .

What did you see?

 

[davidcarey]

Back , again . Now after I get it working again ( Just done it for the 4th time ) I can put it into sleep mode and it will re-start , into shutdown and it will re-start ( but not the last time which was an overnight shutdown ) . Sounds like a heat issue . Now if only we can figure exactly which component .