Dell optiplex GX620 Board problem

[bluestone]

I am a tech from Africa and my supplier just brought in some second-hand computers from uk. But there seems to be a common problem with all the dell optiplex GX620 and Dimension 9150, the problem is the computer will not power on, when you press the power button u only see a blinking power led and fan does not spin no drive activity but when you open and disconnect the processor's 12v power, then the board will power on with fan working and drives spinning but orange power led and no display. If anyone has ever come close to such a problem i will want them to help me out.

[selldoor]

Re: Dell optiplex GX620 Board problem

Hi - I am not familiar with these machines but there are many posts on this forum. Have you tried the search facility?
One such thread is here https://www.badcaps.net/forum/showth...t=gx620&page=4. I dont actually know what you mean by "disconnect the processor's 12v power".
Perhaps pictures of the board and an indication of what you are disconnecting would help.
Having looked at the your other posts I guess you will have checked for
bad caps and replaced any leaking ones, however many others could just be dried out. If leaking is considerable it may cause a short on the motherboard - clean all of it off. The problem may be that the power supply is faulty and whilst supplying 12 volts initially it cant support running the whole thing. Try it without the hard drive/cd attached. It does seem odd that all your machines are affected - how many are we talking about?
Have you one that works that you can swap parts out of to try and
see if it is a power supply or motherboard problem.

[bluestone]

Re: Dell optiplex GX620 Board problem

I have tried a lot of options, but when i take out a working board and cross check with the dead one i realize this; all the small brown capacitors on the board read ohms and i thought there was a short on any of them but after taking them off they read normal, i have not seen this before and i don't know what to do. i have the same problem with dell dimension 1950 too.

[selldoor]

Re: Dell optiplex GX620 Board problem

Ok - Get a motherboard and power supply that work properly.
Get a motherboard that doesnt work and post good clear photos using "manage attachments" which is In "Go Advanced" under "Quick reply".Front and back and close ups of any sockets and any bits which suspect are bad. We need to be able to read the part numbers on the board.

Put the faulty board in and give us a commentary on what happens - lights sounds
fans- does processor get warm etc

By "Small Brown capacitors "do you mean ceramic ones? - I dont think they often fail shorted. What are you checking them with- again pictures would help and board part descriptions.