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Hardware

Hardware : Dell GX620 SFF HTPC Bootup problem due to burned up capactiors

Posted on by Vishal Jain

I added a PCI Express Video card to my Dell GX620 Small Form Factor desktop system and connected it to my Television. One small thing that I completely missed out was the amount of heat that gets generated in such a small confined spot with no outlet for that hot air. And one day it refused to boot up. It will not go to POST. The power LED will come Green, fan on the processor will come on and then switch off. After 3-4 retries it will boot up and display “A Thermal Event has occurred“. But I did not pay attention to that. Silly me. After couple of days it started to take about 20 tries. That’s when I started to search around.

There were so many posts but no real answers. But there was a common lead badmouthing Dell and other PC manufacturers that for saving cost they have used cheap capacitors that burn up.  In my case that was certainly not true. The system had best that market has to offer (Rubycon capacitors) but it was me who managed to burn them off. I got the final on it when I stumbled upon BadCaps.net. A very good website with information on what exactly was going on. So I opened up the system, took out the hard-disk and right under it on the mother board were four capacitors (2200 µF, 6.3V, 10mm) that were popped. The heat from Video card fried the poor chaps as they were too close.

So I started to look around to buy capacitors at cheap. BadCaps.net has all of them and even the full kits made for particular system but shipping of 5$ was the killer. I found TheCapKing.com which also had similar kits and loose capacitors available but with free shipping. Got the capacitors from TheCapKing.com finally. Then instead of soldering the old capacitors back on the mother board, I relocated them to a cooler part of the system to avoid burning off again. I cut off an Ethernet cable, soldered the pairs to mother board and soldered the capacitors on the other end keeping the polarity correct.

Recipe to fix

Things we need:

  1. Right set of capacitors that burned off.
  2. Soldering iron. Solder, solder wick or solder vacuum to take off the old solder
  3. Wire if you want to relocate the capacitors to a cooler part of system. (Optional). I chose an Ethernet cable which has very good wire twists with colour coding.
  4. Stainless steel needle or soldering tool to clear the holes of solder.

Method

  1. Make sure that you have grounded yourself because that minor static could cause big damages to the internals.
  2. Open up the system.
  3. Disconnect all peripherals like hard-disk, dvd drive, power supply, memory, CPU cooling fan.
  4. There are screws at the back of case for power supply. Unscrew the power supply so it becomes easy to slide off the mother board.
  5. You must remove CPU cooling unit by removing the two screws that are located near the front side of the unit. Then the CPU cooling unit can be taken out leaving the second holding side still screwed on the motherboard. Take that second part of holder as well by unscrewing those two screws as well.
  6. Mother board has four screws. Take them off and slide the mother board off of chassis.
  7. Make a note of capacitors and their locations. You do not want to put in a different capacitor. Usually polarities are printed on the mother board, otherwise also make a note of that or better take a photograph before moving on removing the capacitors.
  8. With solder iron loosen up the bad capacitors one lead at a time. While you are loosening up the lead push the capacitor to the other lead to easily take it off.
  9. Clean the soldering spots by inserting the needle while soldering iron on other side. Do not force the needle otherwise you may damage the mother board.
  10. Now put on the new capacitors or solder on the wires and solder the capacitors to the wires.
  11. Once all done, put back the mother board in chassis, tighten the screws, followed by heat sync/CPU cooler, then memory, DVD drive, hard disk, power etc.
  12. Boot up and enjoy 🙂

So that was fixed. But next thing that may fry up is the hard-disk. Hopefully I will find a better cooling method soon.

, , ,
Vishal Jain

2 Comments

  1. My Dell GX620 SFF has a heat damaged HDD. As I write this I am trying to remove the CPU cooling fan in the front of the case to reverse it. Heat from the CPU will be blown out the front of the case instead of blowing back toward the HDD. I am planning to make a plastic replacement for the removable case door with an external mounted inward blowing fan to keep the heat from the MB finned heat sink from frying another HDD and the capacitors on the MB. I believe the air blown into the case will cool and force heat out of the case through the open areas on the rear. The improvised plastic case door can be replaced by the original door when transporting the unit. Any comments ?

    1. That is a good idea Mike. I was planning a similar approach by using the laptop chiller pad which has two fans. Its length will match about one side of the box and leftover open areas can be covered by plastic or some other material. That will force air into the box. Reversed CPU fan and outlets at the back will let the hot air out. The fan (as you are planning) or the laptop chiller pad can be powered by the USB ports at the back of system. If you are planning to use fan, buy a cheap USB cable from dollar shop and cut it. Strip its power cables (red and black) and connect to the fan connector and you will have a working fan available. Best would be to cut a hole in the original door and add a fan there.

      While removing CPU take extra caution with the thermal paste. I screwed up mine and now after running the system for sometime, if I shut it down, it would not power up until CPU cools down. I think I need to buy some good quality thermal paste.

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