VLC Fan Service

Tuesday 4 January 2011, 09:04 PM Posted by urbancamo

I've spent 30 minutes this evening servicing the fans on the VAXstation 4000/VLC which were quite noisy. Brushless fans often get noisy due to the factory-installed bearing oil slowly drying out over thousands of hours of use. A new drop of oil can breath considerable more life out of noisy fan, as well as making the computer substantially quieter. Larger images are available by clicking on the inline images.

I removed the power supply from the VAXstation. It required a star-bit head, which I didn't previously have. The screws were in tight enough that there was going to be no bodging it open with a different tool. The power supply is installed with the circuit board face down. Two screws need to be removed, the power connector disconnected and the power supply slid out of locating lugs and then pulled out.

Power Supply Removed

This machine hasn't been run a great deal since it came into my hands. Although I didn't take the power supply out when I got the box, I did give the motherboard and the internals a clean with trusty brush and air duster. Hence very little debris inside the case.

Not much debris

Here's the toolkit I used:

  • Tape measure
  • Stanley knife
  • Pliers
  • Multi-head screwdriver and tweezers
  • Paint brush
  • Three in one oil

Note that the hair bobble and lipgloss are entirely optional.


Here are the fans in the power supply. They are housed in rubber mountings.

Two fans

The PCB was remarkably clean considering I'd not opened the power supply, only air dusted it. I'm not wearing a dressing gown, honest.

Clean PCB

The humble paint brush is an excellent tool for getting rid of dust.

Dusting the fans

It's always worth taking a close look at the top of the electrolytic capacitors (those marked with polarity) for leakage or bulging tops. No problems here

Check the capacitors

Measure the fans in case renovation is unsuccessful and replacements are required

Measure the fans

Carefully remove the labels. Replacing the original labels may be possible if they contain a plastic mix. No such luck in this case - the labels were thin paper.

Remove labels from fans

Take the opportunity to either photograph the labels before removal or write down the details to aid in finding replacements.

Make a note of the fan type

With the label removed you can clearly see the central bearing.

Label removed

A single drop of oil on the centre of the bearing will be drawn into the fan. Turn the fan manually a few times to gently encourage the oil into the bearing.

Oil the fan bearing

If you need to replace the labels find something approximately the same size

Find something the same size as label

This is a 15mm radiator plug that I found lying around in the kitchen.

15mm radiator plug

Mark out labels as required.

Mark out two labels

The new labels don't need to be terribly accurate.

New labels don't have to be that accurate

Cut out the labels.

Cut out labels

Using a paper glue and a paint brush carefully pain glue around the outside of the bearing, ensuring you don't get glue on the bearing itself.

Paint glue onto fan body

Carefully position the label and then paint additional glue around the outside of the label to seal the edge.

Position label and glue round edges

Do the same thing with the second fan.

Same with the second fan

New labels glued in place - servicing complete!

New labels in place

Slide the power supply back into place.

Slide power supply back in place

Ensure all tabs are located correctly in their slots.

Tabs located next to the PCB

Reconnect the power cable.

Reconnect power cable

Ensure the power cable is firmly reconnected.

Ensure power cable firmly reconnected

Replace the two screws securing the power supply.

Replace two screws securing power supply

I powered up the VLC and there was a noticable reduction in noise from the fans. However, having had to remove all the cables a previous problem reared its' ugly head - the video cable on these VAXstations is terminated in a connector called a 3W3 - basically three mini-phono connectors in a D-type housing.

3w3 connector

The cable contains the female end, with the pins contained in the connector on the motherboard. Well that's how it should be. Unfortunately one of the pins has dislodged (the solder joint having given up the ghost) and was stuck in the end of the cable. You can just about see this in the photo above - the left hand (red) pin is missing.

This had happened before! I have two choices. I can attempt to resolder the connector, which given it is in the housing I think is pretty much a non-starter. I have some video cards that contain a similar connector one of which (if I've still got it) is probably broken, so if I'm feeling brave I may unsolder the existing connector and replace it.

3w3 connector on the motherboard

That's one for another day however!