Pump Troubleshooting Possible RMA.

Skeng · 13 Aug 2010 at 03:14

Well one of my Swiftech MCP350 pumps has for some reason decided to stop working on me. The weird part is I have no idea what is wrong with it.

I've spent a few hours doing different test and have managed to gather this information so far. Having used the RPM monitor the "Broken" pump seems to be spinning at 3400+ RPM same as my working pump with and without liquid involved. It just wont suck any liquid. :/

I'm using a Phobia nickel top I've got a theory that this may be the problem although I cant completely see how. Got a few more test I could do with it tomorrow maybe because its taking the liquid up first before it goes into the pump. This may be the cause of the problem never the less anyone with any ideas I wouldn't mind hearing them as I've heard OCUK is horrible for RMA and I'd rather try to fix the pump myself than send it off.

koooowweeee · 13 Aug 2010 at 13:03

i didnt think you could put a top on a mcp350.

if its not working and the other one is just send it back dont mess about with it

PaulyD · 13 Aug 2010 at 13:32

koooowweeee said:
i didnt think you could put a top on a mcp350.

if its not working and the other one is just send it back dont mess about with it

There are loads of tops availiable for this pump..

Its the exact same as Liang DDC.

Strange that its showing that its spinning but not actually sucking any liquid, have you taken the pump apart and tried moving the impellor to see if it sticks at any point? A little bit of gunk in there can do that.

You could also for a (very) quick test is plug it in with the top off and see if it spins, turn it off straight away as the pump needs water itself to keep cool and not burn out

R.C.Anderson · 13 Aug 2010 at 13:36

stick your ear near it, or hold it, is it spinning? if it is, have you checked the impeller is still connected to the motor?

koooowweeee · 13 Aug 2010 at 13:46

PaulyD said:
There are loads of tops availiable for this pump..

Its the exact same as Liang DDC.

Strange that its showing that its spinning but not actually sucking any liquid, have you taken the pump apart and tried moving the impellor to see if it sticks at any point? A little bit of gunk in there can do that.

You could also for a (very) quick test is plug it in with the top off and see if it spins, turn it off straight away as the pump needs water itself to keep cool and not burn out

i thought they were one unit guess not. i no you can get tops for mcp355 had a few xspc and ek ones.

PaulyD · 13 Aug 2010 at 13:49

Its exactly the same but a 10w version, aka missing some solder between two contacts..

koooowweeee · 13 Aug 2010 at 14:06

PaulyD said:
Its exactly the same but a 10w version, aka missing some solder between two contacts..

yes read a little about that solder mod just never seen tops for them

apparently not all of them you can do that mod on tho

PaulyD · 13 Aug 2010 at 14:08

Indeed some newer ones removed the point.

Just a bit of a bonus if you get one really

koooowweeee · 13 Aug 2010 at 14:15

PaulyD said:
Indeed some newer ones removed the point.

Just a bit of a bonus if you get one really

yea

dont no why overclockers dont sell mcp355 seems strange

anyway back on topic lol

as another poster said have you felt the pump when its on.

unscrew the top if you dont mind taking it apart and then turn it on for a second you will see if it spins or not

Skeng · 13 Aug 2010 at 15:11

PaulyD said:
There are loads of tops availiable for this pump..

Its the exact same as Liang DDC.

Strange that its showing that its spinning but not actually sucking any liquid, have you taken the pump apart and tried moving the impellor to see if it sticks at any point? A little bit of gunk in there can do that.

You could also for a (very) quick test is plug it in with the top off and see if it spins, turn it off straight away as the pump needs water itself to keep cool and not burn out

Yeah I've done that already had the top removed and seen it spin for a very short amount of time.

Also the impeller has been removed and put back in (it's just magnetic) and it seems fine it has nothing to catch on. The weird part is when I moved it in my case from the lower shelf of the 800D to a slightly higher drive bay. Some how in that transition it's stopped working :/ the strange thing is I just simply picked it up and moved it I wasn't harsh or dropped it or anything. :/

twist3d0n3 · 13 Aug 2010 at 15:19

is the pump actually getting liquid inside - i've had it before where it'll spin but not pump anything due to a bubble, and as the water pressure from the res isn't enough to shift it through it gets stuck...

PaulyD · 13 Aug 2010 at 16:12

twist3d0n3 said:
is the pump actually getting liquid inside - i've had it before where it'll spin but not pump anything due to a bubble, and as the water pressure from the res isn't enough to shift it through it gets stuck...

This was my next thought

Skeng · 15 Aug 2010 at 04:21

I'm going to check that tomorrow, I have a theory that the liquid wont travel up due to pressure. :/

(As in suck upwards from the res into the pump)

Bubo · 15 Aug 2010 at 10:13

So the pump is now above the res? You are right in thinking that a pump cannot suck water up a tube if there is a column of air on the inlet side of the pump i.e. in the tube between the pump inlet and res.. Pumps must be primed with water before they work. You must somehow get water to fill the leg from the res to the pump inlet and also at least fill the impeller housing. Perhaps you need to rotate the case when filling.

Once it has started pumping, and as long as when you switch the pump off the port on the res which goes to the pump inlet remains under water then you will be okay to keep the pump above the res.

Skeng · 16 Aug 2010 at 23:21

Bubo said:
So the pump is now above the res? You are right in thinking that a pump cannot suck water up a tube if there is a column of air on the inlet side of the pump i.e. in the tube between the pump inlet and res.. Pumps must be primed with water before they work. You must somehow get water to fill the leg from the res to the pump inlet and also at least fill the impeller housing. Perhaps you need to rotate the case when filling.

Once it has started pumping, and as long as when you switch the pump off the port on the res which goes to the pump inlet remains under water then you will be okay to keep the pump above the res.

Well I've filled bleed the air bubbles and had a good grappling session with my PC. The good pump is now cooling my GPU's and the other on cpu (of course). Unfortunately I'm idling at 38 degrees now and the pump must be broken as its not shifting liquid like my other does.

GPU res is full of bubbles and activity the CPU one is just dead.

Skeng · 16 Aug 2010 at 23:56

here's some pictures of what I mean.

Top bay is what I believe to be the fault pump

Hard to get a snap shot but as you can see its a good drop into the pump so shouldnt be any troubles sucking there.

PaulyD · 17 Aug 2010 at 08:17

38 degrees is still quite cool, if the pump was dead I would imagine it would be a lot higher?

Does it steadily climb up? I have had a pump stall and I idled at 70-80c

Bubo · 17 Aug 2010 at 08:36

Can you confirm that you had the cpu pump positioned above the res for a while, running it dry, then you've now put it back below the res?

Skeng · 17 Aug 2010 at 13:55

Bubo said:
Can you confirm that you had the cpu pump positioned above the res for a while, running it dry, then you've now put it back below the res?

I didn't have it running dry it had liquid in the first time when the res was slightly lower. I tipped liquid in then started it but it didn't seem to pump very good.

PaulyD said:
38 degrees is still quite cool, if the pump was dead I would imagine it would be a lot higher?

Does it steadily climb up? I have had a pump stall and I idled at 70-80c

What happens is I idle at about 40 degrees then it just keeps rising until it hits about 60-70 degrees by this time I turn off my PC for a while and go back on later. Takes it about an hour to do so. Gaming or anything too demanding is basically out of the question.

Every now and then I hear the pump (revving) like a car engine and it does little kicks where it pumps then stop, pumps again then stops again. lets say I'm idling at 40 degrees when it does this little pump session which lasts about 10-15 seconds my temps drop like 5 degrees immediately then once it stops they slowly rise again.

100% this pump is broken I even believe it's been broken since I've bought it. Thinking back when I had it cooling my GPU's the res was never too active slight activity just not as bad as this. Think it's got a little worse over the past 3 - 4 weeks I've had it set up.

Skeng · 18 Aug 2010 at 00:09

Well earlier today I turned on my PC the pump made a loud noise and then it completely stopped working. Now I'm using my spare pump whilst I RMA the broken one.