Laing DDC pump repair PCB mod

[wizard1238]

Hi all,
I don't understand if there's a PCB repair/mod kit (soldered) for my Laing DDC-1T 3.1 modded to 3.2 with blue impeller/rotor?

Those're my laing pics:






Thanks for answer

please refer to #90...

[colex]

please refer to #90...

Thanks for reply.

I think it's best don't make mod for the owners of this pump revision!

[DumpALump]

I have mine on order, but I don't know how long it takes to get to California. I'm going to install it into a DDC 3.25 pump with aftermarket XSPC top.

I took a look at the datasheets and wanted to figure out the power dissipation. Plugging in the typical for Im, Ron(H), and Ron(L) with 12v and 2.35A I get 3.3675W. According to the spec sheet a value of 39C/W is given for a 140mm x 70mm x 1.6mm 50% CU board. Since swiftech's pumps are only 60mm x 60mm and the board has a big hole in the middle, I'm just going to assume the second rating given which is 65C/W. So P = ~219C. I think I read somewhere that the base gets to about 50C and that is on the plastic. So Tj = 3.3675W x 65C/W + 50C = ~269C. Of course I'm not factoring in the heat removal by the water.

Maybe I messed up somewhere, but it doesn't look like this would work or for very long in a 3.25 since the thermal shutdown is 165C-180C. Datasheet also says to keep under 150C Tj. Didn't really think of this before ordering, though I wish the IC was mounted to the other side of the PCB. Then at least I could put a heatsink with direct contact onto the IC.

[Martinm210]

Yeah, I don't think I would consider using this board on a blue impeller motor. If you want to try it out, it should work well on bmaverick's DDC-1 pumps though. They are the original black impeller DDC-1 and DDC-1T motors.

[lowfat]

Will it work on these PCBs? I ordered two of the ebay DDCs that use the expansion compensators but they don't seem to work. I was hoping just to through the new PCB on them.

[Martinm210]

That looks like a DDC3 series PCB. Does it have a blue impeller?

DDC-1 series look like this and have a black impeller:

[SpuTnicK]

Yeap

This is the rare special edition Laing DDC-3.2VC with built in liquid volume compensator. It is the much more reliable and newer BLUE rotor 18W version with the original LAING 3.3 PCB.

Source

[lowfat]

That looks like a DDC3 series PCB. Does it have a blue impeller?

Yes they are blue. I think I may still try to mod them though. I'd rather not just have these two dead DDCs laying around.

this board is designed for the black and purple rotor DDC1/DDC2, use in the blue rotor DDC3 is left for diyer to play The extended wire may have chance to short circuit the board, it should be very careful. When using with blue rotor DDC3.x and stock top at full speed, the current is about 2.1A, it's still within the safety limit of this chip(1.5A typ. 2.5A max) Use with aftermarket top is 2.35A, I would recommend connect a resistor between VSP and Vref to reduce the current.
1. if the pump restarts every 3 sec, most likely the TB6588FG need to be resolder it cannot read the feedback signal from the coil. it's very common.
2. the toshiba burn immediately if the leg short circuit/bridging due to soldering problem. remember to wear safety glass, the chip can explode when connecting power. Page 8 of this document have the information, it is available in english but only can found in toshiba japan web.
http://www.semicon.toshiba.co.jp/doc..._en_090317.pdf

Shame I haven't taken any electronics after high school as this just went WAY over my head.

I tried to read over the spec sheet but it just looks like a bunch of gobbledygook to me.

How would I find out what size resistor is going to be needed between VSP and Vref in order to keep the amperage at safe levels?

Yeap

Source

Ya those are the ones I have and they don't work.

[SpuTnicK]

lowfat
So basically you have bought the item that don't work? care to get your money back? oh BTW, what that fourth cable is for (the red one)?

How would I find out what size resistor is going to be needed between VSP and Vref in order to keep the amperage at safe levels?

I would suggest to use a potentiometer, connect it to those pins and turn it off, then try to start the pump and increase the resistance step-by-step.
Though even 2.35A is safe for this chip, according to this

[DumpALump]

How would I find out what size resistor is going to be needed between VSP and Vref in order to keep the amperage at safe levels?

Like SpuTnicK said you'll probably have to just connect a pot and guess. I finally received my kit and it looks like VSP is being fed from Vref to set VSP to 5v.
Vad(H)<VSP<=Vref = 100% speed
Vad(L) is 1.2v and Vad(H) is 4.1v
I'm not sure what current is flowing through it, but it looks like either 1mA or lower. We want to drop the 5v down to at least 4v. So using Vdrop / I = R
1 / .001 = 1000 ohms.
2 / .001 = 2000 ohms.
etc...
If the current was lower then it'd be a greater resistance. So make sure to start out high then reduce resistance. I'm still debating whether I want to install it on my pump or not. I was thinking you could use the motherboard to control it, but VSP requires an analog signal, so no pwm

[lowfat]

lowfat
So basically you have bought the item that don't work? care to get your money back? oh BTW, what that fourth cable is for (the red one)?

There was never any mention of warranty on the eBay page and they did work for a while before dying out. The red wire is for 5V, which I am not sure why it is there but the pumps wouldn't work without it.

EDIT: I finally got my pre soldered DIYINHK PCB. I can see the problems w/ installing it on a DDC 3.2 already. Since all the coils are soldered to the inside of the PCB instead of the outside it is a tad on the difficult side of things to remove them. Plus the coil wires are too short to reach where the need to be on the new PCB.

[Sparky]

The 5V is probably to feed the logic of the control chip.

[lowfat]

I got the old PCB's off my DDC3.2s. There are 6 coils w/ two wires a piece. However on the new PCB there are only 10 holes for wires to pass through AFAIK. There are two more places where I think the wires should go but no holes to push them through.

[SpuTnicK]

The holes are in places where electric contact from one side of PCB should pass to the other side. So, i guess you should not worry about that, as it is more of PCB developer's duty. Just solder all 12 wires to those contacts and the board should work as planned.

[wizard1238]

connect like this, and be care the two ending of each coil cannot be reverse connected.

[penguins]

This is Certainly off topic.

but, Lowfat nice picture of that pcb.. it's so photogenic.
and I love John Criton and Mal.

that is all.

[lowfat]

Getting close. I just hope it works afterwards.

[mochti01]

Looks good. Keep us posted. I'm actually waiting about 3 weeks for my circuit boards... And of course good luck!!

[wizard1238]

double check the copper wire is not touching/short circuit the PCB before connect the power. it should work immidiately

The PCB can also be place outside the pump housing, you have very long copper wire extended. The heat from the controller will never go into the water loop in this arrangement.

[Martinm210]

Cool!...

[Rise]

I'm really confused after looking through all of the posts... which PCB will work for the blue impeller ddc 3.1?

[lowfat]

Well I got it completed but it isn't working properly. It is trying to pump but it just spurts on and off about 2 times a second. Moving almost next to no water though.

[serialk11r]

Been a while since I posted here...

Anyways, does anyone know if this would work on the original DDC-2 with ORANGE (gasp I know right) impeller from 2007? I'm thinking about selling mine soon and given it's poor reliability track record, this mod being available might bring peace of mind to whoever may be interested in buying it. Certainly doesn't look too hard to solder the few wires on.

[Martinm210]

Well I got it completed but it isn't working properly. It is trying to pump but it just spurts on and off about 2 times a second. Moving almost next to no water though.

Thanks for trying and sharing, sounds like it's a DDC-1 only mod..

[serialk11r]

Wait so just making sure, by DDC-1 you mean the old 10W one before they switched to 3.1 and 3.2 right? I thought the PCB for the DDC-1 (black) and DDC-2 (orange) were supposed to be very similar, so could it work on an orange impellered pump?