Laing DDC pump repair PCB mod

[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.