My Issue(s) with the Pentair Intellicenter Hardware

I do think Pentair's flagship Intellicenter automation system is pretty slick with it's color touch screen interface and built-in web access, and I've been asked why I still run an Easytouch on my pool...

Before I get to that, I don't pretend to consider myself qualified enough to pick apart an electronic design from a twenty billion dollar corporation but I do I have experience repairing hundreds of Pentair boards and the following is my opinion, based on my observations.

My beef with the Intellicenter is that the boards are less robust than those of the discontinued Intellitouch and Easytouch, and they are more difficult - and often impossible - to repair.  For those reasons I haven't installed one on my pool, although I do have a working Intellicenter system on my test bench.

I've purchased or have been sent 30-ish damaged Intellicenter systems - some were just the base i5P panel (consisting of two interconnecting boards and a display) and some included expansion boards like the i8PS or i10D.  Of these I've been able to repair less than half!!  Such a low success rate could very well indicate a lack of skill on my part but I think it's primarily because the system is much more complex, the componentry is much smaller, and ALL the firmware is not available.

From left to right, chips 1-4 are for the Intellicenter... the first two are
power supply parts, the 3rd is a comm chip, the 4th is an Intellicenter
relay driver, and the 5th (rightmost) is an Easytouch relay driver. 

The Intellicenter is just a tiny Linux computer - an "almost-Raspberry-pi" if you will.  It's got a a TI Sitara processor, flash memory, a chunk of ram, USB circuitry, an ethernet interface, a lithium battery charging circuit, various types of I/O etc. - but the system also employs multiple power supplies and PIC32 microcontrollers (firmware not available)... and you're just flat out of luck if a PIC smokes - even if you can replace the chip.  In contrast you can rebuild an entire Easytouch from parts that you can actually see, and then program it with the latest firmware.

I understand that it's not in Pentair's interest that we repair our own systems and this is not meant to be a commentary on "right to repair", and I also understand that component selection depends to much extent on what parts - and package options - are available, but a few of their design decisions make repair difficult to impossible.  Here are my gripes:

1. This is a marketing decision rather than a design one, but I'll say it anyway... Pentair only sells a "complete" replacement i5P panel.  Remember the i5P has 2 interconnected boards and an LCD... often the failure occurs on the top board but you cannot buy just the top board - you need to buy a "complete" panel with top board, lower board, display and new plastic bezel, when frequently the failure is a two dollar part.  This decision obviously makes it exceedingly expensive for the consumer but also generates a ton of e-waste.  If you're going to make the thing un-repairable, at least let us buy individual boards.

This is what you have to buy if your Intellicenter dies

2. The relay drivers are impossibly small and are now soldered on - these are ULN2003 chips in a TSSOP package, similar in function to the ULN2803s which came in a much larger DIP package and were socketed on previous systems because everybody knows they frequently burn up!  Also, I can barely even see the resistor networks used to protect the Intellicenter's drivers!!  That Pentair decided to save a few cents by forgoing sockets and instead use drivers in an impossibly small package is maddening... we're meant to buy a new $500 board when a $2 relay driver eats it??  They could have used the tiny TSSOP parts on a replaceable $5 daughter board (heck, call it $50 with markup). 

Burned relay drivers and resistor networks

3. Firmware for the expansion cards is not available - each of Pentair's expansion cards (i8PS, i10D, valve module, cover controller etc.) have their own power supply and use a PIC32 microcontroller to communicate with the main i5P system (and maybe the other connected cards?) - which I think is pretty cool except the firmware for the PICs is not available.  This means that even if you replace a blown PIC32 chip you can never reprogram it, so another expensive card becomes e-waste.

Here's an i10D with a dead PIC32 (U2, on left side)... I could replace
it but the firmware isn't available so the board is garbage.

4. A voltage regulator used on the lower main board and the expansion cards seems to be more susceptible to surges than that of the old Easytouch/Intellitouch systems.  The old systems, including transceiver cards and indoor/wireless remotes, all use an LM1084 linear regulator (less efficient) whereas the Intellicenter has a 5 volt switch-mode power supply (SMPS) built around an Richtek RT8289 chip, which is an 8-pin SOIC with a "die attached pad", or DAP, on the underside... it's difficult to remove without damaging anything else.

You can see the pad under the RT8289 (U16) I removed from the board.  

Unfortunately U11 (and much else) is also dead on this one.

About half of the boards I've seen have had burn holes at the input pin... The RT8289 has a maximum input voltage of 34VDC (volts DC) and the input comes from the 18VAC (volts AC) secondary on the transformer - which works out to about 22VDC after rectification.  You wouldn't normally see much over 22VDC at the input, so a 34 volt max should be ok but surges can and do occur - and something frequently kills this Richtek chip.  My first thought was the max input was exceeded and the device failed catastrophically.  Maybe there's not enough headroom on the input voltage?  Or maybe it's something else in the switch mode supply?  I don't know.  Pentair appears to have used something close to Richtek's reference design but I don't know what component values were selected.

An expansion card's RT8289 with a hole blown in it at the input (pin 7)

Anecdotally, out of 300-ish dead Easytouch/Intellitouch boards I've only encountered ONE dead LM1084 regulator, so the LM1084 seems much more durable.  I recommended to a guy who'd blown up 4 Intellicenter boards over a couple of weeks that he re-install his Easytouch while he waited for the power company to fix a recurring surge issue caused by a nearby pump station - I figured when the ET blew up it'd be easier/cheaper to fix - but it never had a problem!... he kept it and gave up on the Intellicenter altogether.

End gripes.

Do with this information what you will... I sent Pentair a report and was told that a team corroborated my findings and would recommended solutions.  While I don't actually expect them to change their product based on the musings of a semi-professional-amateur-tinkerer I can dare to hope.