Author Topic: Spa Computer Help  (Read 6626 times)

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Offline vortex_690

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Spa Computer Help
« on: June 26, 2017, 10:23:08 pm »
Hi all

I have a spa computer that I have been trying to get going...All it does is flash one light on the controller after a while being plugged in the controller
starts to show a few lights and partial digits


I have tried a few things with no luck I am not experienced in electronic repair very much at all but I am learning as I go

So far I have done the following

I have replaced the capacitors with new ones as this was suggested as a common fault

I have tested the bridge rectifier and got the following results
14.06 dc volts
11.83 ac volts

Then I have tested the Micro Controller AT9054433-8PC and got the following results
4.94 dc volts pin 7 vcc
pin 8 ground
3.86dc volts reset pin 1

Any help I would appreciate it

Cheers Chris
 

Online DaJMasta

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Re: Spa Computer Help
« Reply #1 on: June 26, 2017, 10:36:24 pm »
Does the spa still function, just with the display damage?  It sounds like the micro is at least active, I would take a look at any circuitry that are part of the display/input device, and perhaps another chip that directly controls the display (it could be directly connected to the micro, though).


Are there any obvious sensors coming from the spa?  Perhaps part it is a fault in a sensor that prevents the system from running.
 

Offline vortex_690

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Re: Spa Computer Help
« Reply #2 on: June 26, 2017, 10:55:01 pm »
Hi mate

The spa does not function at all no response from the controller it doesn't even turn on the blower or pump as it should when you first Power it up

The only sensor it has is a water flow / temp sensor


 

Online DaJMasta

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Re: Spa Computer Help
« Reply #3 on: June 27, 2017, 09:19:02 pm »
Do you have a scope?  Could be worth monitoring the power and reset lines of the micro just to see and be sure.  Otherwise, multimeter on the sensor lines as a sanity check (and maybe some resistance checking on the pump and blower to make sure they're in the right ballpark).

If you can get into the front panel board (if it's separate from the one pictured), you may get some extra info.... if it can be disconnected from the micro board, maybe disconnect it and see if it gets any farther in booting.


Without knowing the system design and without a good idea of how it's all connected... it's tough to narrow it down.  You're getting at least a partial power up, but whether it's stopping because of an error or if something's corrupted or stuck is tough to say.
 

Offline vortex_690

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Re: Spa Computer Help
« Reply #4 on: June 27, 2017, 09:40:41 pm »
Hey man
I don't have a scope only the the multimeter

The controller does unplug from the unit when unplugged it does the same

The blower and pump are external power plugs that pug directly into the computer

The computer turns those power plugs on and off with the controller saying that it doesn't know what those devices are it only knows to switch power on and off at command

On power up the computer should switch on the powet to those outlets to go through self diagnostics

So the heater whitch is connected to the computer directly detects if water is moving through the pipes and if not should switch the power off to the outlets

Last time i got one of these fixed it cost me like 500.00 so was trying to do it myself....not looking to positive for me lol
 

Online DaJMasta

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Re: Spa Computer Help
« Reply #5 on: June 27, 2017, 10:14:49 pm »
Ok, I missed that those were the relays in the first pic, and it's probably good that it acts the same way when unplugged from the front panel because you can narrow it down to this board.

It may be good to trace out the reset pin to see if it connects to something which could be bringing it down - while 4V should be sufficient to keep it from resetting, it may be an indicator of something being bad on it that is pulling it low at some point fast enough that your multimeter can't pick up on it.


I don't have a lot of experience with this sort of design, but it seems clear that the micro is driving the relays through the ULN2803... but I don't see any flyback diodes on the relays.  Could the surge generated from switching have killed the ULN2803?  If that's the case it's pretty bad board design.... but this guess is a shot in the dark, at best - it could be that the relays chosen have it integrated or generate small enough reverse currents to not be a problem for the Darlington array.


It could be worth checking power signals around the board, or maybe watching the signals coming into the ULN2803 (you can find which pins would be the transistor bases on the datasheet) just to make sure the micro is actually trying to turn them on.  If the micro is damaged or the firmware corrupted, then it could be replaced, but the problem is that you probably don't have a spare copy of the firmware, so even if it were replaced, it would still need the right firmware to work with the system.
 

Offline james_s

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Re: Spa Computer Help
« Reply #6 on: June 27, 2017, 10:21:05 pm »
When mine failed it was bad electrolytic capacitors in the power supply. I had a previous problem with a cracked solder joint causing it to think the water flow sensor wasn't functioning but that was a long time ago.
 

Offline wasyoungonce

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Re: Spa Computer Help
« Reply #7 on: June 28, 2017, 12:01:02 am »
A Spa controller model number will hep...also some more pics of the PCB...from above/behind.

Are you in Australia...these appear to be Davey controllers??

Brendan
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Offline vortex_690

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Re: Spa Computer Help
« Reply #8 on: June 28, 2017, 10:13:18 pm »
Hi all

Sorry for the late reply

It is a spa quip controller which is now Davey

Its a Spa Power 500A

I'm In Sydney Australia
 

Offline james_s

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Re: Spa Computer Help
« Reply #9 on: June 28, 2017, 11:38:28 pm »
I'd start out by replacing those three electrolytic capacitors. Cheap to do and they are about the only electronic component that wears out with time and use.
 

Offline vortex_690

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Re: Spa Computer Help
« Reply #10 on: June 28, 2017, 11:43:37 pm »
Hey dude

I already replaced the 3 capacitors
 

Offline james_s

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Re: Spa Computer Help
« Reply #11 on: June 28, 2017, 11:53:21 pm »
Oops, sorry I missed that part.

There is not much to that board, just a microcontroller with a relay driver chip, should be able to trace which pins go to which function and then poke at the input and output pins to see if there's any activity.
 
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Offline wasyoungonce

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Re: Spa Computer Help
« Reply #12 on: June 29, 2017, 12:28:59 am »
Thanks for pics...was looking at C11 polarity...its ok from the extra pics.    There are a couple of links J1/J2/J3 with +12V is that ok?  Also is pwr getting to the pwr pins of the IC's?  What is U4 part number...an opto coupler?  Its from the water flow sensor.  Is this shutting down the PCB?

As said by DaJMasta  check the ULN2803 for in and out voltages.  The Micro might be sending signals but they might not be getting thru.

edit:
re-reading the original post and looking at the controller documents...brings me straight to "any error codes"?.  In the original posy you said...
......I have a spa computer that I have been trying to get going...All it does is flash one light on the controller after a while being plugged in the controller starts to show a few lights and partial digits ......

Did any of the partial digits look like the error codes listedhere...warning downloads a small pdf.  of in the controller documentation.

If the display is garbled then it could be usually a bad display controller IC...in this case this would be the micro-controller.





« Last Edit: June 29, 2017, 12:49:41 am by wasyoungonce »
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Offline vortex_690

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Re: Spa Computer Help
« Reply #13 on: June 29, 2017, 01:42:31 am »
So this time it displayed nothing after 5 mins i got random lights nothing corresponding to the error sheet

h11aa1 0315k is the chip U4

4.94 v j1    5v+

14.93 v j2  12v+

14.21 v j3  12v+


ULN 2803 14.03v both sides on all pins the control panel changes at random when I was testing this chip

« Last Edit: June 29, 2017, 01:58:04 am by vortex_690 »
 

Offline wasyoungonce

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Re: Spa Computer Help
« Reply #14 on: June 29, 2017, 02:32:15 am »
Ok thanks....is there any inputs to the ULN28003 that are high?   Aka an output high from the microcontroller. I'm guessing a high from the micro turns on the respective ULN2803 driver which supplies a gnd path to the appropriate relay.  Just a re-read...14V on both sides of ULN2803, all pins, ...that's not right.

If none high or its not the ULN2803...and since you get garbled display...and the display has no driver IC...then the micro controller is looking suspect.  You also might be able to trace back the display to the microcontroller lines to see if they are ok.

If it is a micro....best thing is to try module repair in Ringwood (there are in other places).  I've used them for a dishwasher controller repair I couldn't fix myself (yes I admitted defeat!).  They were a lot cheaper than a new controller.

The h11aa1 is an opto transistor coupler.

edit:
ok 12/14V both sides of the ULN2803...which will put the same voltage onto the outputs of the microcontroller.   Might be best to pull the ULN2803 out.  Cheap enough...cut the legs carefully hit the left over with solder and pull the left over leg pins with tweezers or pliers.  Clean up with solder  wick. 

Or at least cut one leg that goes to the microcontroller lift it and measure the microcontroller pin...is it ok now?  I'm assuming the microcontroller outputs a high to the ULN2803 which drives a low out to the relay coils making them actuate.

Its possible this has damaged the microcontroller.

« Last Edit: June 29, 2017, 03:58:10 am by wasyoungonce »
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Online DaJMasta

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Re: Spa Computer Help
« Reply #15 on: June 29, 2017, 05:46:53 am »
I think pulling the ULN2803 is the right call, then if the micro is still acting up (garbled display and all) you know it has also been damaged, while if the display seems to normalize, maybe just dropping in a new driver chip will fix it.

Normally, 14V is way too much for a micro, and I certainly don't see any significant protection, but maybe you're lucky and there are some protection diodes that have kicked in.

The 6 pin dip is definitely in the spot for an optoisolator, not totally sure what it's feedback for, maybe power line cycle timing?  Maybe it feeds into an ADC to get a level?
 

Offline james_s

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Re: Spa Computer Help
« Reply #16 on: June 29, 2017, 07:22:29 am »
If the microcontroller is bad then it's pretty much game over, unless you want to try to write new firmware from scratch and load it into a replacement chip. That could be a fun project but it's not easy unless you're an experienced programmer.
 

Offline Armadillo

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Re: Spa Computer Help
« Reply #17 on: June 29, 2017, 09:55:43 am »
Break up into 2 portion of Checks:

1: Microcontroller Health
2: Peripherals

Let's Check Item 1 first;

Pin 7 VCC: Measure this voltage with respect to Pin 8. Should be 5V.
Pin 20 AVCC: Measure this voltage with respect to Pin 22. Should be 5V
Pin 21 AREF: Measure this voltage with respect to Pin 22.  Between 2V to 5V
Pin 10 XTAL2: Measure this voltage with respect to Pin 8. Should be some voltage near around half VCC. Best is to use a digital logic probe if you have one. This pin is critical to whole operation. Because there is a ceramic resonator there, not destine to last. Consider to borrow one digital logic probe or buy one about $20 versus $500.
Pin 1 Reset: Measure Pin 1 to Pin 8. Should be 5V. Your reset pin is not normal at 3.86V. Its a Resistor connected to VCC to a capacitor. Check why not pulled to 5v. Example wet, moisture. Measure the resistor ohm. Lastly Change the capacitor at this Reset Pin.

let's identify is the microcontroller running normally or abnormally before Proceeding to Part 2.
« Last Edit: June 29, 2017, 07:35:01 pm by Armadillo »
 

Offline james_s

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Re: Spa Computer Help
« Reply #18 on: June 29, 2017, 05:03:12 pm »
I suppose it might be worth replacing the resonator if everything else looks ok. I don't think I've had one of those fail but I have had a few quartz crystals go bad and oscillate wildly off frequency.
 

Offline drussell

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Re: Spa Computer Help
« Reply #19 on: June 29, 2017, 07:50:15 pm »
+1 for having a logic probe, it makes troubleshooting many digital things MUCH easier when you haven't yet graduated to having a full blown oscilloscope.  :)
 

Offline vortex_690

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Re: Spa Computer Help
« Reply #20 on: June 29, 2017, 09:28:13 pm »
hi all

thanks all for the help I'm learning lots and lots lol

I'm not sure about pulling the ULN2803 that would be a very difficult task I think unsoldering the chip I recon I would bugger it up LOL

I will try to get a logic probe today not that I know how to use it yet lol

Writing new firmware no luck there wouldn't even know where to start....YET

I have measured the info as requested

Pin 7 VCC: Measure this voltage with respect to Pin 8. Should be 5V.               4.96
Pin 20 AVCC: Measure this voltage with respect to Pin 22. Should be 5V           4.95
Pin 21 AREF: Measure this voltage with respect to Pin 22.  Between 2V to 5V    4.95
Pin 10 XTAL2: Measure this voltage with respect to Pin 8. Should be some voltage near around half VCC. 4.96

Because there is a ceramic resonator there, not destine to last. Which one is that is it the little yellow bulbs at C5 and C9

Pin 1 Reset: Measure Pin 1 to Pin 8. Should be 5V. Your reset pin is not normal at 3.86V.  Still 3.86V

Its a Resistor connected to VCC to a capacitor. Check why not pulled to 5v. Example wet, moisture. Measure the resistor ohm. Lastly Change the capacitor at this Reset Pin.  No sure which resistor    .... The capacitor is the smaller one of the 3 next to c13 which I have already changed or is this wrong one I'm looking at

I suppose it might be worth replacing the resonator if everything else looks ok.    Where Is the resonator is that the blue one at CR1

Thanks all
Chris
« Last Edit: June 29, 2017, 09:43:22 pm by vortex_690 »
 

Offline james_s

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Re: Spa Computer Help
« Reply #21 on: June 29, 2017, 09:40:19 pm »
You can use a wire to jumper the reset pin temporarily to the +5V pin, that will force it out of reset, or to ground, that will force it to reset.

The ceramic resonator is the blue thing labeled CR1. It should have the frequency printed on it, 4MHz is a common value.
 

Offline vortex_690

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Re: Spa Computer Help
« Reply #22 on: June 29, 2017, 10:34:22 pm »
Its funny i was actually thinking of doing that
 

Offline vortex_690

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Re: Spa Computer Help
« Reply #23 on: June 29, 2017, 10:52:37 pm »
Bumped it to 4.96 no change
 

Offline vortex_690

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Re: Spa Computer Help
« Reply #24 on: June 29, 2017, 10:56:47 pm »
This is the blue one with numbers
 


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