caldog20 Posted June 5, 2023 Report Share Posted June 5, 2023 Hi, I have a Balboa EL2001 Mach 3 board that is immediately displaying an OHH flashing code. It has the same behavior whether topside is connected or disconnected. I have done some research and came to the conclusion it is more than likely a bad component on the board. I have done some testing and possibly found a bad diode but it has no markings for identification. I can't order replacements to repair without proper identification of the bad components. Does anyone have detailed schematics or information on these boards? The diode at D7 seems to be bad but it has either gotten too hot and the markings are gone, or just faded. Quote Link to comment Share on other sites More sharing options...
cranbiz Posted June 6, 2023 Report Share Posted June 6, 2023 I see a heater relay that looks suspect. If the relay is shorted, that can easily cause an overheat situation. Relays are around $15 each. I would test the 2 heater relays and replace them if bad. Quote Link to comment Share on other sites More sharing options...
caldog20 Posted June 6, 2023 Author Report Share Posted June 6, 2023 1 hour ago, cranbiz said: I see a heater relay that looks suspect. If the relay is shorted, that can easily cause an overheat situation. Relays are around $15 each. I would test the 2 heater relays and replace them if bad. I tested them and each tested okay. Are you talking about the black line on the heater relay? That is a shadow from the picture. From what I understand the heater relay being shorted won't immediately throw an OHH code immediately on bootup? Quote Link to comment Share on other sites More sharing options...
caldog20 Posted June 6, 2023 Author Report Share Posted June 6, 2023 One thing I did notice is that even though it consistently blinks OHH, if I short the sensor leads on it displays SnA or SnB depending on which one I short. I checked each sensor and they are reading proper resistance based on water temperature. So it seems the logic is working to some extent for the sensor readings. Quote Link to comment Share on other sites More sharing options...
caldog20 Posted June 6, 2023 Author Report Share Posted June 6, 2023 I think I may have found the failure point. It looks like this area got extremely hot at some point. The resistors here look fried and possibly the 2 diodes. 1 Quote Link to comment Share on other sites More sharing options...
caldog20 Posted June 6, 2023 Author Report Share Posted June 6, 2023 (edited) D3 is a burnt diode for sure. If it had markings on it I could identify it's voltage at least for replacement. Edit: Found markings after cleaning with ~pure Isoprop. D3 is a 13V Zenner Diode and D7 is a 10V Zenner Diode. I am going to go ahead and replace both. I will update if that fixes the problem. Edited June 7, 2023 by caldog20 Identified components 1 Quote Link to comment Share on other sites More sharing options...
Michael H Posted June 7, 2023 Report Share Posted June 7, 2023 Ok this sounds promising as I have a EL2000 M3 in my Maax 461 Hot Tub that also just got stuck on OHH. There doesn’t seem to be a reason for this code to not reset so I will look at my board in the above locations. I will report back my findings tonight Thanks Michael Quote Link to comment Share on other sites More sharing options...
Michael H Posted June 8, 2023 Report Share Posted June 8, 2023 I see the area on the board with D3 and D7 and provided the image below Quote Link to comment Share on other sites More sharing options...
Michael H Posted June 8, 2023 Report Share Posted June 8, 2023 I see the area on the board with D3 and D7 and provided the some better images below Quote Link to comment Share on other sites More sharing options...
caldog20 Posted June 8, 2023 Author Report Share Posted June 8, 2023 2 hours ago, Michael H said: I see the area on the board with D3 and D7 and provided the some better images below I had to put an LED flashlight under the board to actually see how hot it got. From looking at D3 and the colorization, it looks like it got hot. Also the trace between D7 and R32 is darker, same as mine, probably due to overcurrent in that area. You can see on your board D7 has taken some damage. I am replacing D7 and D3 on my board. I also checked the 2 resistors that were darkened but they both checkout out at 150 ohms which matches their code. This area must have something to do with the sensor circuit for readings/comparisons between the sensors for checking for flow. If you look on the back of the board in that area, you will probably see where D3 got really hot and made a square mark due to heat on the board. I have read this can be caused by a stuck heater relay, causing resistance in the temperature sensors to drastically reduce, which can cause overcurrent in the sensor circuit when the temperature stays too hot for too long. Might be a good idea to verify heater relays as well. 1 1 Quote Link to comment Share on other sites More sharing options...
caldog20 Posted June 8, 2023 Author Report Share Posted June 8, 2023 Once my parts come in and I replace the diodes I will report back with my results in case anyone else has the same issue. No disrespect to the board repair people out there, but I prefer to fix these things myself if possible. 1 1 Quote Link to comment Share on other sites More sharing options...
cranbiz Posted June 8, 2023 Report Share Posted June 8, 2023 Why would anyone take offense? The whole premise of this board is to help each other fix their tubs. Some people have the ability to fully DIY, some don't. Go for it and let us know how you make out. Quote Link to comment Share on other sites More sharing options...
Michael H Posted June 8, 2023 Report Share Posted June 8, 2023 Thanks for posting this information as I now understand why my board stopped working correctly and that a board repair might be possible. I will do some testing of the board today if I get a chance to determine the faults I have also started to look at replacing the whole spa pack with a BP7 5.5kW and a TP700 which can then be connected to remote access with the wifi adaptor. Quote Link to comment Share on other sites More sharing options...
caldog20 Posted June 10, 2023 Author Report Share Posted June 10, 2023 I just wanted to report back with my results. I replaced 13V Zenner Diode D3 and 10V Zenner Diode D7, and the problem has been resolved. The board is working properly now, reporting proper temperatures, and toggling the heater on/off at set temperature. Thanks, Caleb 1 Quote Link to comment Share on other sites More sharing options...
Michael H Posted June 10, 2023 Report Share Posted June 10, 2023 This is great news and I wonder how I could repair mine. My neighbour is electronically handy so he might be able to help. How and where did you get the diodes so quickly? I tested my diodes and D3 is gone and D7 partially so I could use your help to attempt my repair in Windsor, Ontario. Do you have a repair picture th share? Thanks Michael Quote Link to comment Share on other sites More sharing options...
caldog20 Posted June 10, 2023 Author Report Share Posted June 10, 2023 1 hour ago, Michael H said: This is great news and I wonder how I could repair mine. My neighbour is electronically handy so he might be able to help. How and where did you get the diodes so quickly? I tested my diodes and D3 is gone and D7 partially so I could use your help to attempt my repair in Windsor, Ontario. Do you have a repair picture th share? Thanks Michael When I get back home I can give you exact links from Digikey to order parts. As far as picture it really looks no different. Just unsoldered old diodes, cleaned pads, resoldered new diodes and done. Quote Link to comment Share on other sites More sharing options...
Michael H Posted June 10, 2023 Report Share Posted June 10, 2023 Ok I’ll search for Digikey to see if I can source D3 & D7 Quote Link to comment Share on other sites More sharing options...
Michael H Posted June 10, 2023 Report Share Posted June 10, 2023 I did some searching but I’m not familiar with sites and the components being listed. If you can provide links then I’ll see if mouser.ca has them which I might be able to get on Monday Quote Link to comment Share on other sites More sharing options...
caldog20 Posted June 11, 2023 Author Report Share Posted June 11, 2023 16 hours ago, Michael H said: I did some searching but I’m not familiar with sites and the components being listed. If you can provide links then I’ll see if mouser.ca has them which I might be able to get on Monday 13V Zenner Diode - https://www.digikey.com/en/products/detail/diodes-incorporated/BZX84C13-7-F/775729 10V Zenner Diode - https://www.digikey.com/en/products/detail/good-ark-semiconductor/BZX84C10/18648842 Quote Link to comment Share on other sites More sharing options...
Michael H Posted June 11, 2023 Report Share Posted June 11, 2023 Thanks for the links to the replacement diodes and I will order these for my repair and hopefully the board will be functioning soon. I will report back on my repair and testing once I receive the parts provided in the link above. Thanks Michael Quote Link to comment Share on other sites More sharing options...
Michael H Posted June 16, 2023 Report Share Posted June 16, 2023 Expecting to get the Diodes today to do my repair this weekend and then return the my board to the Cottage Hot Tub next week for testing. I will report back in a couple of weeks 1 Quote Link to comment Share on other sites More sharing options...
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