Marvel Under Counter Ice maker All display lights flashing, Removed board didn't find anything burnt or shorted, service manual says user interface board lost communication to main board, Any help or test would be appreciated.
Your battery threw up on your comms. Looks like corrosion.
You have volatile memory.
Can no longer store information on your user interface, your settings.
The patient is dead.
Unless you know how to desolder & solder.
So... That chip was shorted out before you clean it up all you did is prepared the body for the morgue. There's no longer a load on that battery your meter will register a voltage on it but the damage is done.
You still want to play cat and mouse what else did you do my diagnosis stands. Time of death 3:17 Pacific time
IN MY MAGGING THAT IMAGE RIGHT ON UP . . . . . 600x . . . just at pixelation onsetting
What this 'ole boys eyesareaseeeeeeeing . . . . . . is a the utilization of a temporary charge duration. . . . . . SUPER E-capacitor . . . . . . being used, instead of a battery and a nearby 12.6 Mhz System clock oscillator (for u/p clock) and a nearby 8 pin EEPROM 24xx series (it needing NO memory power backup) program memory storage chip and a ST brand 32 pin system controller -u/processor up at near top.
It has one output port set feeding into the ULN2003 relay driver at the extreme top for the units multiple relays . . . . count 'em ! . . . . function switchings.
The board is being IPON conformal coated and has MULTIPLE surfactal leveling aberrations . . . . . particularly near and around multi connection components . . . . .thus leading to the shotgun multi directional light reflections .
That is making some think that the soldermanship or any detritus presence is being ch!tty ch!tty bang bang.
You show ONLY this controller board *** . . .
*** BTW these people made it for ( Captain) MARVELICE MAKER . . . . escapades ***
But there is the COMPANION board inside the unit with its temp display and assuredly an up and down temp push button set. PLUS the units temp sensor . . . . . which might have gone bad . . . or you have connections and inter wiring, yet to confirm as being good.
With there being no plug in connector in-continuity or a timely corrosive / oxidation build up onset.
We have yet to see a photo of that other board . . . but there is a 4 pin connector between the two boards, of which you can see the connector marked as COMM on your board.
Starting at the right end pin we see it connected to DC power. The next pin is ground.
We know that those two connections are a complete loop, since your display is working.
The next two pins are are being In/Out serial digital handshaking lines that transport data between the two boards. Both are having .1 uf monolithic ceramic block cap bypassing at the pins and further on down there is a set of series 100 ohm surface mount resistors in line before further connecting to 2 ports on the ST u/P.
Do as the display is telling you . . . . . confirm any loss of connectivity between / or / on the boards and find the temp sensor and confirm its changing resistance with temp change . . . . . or having the presence of a good junction in case . . . . instead . . . . if they are using a 1N4148 family of diode as a temp sensor.
Vell now . . . . after I'm dun bin tellink you . . . . . vat isht you dun bin thinkink ? (a la Herr Kapp)
I now be . . . . . . .
. . . . . . . ZUJ'ing
73's de Edd . . . . .
I just released my own fragrance . . . . . . but no one in the car seemed to like it.
SUPER E-capacitor . . . . . . being used, instead of a battery and a nearby 12.6 Mhz System clock oscillator (for u/p clock) and a nearby 8 pin EEPROM 24xx series (it needing NO memory power backup) program memory storage chip and a ST brand 32 pin system controller -u/processor up at near top.