Noritsu 2901 - all chems in working tank are COLD

[Big Dave 15]

Hello All !

Todays problem is All of the working tanks are not heating up even after 2 hours of warm up time.  Working tank temperatures did not rise.

All fuses on J390456 are ok (F1-F11 and FL1-FL4) all SSRs look good,  None are dark or burnt or damaged.

PCB J390564 is the same.  Everything looks fine.

No error messages were displayed.  

What could it be ?

thank you !

[davidlam 21]

Are all the working tank pump circulating ?

[davidlam 21]

since no error and problems applied to all chemistry... I would suggest problem with J390532 processor control pcb  -or- the PS11  +24v/36v power supply

see below their locations

[davidlam 21]

also the J390458 Processor connecting connecting PCB  is a good place to look at those LEDs to tell power supply voltage readiness 

[Big Dave 15]

Thank you @davidlam,

if I remember correctly, both boards in the back looked good, but will check voltages tomorrow.

[Dave S 75]

Check if LED 9 (SOLU) is lit on the Power PCB 1 (J390456)
Check LED 9 (SOLU) & 10 (LEVEL) are lit on the Power PCB 2 (J390564)

[Big Dave 15]

Hi DaveS,

yes, all the LEDs you asked about are on.

couple days ago, machine was making all the “right” noises, today, after about 5-7 minutes, the (I think) dryer motor turned off, so it “sounded different” today.

About a minute after the change in sound from the Noritsu, I just turned it off at the breaker.

 

 

Edited Tuesday at 12:03 AM by Big Dave
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[Dave S 75]

Are LED's 1, 2 & 3 lit on the Power PCB 1 when it says the solution temperatures being adjusted?

If they are, it will mean either there is no mains voltage going to the heaters, check fuses, F1, F6 and F7, make sure the fuses are tight in the holders or the relay X1 or X2 has gone bad on the Power PCB 1.

Obviously only check the fuses/ holders with the power turned off!

If LED's 1, 2 & 3 are not lit, it will be a control issue, basically it means the processor control PCB is not sending the signal to turn the heaters on.

Check the connectors J/P649 Power PCB 1 & J/P 511 on the Processor Control PCB.

[Big Dave 15]

Hi DaveS,

I took photos of those PCBs and yes LEDs 1, 2, 3 & 4 are ON

all fuses on PCB1 are good , cleaned and reseated.

SSR x1 and x2 visually look fine from the top, but do not know if they are failing.

The connectors you referenced on PCB1 and Processor control PCB are good and have been reseated.