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 June 30 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.

 

[Big Dave 15]

On 6/30/2020 at 4:17 AM, Dave S said:

or the relay X1 or X2 has gone bad on the Power PCB 1.

@Dave S  Is there a way to test those 2 relays without removing the pcb ??

[davidlam 21]

A silly question from me..

if your machine is a 3 phase machine.. will that be Any 1 of the 3 phases tripped without your awareness ?

[Dave S 75]

If you are confident measuring live voltages, you can measure between the screw terminals T1 & T2, there should be 220-240V AC

You can also check the mains voltage between Fuse F1 & F6, again should be 220-240V AC.

The relays X1 & X2 will be the black squarish relays, they are not SSR's.
There is no easy way to easily test them without removing the PCB and testing it on the bench. Would have to apply 24V DC to the relay coil and check the resistance of the contacts using a multimeter.

If you have a spare power PCB 1, I would just swap it out.
Take a photo of all the connectors and terminals before you swap it as a reference.

Make sure the machine is isolated from the wall socket before you swap the board.

Edited Wednesday at 10:20 PM by Dave S

[davidlam 21]

i find a photo in eBay, here you go

 

[davidlam 21]

@big dave,,,, are all red jumpers there on your board ?