Another SM74 Error 15

Hi Everyone,

Trust you've all been well?

I have an error with our SM74-6P3+L 2001/626

This is the order of events:

1) Press turned off, gone home
2) Switch it on the next day, error 15 with the red T (machine wont move)
3) Board from another machine was tested, worked ok, but autoplate wouldn't release plates
4) After reading a few threads on here, I jiggled the brake and cleaned a damaged photocell on the feeder
5) The machine ran perfectly after this, for one day.
6) Machine switched off, turned on the next day. Error 15 back and now also with 'Malfunction in cabinet error.
7) I have moved the machine manually and also moved the brake, no change.
8) DYN Test is on REK 1 is showing: FFFC

Any help would highly be appreciated, the levels of stress are increasing!

 

Just to clarify, I have two errors:

1) Fault with operation
2) Malfunction in cabinet.

 

Hi sir hope you are well
After checking the DYN test on REK1 showing FFFC: The result is:
-REK1 found that the CPU REK2 no longer works .
failure of software in REK2 process occurred below the algorithM(main program exceed the current time)
Please procedure according.
Remember REK1 is microprocessor that receives information from sensor or swtich indicating if work or NOT
Attached is little block diagrams, that i did prepare for Basic concept of CPU or microprocessor.

 

Hi,
Is it solved or you still have problem?

 

Thank you both for your messages.

In a very strange set of circumstances, the machine is now working again. No errors.

What I did:
- moved the machine manually for a revolution
- then opened and closed all the guards
- cleaned the photocell on the feeder
- cleaned all delivery and feeder with compressed air.

A few times on and off and it seems to be ok now - hope it stays.

@CHOCK

I will study your post and image and come back to you.

Thanks,

Hiten.

 

ok
Let me know.

 

Hi CHOCK,

Thanks once again for your reply, I was wondering, how would I know which sensor or switch this may be? The error is back today, but only 'Fault Detected During Operation' with the red 'T' in a circle and the yellow T with the two arrows.

Regards,

Hiten

 

Hi Mr Hiten:
i did explain that in the basic condition any sensor or switch send information to CPU.

But this is not His case, since the fault is problem with : REK1 found that the CPU REK2 no longer works .

I believe that you must replace the Board CPU REK2, since the CPU is heart of the any computer.

However you can try this:

1) Perform a visual inspection : look for loose and broken wires, improperly seated connectors, loose or broken wires
misset switch, missing jumpers. and so on.
Chech for obviously damaged component(components burned or discolore due to overheating);

2) Reseating Boards and components:
Edge connectors are a common souorce of problems. Power down the system and remove the PC boards. Examine the edge connector
for contamination and clean with contacts cleaner contacts. Reseat any loose components 9suc as scoketed ICs) . Reseat the
boards and power up.

3) Power supply checks:
Check the power supply for missing voltages and voltages out of spec. A digital multimieter DMM can be necessary, as
voltage specifications are quite tight: logic supplies for example: must be within + 0.5 percent of 5Vdc. All the
multiple supplies and all must be checked.

4) Board swapping:
Board swapping involves the substitutiono of a known godd board for a suspect one.


5) Clock for CPU:
Check the frecuency with frequency counter or a DMM included frecuency counter( like Fluke DMM)


6)Reset CPU:
reset cpu see the attached schematic.

 

Hi CHOCK,

Many thanks once again for your concise message, I about to try and get these things you have suggested and see what result, if any I get.

Regards,

Hiten

 

Hello,
I faced some issue like yours, the front lay photo cells RL12 was the reason, please check it.

Please tell us when you solve the problem.

 

Dear Mr Hiten:
Hope you , can fix it.
Otherwise you must replace the board.