brewGroup noisy on clockwise direction

[fkomat]

KSB
Do not have scope or Xformer now, pssibly I could get them at a later date.
Can you describe now what are the area to troubleshoot, if it is the MicroPro.
can you give the signal path points to follow, from source to destination for the
motor rotation cw and ccw.
tks

 

[ksb]

1. Mains synchronisation via 2x100k-resistors, and a zener-diode to µC input.
2. Control-logic for cw/ccw-direction via program in the µC
3. µC output to halfwave-triac via a gate-resistor

Please refer to Harrys great work:

Saeco Getriebemotor

 

[fkomat]

Ksb
I know it is difficult the do remote troubleshooting, and I am taking time from you. Can you provide me with any doc. that you have on pcb M4AV6-7, I realize that there is no diagrams for it, if you also could give some directions of what to follow or what to look for with this problem, I could spend some time followig your instructions, without this difficult method of troubleshooting .
Again tks for your support.

 

[ksb]

did you follow the link: Saeco Getriebemotor ?

 

[fkomat]

got Harry's diag. I will work on it, can you tell me the model I should follow for pcb M4AV6-7, there is no much info on this model.

 

[ksb]

The circuit of all "old" saecos is nearly the same.....

You can make a little experiment to make sure, that the problem is not caused by a leakage current via any tracks of the pcb to heatsink.

You need 2 diodes (2A / 1000V) and a 3-position-switch (on-off-on). Remove T8 and connect the left and the midle pin to switch and diodes (see schematic) CAUTION - your construction must be save !

 

[fkomat]

Great test, I'll try it, however my gut feeling tells me that the problem is as you described above "2. Control-logic for cw/ccw-direction via program in the µC". Any leakage to the heat-sink, I think would show on both rotation cw or ccw, I could be way off, but I think this is a Processor or related programming issue, I do not have familiarity or experience to back up my theory. If the above test is inconclusive I will assume that this is a MicroP issue and without a replacement I will call the matter closed.
KSB, you have been an excellent mentor, your English is superb, I wish I could understand German so I could read Harry's great work, the answer is there!! Thank you for your excellent support
Bye and good luck!
Fkomat

 

[ksb]

Hello fkomat,

it is possible to buy a used but tested pcb for a low price - for example from www.dicofema.at (christian speaks english).

regards KSB

 

[fkomat]

KSB
the challenge was to fix the damn board!! I will investigate the site, thanks!
fkomat

 

[ksb]

ok i wish you good luck !

Bye

KSB