Polar 76 sdp keyboard stop working

We repare faulty component on KUP card, replace BU426A by BU429 and small component in the picture.
Now keyboard machine is working normally.
Thanks,

 

Thank you sir.
Congratulation.
Good Job
Blessing.

 

Hello, I have a Polar 76-SD P cutting machine like the one in the previous post and what happens is that the machine works short, but the display does not turn on
I have checked the voltages of +9 volts and + 5 volts and they are correct, but the display does not continue to light up. I have changed the BDX 54 transistors but the display does not work. Any ideas?
Thank you

 

Hola Domingo:

I would like you to send me PICS, of the Regulated power Supply of:+5 + 9 VDC, to see if they are within tolerance.

 

Hello, thanks for your prompt response, I measured the two voltages and the +5 volts has 5.00 v and the 9 volts has 9.01 volts
If you have any idea please let me know.
Thank you so much

 

If those really are the voltages, you have 3 options:

1) Ribbon cable or flat cable test

2) Reheating the complete PCB, x : dry + colder Solder joint!!!

3) If it doesn't work, replace the whole PCB.

 

Thank you very much for your help. I need to repair this board; as I tell you, the guillotine works manually, the only thing that doesn't work is the display that is always OFF. Looking at the circuit, I have seen that it seems that the MC 14515B chip controls the display, is it correct? Could you try to replace it, tell me your opinion please.
Thank a lot in advance.
Greetings

 

My point is, did you do the steps I told you before?

Otherwise you will waste your time, polar, and many Reputable factories DO NOT give that type of electrical schematic wiring, because they would run out of business.

For this reason, try to do what I indicate, and as you know, your Polar machine is already old and spare parts are already difficult to find, only used.

 

I have just soldered all the pins of the ribbon cable connector on the board, the ribbon cable looks good, I have cleaned the connector contacts and I have soldered the pins of some chip, but the result is still the same, the display does not light up. Also, I can't find a spare part for this board here in Spain, so I need to repair this board. If you have any other ideas, I would like to hear any instructions in order to be able to repair this board.
Greetings

 

don't understand, because I told you to reheat the entire Keyboard board, and you're only talking about the pins, the pins could be part of the problem, BUT I told you to do a complete REHEATING of the board, clean it well, and do the complete REHEATING,

If that does NOT work, time to change the entire PCB. So try to do what I tell you, and as you know, your Polar machine is already old and spare parts are hard to find, only used.

 

Is there no decimal point or even a zero showing up in the display?

 

Hello, no, the display always remains off. What turns on when the machine is connected are two red leds, I don't know if that indicates a clue or not. I send you an image where one of them appears, it is marked as V37 and it is just On the right margin of the image, which is close to the display, the other led is right next to it, although it does not appear in the image, but the display itself does not light up at all, nothing appears (no number letter sign and no point on the display lights up).
Another detail is that when you start the ignition, the buzzer starts beeping. Once you enter a numerical value through the keyboard, the beep disappears.
But the display always remains off, no segment or point lights up.

 

In a couple of days I will carry out your idea of reheating the plate completely. Right now I cannot do it because the guillotine is working. As soon as possible I will do it to see if we get any satisfactory results, in what it tells me to replace the plate, at the moment it is not possible because I can't find a replacement, I'm looking to see if I can find a replacement plate but for now my efforts have been in vain.
Please, if you know of a page where you can buy this plate, tell me, it will be of great help.

 

1) reheat the plate please

2) Give me a photo + part number + guillotine model, and your email.

 

Hello, here is a general photo of the guillotine plate that has the number POLAR 017741 silkscreened, the model is Polar 76 SD-P
My email is: domingobesa at gmail.com
Any indication and information about this board is welcome.