Hi, i need your help guys!! I can´t find the datasheet of the next chip

MisterBill2

Joined Jan 23, 2018
3,884
I am trying to repair this device. apparently everything is fine, but it doesn't work. so I'm testing component by component.
Evaluating an inoperative piece of equipment a part at a time is a very tedious approach. A more logical way will be to evaluate the functionality of sections. Is the printer "Stone Dead?", or not? A logical search would start with verifying that the power switches on and that the correct voltages appear at supply pins. Then would come an examination of outputs, to see if they were reasonable levels. Wit an IR data port, verifying that the LED puts out and that the photo-detectors are working is a logical step. LEDs do occasionally fail, and photosensors have been a source of many failures in the devices that I have repaired. Not a total failure, just a loss of sensitivity. So looking at the functions that don't function is a better way to find the problem.
 

Thread Starter

Diego Coll

Joined May 15, 2017
7
Evaluating an inoperative piece of equipment a part at a time is a very tedious approach. A more logical way will be to evaluate the functionality of sections. Is the printer "Stone Dead?", or not? A logical search would start with verifying that the power switches on and that the correct voltages appear at supply pins. Then would come an examination of outputs, to see if they were reasonable levels. Wit an IR data port, verifying that the LED puts out and that the photo-detectors are working is a logical step. LEDs do occasionally fail, and photosensors have been a source of many failures in the devices that I have repaired. Not a total failure, just a loss of sensitivity. So looking at the functions that don't function is a better way to find the problem.
Hi, thanks for helping me with this problem.
I already did the conventional steps to test the hardware. I measured the source and the regulatory stages. I did a visual and electrical inspection and everything is fine.

+ the device turns on
+ the buttons work
+ the electric motor works
+ the paper presence sensor works
+ I measured the lines of communication and they work well

RX signal:
MVIMG_20191002_003356.jpg

TX signal:
MVIMG_20191001_232609.jpg

It just does not print...!!

I'm going to do a couple more tests and if it doesn't work. I will finish the repair work.
Anyway, thank you very much for helping me.
 

MisterBill2

Joined Jan 23, 2018
3,884
Is there another way to send data to the printer aside from that IR link? That would allow you to verify that the rest of the system is OK.
And as for the visual inspection not finding anything, many electronic failures are inside devices and have no visible problems. And when a part burns up, usually that is caused by some other part not being right, So replacing the burned part is the small part of the repair. The question is always why did it burn up?
 

Thread Starter

Diego Coll

Joined May 15, 2017
7
Is there another way to send data to the printer aside from that IR link? That would allow you to verify that the rest of the system is OK.
And as for the visual inspection not finding anything, many electronic failures are inside devices and have no visible problems. And when a part burns up, usually that is caused by some other part not being right, So replacing the burned part is the small part of the repair. The question is always why did it burn up?
Unfortunately the only method of communication is by IR. As I mentioned before. I did a visual and electrical inspection, measuring many of the components and everything seems fine. I'm already frustrated with this device. hahaha.
Again I want to thank everyone for helping me..!!
 
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