Hitachi hcu-ax10e does not turn on
https://elektrotanya.com/hitachi_axc10.pdf/download.html
Check if this is your diagram and check the source and the key lines a button has not been attached
Indeed that is the diagram I have reviewed the power plate and in it I have seen that the R002 and the C018 capacitor were bad, the resistance should mark 10k and it marked about 36k we talked about everything desoldered, and the condenser too. I will replace them, do you think that could be the problem? I have checked around resistors and capacitors and diodes and every normal brand, also the Q001 transistor and the 7809 voltage regulator all that corresponds to this resistor and capacitor. Should I check something else?
Thank you
Ok, I made those substitutions and it turns on but none of the buttons works, just the volume and the power on and off? What part should I watch now?
Thank you
I understand that it is very possible that some button is stuck or sulfated and this blocks the other buttons I have run into problems so what else is Czech in the diagram the key lines q are the buttons and place them in physical ayaras 4.9 approximately in all the lines If you have a difference in them, kerra will say that the key line that this voltage drops is the problem, change the dial and test buttons and make sure that by pressing a button there is a voltage variation in the key lines.
I don't understand this last of the key lines very well, you can explain it a little better in what part of the diagram they are and how I should measure voltage.
Thank you
The key lines are the keypad lines or connections in the deven aver diagram and in physical, a print on the screen card is very likely to be attached with a flex to the main card but in that flex there are a few lines called key q are the buttons and go to the processor these are variants suwlen aver key 1 ke2 or more the point is that the key lines are the keypads matrices and each one has a boltage of 4.9 approximately I will upload an example
I understand that they are the key lines, now I will check them. Thanks for the clarification. However, I am thinking that they should not be the key lines because there are several and on different plates, that is, the one on CDs on the one hand and the control of the tuning up down equipment and others on the other, the volume one if it can be considered another key if it works then I see 2 key plates and that none of them work seems odd to me the truth, maybe the problem comes from a 7806 corresponding to the IC002 of the main power board ?, next is where I changed the resistance and the condenser.
It could be but discard the key lines is only measure and you did not understand me well the key lines are a group of buttons that is bolumen channel up down tunier etc. Grab a single key line and thus do not pass over 3 key lines
Now I understand you, I think. You can tell me where I would have to measure this, I'm a little clueless with this topic of the key lines and in the diagram I don't see it very clearly.
Thank you
I have checked the tension of the key lines as you have said specifically in the flex that goes from the cd card to the keypad that is the PG755 connector, taking as common the 7 and testing one by one gives me approximately 5.12 V in all except in 3 which is also mass.
Any more suggestions?
Thank you
I just inserted a cassette tape and when you press the buttons on the play tape on one side and the other the cassette deck goes a little crazy so the rest of the buttons do not work at all.
Thank you
As I go as before I have put I checked the tension in the flex of the cd card to the keypad that is the key pcb, In the flex I have taken the common that is 7 and I have been testing pin by pin in all I have 5.12V approximately except in which it is mass as well. Sometimes the display if I press the level, dolby or dynamic bass buttons starts to move, but that only. The volume regulator does work, since I pick up headphones and listen without a station and louder and lower. The rest of the keypad does not work
Thank you
Let's summarize a little to tell you to be a friend, so why the team says it turns on but the defect is that the buttons don't give the volume well and the speakers are heard
Exactly neither the CD trays nor station search nor function change only volume and standby button work
You can upload a photo of the device on and tell me if any message appears on the screen
Here I put the link for the photo
https://drive.google.com/open?id=1fiNaPMBH-cgKmTUKkiYXAWm1AvbDSf-Y
Only a message comes out of what you see, when turning on it sets hello and when turning off bye. Only that
It is a very old model friend I see in the photo that is on the radio by a speaker and see if you hear transmitter or at least a static screech
Check the ic 751 pin 93. 95. 96 q ayan 5 volts if they are perfect, proceed to test one because it happens when pressing a key if there is variation of voltages
I just checked on pin 95, 1.8 V arrives and 93 and 96 arrive 5V. I press the keys one by one and there is no voltage variation on any of the pins.
Thanks for the help friend
You already gave your friend a problem because it doesn't obey your buttons, it turns out there is a button attached or something short on that line, because I have to see 5 volts, check page 27 of the friend diagram, as I said, a button or the button is very possibly pressed resistance turned https://elektrotanya.com/hitachi_axc10.pdf/download.html
Friend, I have to tell you that I made a mistake in the measurement I made without wanting to take pin 94 which is about 1 V. Now I have measured on the pins that you told me in conditions and they all arrive approximately 5.12 V, I have tried to press the cd and band keys and so on and there has been no variation in the voltage on any of the pins.
Thanks friend
The same friend as I said we already support the problem we are in that the problem is a resistance of step is damaged or that the buttons are already in poor condition I check the plane and I indicated to you that I check it again
What if I'm going ahead of you on the buttons on one of its pins, I should see 5 volts as that measurement while please and comment
I have measured on the 3 buttons of the CD and there are indeed 5 V on one of its pins
Check f751 of 1 k and r954 of 10 k check the buttons as I said a pin has 5 volts and the other 0 volts now this is tested on the push pin pin that there are 5 volts it measures that a 5 volts measures if this voltage drops to press the vote not to fall the pin that has no vote as a bridge to ground gnd and retry again not to happen anything even so change the buttons all
Eye tab and seja
gnd you take out of the chassis or pin 2 of the infrared or the pg751 connector pin 6 must also have gng
When you say to make a bridge to ground gnd do you mean that in the button of the button where there is 5 V put earth? That would not be a short no? Or do you mean that if there is a button that does not have the 5 V, it will be bridged to ground? I have not understood you very well.
Thank you for your help, friend
A friend, on the other hand, the buttons on one pin have 5 volts and on the other pin you have 0 volts, it is not a short one, even if it looks like it, the button always carries a pin to the ground, it is a pull up circuit, the pin if you look at the flat page 27 see the push buttons a pin is gnd and I want to discard it with this test is if the fault is due to bad push buttons or for lack of gnd I upload a photo of how they work to be clearer friend
I can not upload photo but check this link
https://m.facebook.com/377107416138523/photos/a.378047872711144.1073741828.377107416138523/400394870476444/?type=3&source=48 Look at the image of the pull up button is how the buttons on your device work with the difference that this is a Matrix and the processor knows that the key weighed by the direction of current that it detects, as I said from GND or ground chassis as a bridge and only bites the pin of the buttons on the pin and the 5 volts just one touch and tell me with that you jump the push button to make the order of said button
Friend I have done what you told me tested the resistors R751 and R954 and they are correct, I have also given a pinch to the 5V pin with gnd and prize when doing that the team responds perfectly. What am I supposed to do now?
Thank you very much, my friend.
As I said in the beginning friend EURECA WE HELP THE PROBLEM AS THIS
IN THE PIN BUTTON THERE IS 5 VOLTS AND IN THE OTHER NOTHING SOLD A CABLE FROM EARTH TO THE BUTTON TO THE PIN Q THERE IS OR VOLTS AND TEST IF THE BUTTONS ARE GIVEN IF THEY DON'T CHANGE ALL THE BUTTONS WITHOUT EXECUTION AND SO THE PROOF AGAIN WITH THAT SOLVED
Hello friend, we are moving forward, I am going to tell you what has happened I have done what you told me to weld a cable to GND and the button still did nothing, then I thought if it is the button with the tester in continuity should not whistle, indeed I measure in continuity on the buttons of the button and it does not give continuity and what is my surprise that by doing that that button already works, I have done it at 3 of the cd and the one of function and they work perfectly, although it is true that They are quite hard to press, what does this suggest? Change the buttons as you said right?
Thank you very much
If as I said change all the buttons without any exemption and put the cable from the ground again to the pin of the button that does not have a vast voltage that you wear it in one and all will work friend
The cable must be left in place forever or I just sting it and that's it?
Thank you very much for your help friend, it is a pleasure to work with people like you and this community.
The cable is test domes when you put the new buttons, but it will not be missing, but if you do not leave it to any button to the pin that has 0 volts, it will not cause any failure this areglo
The cable is test domes when you put the new buttons, but it will not be missing, but if you do not leave it to any button to the pin that has 0 volts, it will not cause any failure this areglo
Don't forget to rate a friend so this post will be for the support of another person
I do not forget as soon as it is repaired I will rate it with a very good grade.
Thank you
Friend good again.
I don't know what happened but I have a new problem. The other day I went to ride it and when I mounted it, I couldn't hear anything at all, but if it turned on, the keypad went perfectly. Now the result is that it no longer turns on, I only hear the click of the relay and it does nothing or the on / standby LED turns on. What I can do?
Choco some cable what indicates is source failure check very carefully maybe I connect something wrong only
The connection is checked all, I have disconnected and reconnected, probably as you say some cable collided or the board with the chassis is very possible. Where should I start looking?
Thank you
Open a new question
Com what you say that does not turn on anything go first to the source that delivers voltages
52 minutes ago manuel-241's Avatar
Manuel-241
Indeed that is the diagram I have reviewed the power plate and in it I have seen that the R002 and the C018 capacitor were bad, the resistance should mark 10k and it marked about 36k we talked about everything desoldered, and the condenser too. I will replace them, do you think that could be the problem? I have checked around resistors and capacitors and diodes and every normal brand, also the Q001 transistor and the 7809 voltage regulator all that corresponds to this resistor and capacitor. Should I check something else?
Thank you
Ok, I made those substitutions and it turns on but none of the buttons works, just the volume and the power on and off? What part should I watch now? Thank you
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