acurbelo

12

hace 5 años

Hello Sergio,
Thanks for your answer. In the initial question you will find the photos of the circuit. If you can't download them let me know to post them again.

Sergio A. González

103

hace 5 años

Look at the photo File new.png in the lower left, there is a transistor that cannot be read correctly. I think it is Q141 and a D143 zener. You should first check the presence of about 60V in the diode quartet D101 at the + and - poles. It would be very good to disassemble the transistor Q141 and the zener to do the tests. If you lived in Pinar del Rio I could do the job. regards

Sergio A. González

103

hace 5 años

If the problem continues, we continue to work on a line protector that is above the quatrain that also lines the line. I hope you solve.

Sergio A. González

103

hace 5 años

He had not read his explanation well, if he does not turn on a very quick test is made to determine the level of breakage, first the transformer must give about 6.5V, second in the heatsink of the 1117 regulator there must be about 3.2V IC302. The 1117 is disassembled and measured with a meter in the OMH resistance mode and from that point and ground it has to give about 250 ohm or so. If the measurement is low impedance, the microcontroller may be short. Greetings.

acurbelo

12

hace 5 años

Thanks again Sergio for your help. The transformer of this team was the first to die, so what remains is to repair the base. I will follow your advice to see if I am lucky.

Sergio A. González

103

hace 5 años

You can go commenting on what you are doing to help you more. regards

acurbelo

12

hace 5 años

If I am going to check the regulator. Do you know if this is fed directly from the transformer or is there any protection stage before?

acurbelo

12

hace 5 años

Sergio do you know if there is any way to replace the Panasonic headset display? I have another team that broke the connector tape and I would like to know if there is any way to replace it. As I have found out, it is only possible with a specific tool that Panasonic service centers have. Any suggestions are more welcome!

Sergio A. González

103

hace 5 años

I want to tell you that I have done my best to replace them and I have not succeeded. regards

Sergio A. González

103

hace 5 años

From the input of the transformer until 1117 there is only one 1 A fuse of the SMD type. regards

acurbelo

12

hace 5 años

Thank you, colleague, your recommendations are very accurate. The 1117 gives me in court between 1 and 2, I measured it in the circuit because I don't have an SMD station, so I guess this is the cause. What do you think?
Unfortunately the Panasonic colleagues put the display so that only they could repair it or they really do not conceive that their terminals are used for so long as to break the tape
connector

Sergio A. González

103

hace 5 años

Well I can tell you that if there is a cut between the heatsink and earth, you have the main tablet or micro controller in short. I have never been able to repair any. In relation to the tapes it is very difficult to repair and then sticking them again complicates everything. Good luck and regards

acurbelo

12

hace 5 años

If I thought so, I would like to measure the regulator off the board anyway to discard it completely. In my opinion in this circuit Panasonic saved a lot in protections, because they could have designed something safer against downloads. Grateful again!
Do you know any "local" solution to repair headset keyboard? I changed the pads so I presume it is wear in the connecting ink. I have reviewed everywhere but the solutions that offer none have worked for me ...

Sergio A. González

103

hace 5 años

After thoroughly washing the keyboard with detergent, I clean each number one by one with a thick cloth and rub it until it loses its shine and that greatly improves the contacts. Previously I cut the contact with a sharp blade and put another with the help of a small copper staple, I didn't like that and I didn't do it anymore. regards

acurbelo

12

hace 5 años

Actually with this keyboard I have tried almost everything and soon fails again, the only thing that remains is to rectify all contacts with connecting ink but as you know that in our conditions it is almost impossible. Grateful for your advice!