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info tech
info tech, Technician
Category: Recorders and Players
Satisfied Customers: 15814
Experience:  Technician for many high street outlets 20 years plus experience
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Panasonic DMR EX77 - DVD / HDD Recorder. We have returned from

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Panasonic DMR EX77 - DVD / HDD Recorder. We have returned from holiday and while we were away the clocks changed from BST. We had set the unit up to record our favourite programmes and normally the unit would compensate for the change. During start up, the unit display shows an error message U16 which according to the instructions means that a recording malfunction occurred. When powered up we get the default channel one with a message to the effect that the self check did not complete and invites us to press OK when the DVD tray is supposed to open and then the unit resets. However none of this happens and all we can achieve is to switch it off (by holding down the off button for 10 seconds), restart and the error messages return. Whilst the error message is on, neither the remote nor the buttons of the unit make anything happen so its impossible to access the function menu. I have tried pressing the channel buttons simultaneously to no effect. By holding down the DVD drawer button the unit starts up with no error message and the default channel, however there is no sound and again no other functions via remote or unit switches. All cables appear connected.
Thanks for the Question
Have you tried rebooting?unplugging from the wallpower waiting 5 mins then re-plugging back in again?
Let me know about that first please
Customer: replied 3 years ago.

Yes I've tried that too.

OK I will dig out the service data for this unit please reply back in an hour or more from now
Customer: replied 3 years ago.

What does that mean. Do you want me to reply or will you????

I'm here now I am just going through the data on this will be about 5 to 10 mins
Sorry for prolonged delay had to wait for this info
OK what you aim to do is to get the unit into engineers service mode (meant only for technical)you do that by having the unit in OFF mode so then you press
CHANNEL UP>>OPEN\CLOSE>>>RECORD Buttons ON THE UNIT itself simultaneous and hold them for 5 seconds you will see SERV in the window, then press 9 then 9 again you should see CLR in the window, switch the unit ON then OFF wait 5 mins then switch ON again, when I say ON or OFF I am referring to the in standby out of standby modes NOT the plug at the wall
Let me know if you have any problems
If its good could you please rate the answer positively thank you
Customer: replied 3 years ago.

The unit responded pretty much as you described albeit quite slow to react at each stage. However, having done all this (the whole operation took about 20 minutes); on restarting the fault messages appeared again and the unit locked out. It will now only switch off by disconnecting the power (I left it 30 minutes after pressing the standby switch to see if it would power down without this).In desperation I tried the procedure again, with exactly the same reactions and outcome.

So it did go into service mode you did get the SERV message and CLR up?
Customer: replied 3 years ago.

Yes. There was a small "D" above the "C" in CLR if that is relevant?

Hi Reg

Do you know the exact year you bought the machine please?

Customer: replied 3 years ago.

I'm sorry I don't. We purchased a package of Panasonic TV and home entertainment kit about 6 years ago. My wife thinks that this unit was replaced after the original one went wrong during the warranty period; but I don't recall this. We used a specialist Panasonic dealer in Dorchester, Dorset UK.

The serial number is ***** R if that helps?

Reg I can tell you the problem is bad firmware, this data controls the machines on-board computer and when it goes corrupt this is the sort of thing that happens, their is no upgrade of firmware at panasonic so their is little you can do yourself, if you took it in to a panasonic service agent for dvd they will charge over £100 to replace the eeprom with the firmware on-board so thats your call however because of the age of the unit I would consider replacing it.
Sorry for the poor news

Let me know if you need more info

Customer: replied 3 years ago.

Hi, Well thanks for being honest. I guess nothing lasts forever. Its clear that you have tried your best to help me however I am now £20 down with an expensive replacement on the horizon. I don't understand the concept of the"deposit" I paid. Does this now mean that I get the money back?


We are techs here who give our time to help for a fee now I am sorry that this did not work out for you but the answer is correct you would not have known this info had you not asked the question and if you took it in usually they take money off you for an assessment sometimes £30_£50, now I dont get any fee unless you rate the answer positively, otherwise my time supplying you with this info is wasted.

I do hope you understand this and reconsider

If you want a refund let me know
info tech and other Recorders and Players Specialists are ready to help you
Customer: replied 3 years ago.


Understood. We all have to make a living.

Thanks for all your help.