Panasonic DMR-EZ48 VHS-DVD combi.
I have three customers who have and use the Panasonic DMR-EZ48 VHS-DVD recorder combi machine. The recorder also has Freeview. Panasonic stopped making the machine three years ago.
The machine which is the subject of this discussion has given me a bad time. The fault code "U81" would appear, particularly when playing VHS tapes. First inspection revealed a 120mfd capacitor had gone bad, duly replaced and the machine returned to its owner. A few days later the same report, U80 and U81 fault codes. Things are getting serious. After completely dismantling the machine five more bad electrolytic capacitors were found, so these were replaced. Reassemble the machine, test, now the VHS deck doesn't work. Dismantle the machine again to check that the components were correctly fitted, which they were. Reassemble the machine, this time things got worse, the front panel now displays "Please Wait". It's suggested that new firmware must be loaded. Can't do this so I attempted to phone an excellent firm in Newcastle called Audio Vision Services. soon discovered AVS had gone into liquidation last year, that's another repairer gone! Things are getting desperate. Anyway, I went back to the workshop last night to have another look at the machine. It was still displaying "Please Wait" and did so for fifteen minutes or so, then, all of a sudden the machine sprang back into life again. The tape drum rotated, the tape spooled into the cassette. Everything works again! Let's see what happens when I return to the workshop later today.
Hope it’s settled down, faults like this are a real pain, especially if it’s a paying job, profit can soon go out the window.
Not an uncommon fault on these machines and their predecessors, I'm afraid. The long, alternating "PLEASE WAIT" message usually occurs after the mains has been interrupted for a long time. I've seen DVDs with the firmware on offered on eBay, Till - I had one some time ago to reactivate one of these very machines at work.
The fault is, as you've discovered, electrolytics in what is (I think) the 1.8V supply for the Freeview board.
Here is a tech. bulletin for this machine which causes a lot of problems like you have on this range of machines.
These may have been the ones you have already replaced though.
"Low 5V C1236(680uF @ 6.3V) and C1209(680UF @ 25V), replace both"
I do have the FW and instructions for updating, however you will need a blank CD-R and a means of burning said disk, (A CD-RW won't work it has to be a CD-R).
I can upload the latest Firmware zip file (needs unzipping first when you get it) and the pdfs of instructions and FW chart up to my dropbox account for you tomorrow evening if you need it.
Good evening Gentlemen,
Many thanks for your input, this machine certainly is giving problems. Hi Baz, thanks for the information, it's possible I might have missed the 680uF 6.3volt capacitor C1236. Two other 680uF capacitors have been replaced along with a few others of different values. The machine was returned to it's owner this evening. The VHS and DVD decks are working, at least for playback. I haven't tried to do any recordings. But there is now another fault, no colour from the built in Freeview tuner.
I know of another DMR-EZ48V machine which does strange things from time to time. It's owner knows to disconnect the machine from the mains to perform a reset. However, I was called to look at that one last week but it was only the remote control handset that needed attention. The rubber contact pad and PCB needed cleaning. When the menu button was pressed the Sony TV would go into a blank screen condition. All's well now after the Panasonic handset was cleaned. Strange one that.
The strange thing is - in the personal computer world at least - is that Panasonic have a reputation - deserved or otherwise - for making THE most reliable electrolytics!
According to the Panasonic FW Chart this model was a 2008 model (so approx. 11 years old) and the last and latest FW revision available was November 2009, not sure how long they were in production for but I do know there were a few FW revs early on in the life of these machines to cure various early teething problems, I hope this helps.
The latest FW chart available from Panasonic for this and similar machines of that range is dated 2010.