Paul-Ashton.com

I bought the Panasonic DMR-E85H when it came out a few years ago, and I’ve been very pleased with it, but this year it started having problems.

Symptoms (in chronological order)….

1. Stage 1: The TV picture flashed when changing from HDD to DVD
2. Stage 2: The machine switched itself off when burning a DVD
3. Stage 3: Sometimes the machine would start up, sometimes it wouldn’t
4. Stage 4: If the machine started up, it switched itself off when changing from HDD to DVD, when burning a DVD, opening the DVD tray or waking up from sleep mode
5. Stage 5: It would no longer start up. The Self Check at start up repeated endlessly

First I looked at the latest machines in the shops, but they are still very expensive, don’t support Blue-Ray , don’t have a network connection, don't support DVB-T and are basically not up to speed with the current technology for the price they are being sold at.
So I searched the internet for a solution, although this is usually a waste of time since I (like most people) don’t have the knowledge, tools or experience to try and repair solid state electronics. Personally I have a bit of experience with a soldering iron, but circuit diagrams are a mystery to me.  
As it turned out this problem is well known, but not so well documented. It affects the 55 and 85 series of Panasonic DMR HDD recorders. In a lot of cases people had problems 2.5 years after they bought the machine.
The problem is with a voltage regulator on the power board. The component is fixed to a large heat sink, but apparently the heat sink is not large enough, since eventually the heat it generates kills it. If you replace the component, the machine should work again; although it must be assumed that the component will eventually fail again. The repair is not difficult.

Since I have the DMR-E85H I can only write detailed instructions for this machine, although I suspect that the DMR-E55 is almost identical.

Parts:
The component is the Voltage Regulator STRG6353 / STRG 6353 from Sanken, sometimes listed as STRG6353 SKN. I bought it through a third party Amazon dealer and it costed  < 10 Euro.

Tools:

1. Medium cross screwdriver (magnetic)
2. Small slot screwdriver
3. Soldering iron
4. Solder
5. Solder remover (solder sucker, braid etc.)
6. Heat sink paste (as used for computer processors) - optional. Panasonic didn’t use any paste, which may be part of the problem

Instructions – DMR-E85H:

1. Remove the top of the case. One screw on each side, three on the back.
2. Remove the front panel. Five clips – One on each side, three on the bottom. When the panel is off, note the white plastic piece next to the display (left). When I put the front panel back on, this piece popped off, and it took me a while to work out where it came from. It simply tunnels LED light to the front display (as I know now).
3. Remove the screw fixing the black data ribbon cable to the hard drive frame.
4. Remove the data cable and power connector from the hard drive.
5. Remove the hard drive. The Power Board is underneath the Hard Drive. The hard drive is held in a frame and the frame is fixed to the bottom of the case through the Power Board. There is no need to take the frame apart. Simply remove the frame inclusive the Hard Drive by removing the four screws which hold the frame on the Power Board (are screwed through the Power Board). The screws are deep in the machine which is why a magnetic screwdriver is best.
6. Now the Power Board is accessible. There is now only one screw fixing the Power Board and this is on the back of the case where the mains power cable is plugged in. Otherwise the Power Board is held in place by two pegs.
7. Remove the Power Board side of the connector which connects the Power Board to the Main Board. There is a clip on the side of the connector, and it is easy to lever out with a small slot screwdriver.
8. The Power Board sits on two pegs on the right hand side. To remove it simply lift it up on the left hand side until the pegs release it. You will have to hold the last mentioned connector out of the way while you do this.
9. Now you have the Power Board in your hand and you can replace the component. If you are not familiar with soldering techniques, there are many sites on the internet which may be helpful.
10. As mentioned the component is screwed to the large heat sink on the power board, next to a huge capacitor. The part number is printed on it.
11. First you need to remove the solder from the 5 leg joints. Leave the component screwed to the heat sink while you do this. Be careful with the small ceramic components around the solder joints. If you hit one with the soldering iron / solder sucker it can easily crack. In production these components are fixed to the board with solder paste and hot air, since they can even crack with the direct heat of a soldering iron.
12. When you think the leg joints are clear of solder, remove the screw fixing the component to the heat sink. Test if it is free, but… Important!! – do not push the legs from the heat sink side of the board through the board! To test if the component is free, only pull it from the heat sink side. If the legs are not completely free and you push it, it can rip the tracks off the board.
13. Remove the component
14. For heat sink paste – clean the heat sink with a little petrol (or similar). Apply the heat sink paste to the heat sink where the component will be fixed.
15. Put the new component on the board and screw it to the heat sink
16. Solder the legs
17. Put the machine back together
18. Finished

Sorry there are no photos here. This description was an afterthought. Now I have the machine working, I don't really want to take it apart again. But if anyone wants to send me some photos I'll be happy to include them.

I wrote this description in the hope that it will help other DMR users by appearing at the top of a search. The information that I found in the internet was pretty basic and distributed. Of course, there is no guarantee that this will fix your machine. The problem is well known and there are a lot of people making a lot of money fixing it. Panasonic is no longer showing any interest.
I have described the symptoms which were caused by this component failing in my machine, but there may be other cases which lead to similar symptoms.  Simply put…  I accept no responsibility for any attempt to fix a machine with this description. If you follow these instructions correctly then your machine may work again.

Good luck.