Questions abot Panasonic DMR E-85h repair and soldering.

[dafoe]

This unit acted up for a while. Eventually I got the "please wait" error message that the e85h is famous for. I googled the issue and it was suggested that faulty capacitors were to blame.

I disassembled the unit, and sure enough, capacitors 1270 and 1271 were bloated and leaking. I didn't have any way to measure the dimensions to order replacements online. So I put off the project.

The unit has been sitting around (in pieces) for well over a year now. And it's time to deal with it. I am going to just get the capacitors from Radio Shack. The other problem is I have never soldered before. But I want and need to learn.

So I'm not really sure what to buy. I just want something cheap to start out with. Once I gain more experience, I can upgrade my tools.

I found this kit on ebay: http://www.ebay.com/itm/Soldering-Iron-Gun-Rosin-Core-Solder-Wire-Desoldering-Pump-Suc...item35c17a3dbe

I was just wondering if this would be good for desoldering the old capacitors and soldering the new ones in place. For a beginner

Any advice would be greatly appreciated as this is completely new territory for me.

Thanks

[nic2k4]

That's a nice looking kit, but that desoldering pump is useless to remove components. At best you can use it to clear up holes once the part is out. Also, that iron is too hot you should be looking for something between 30 and 40 Watts. A 60 W iron is good for anything with a large area and lots of metal (that acts as a heat sink) like RF shields, metal tabs, stacked RCA connectors... Another thing missing is flux, you'll need it to clean the tip of your iron and tin it the first time you use it.

Check youtube for videos on soldering techniques. A few things to keep in mind:

- first thing to know, always keep your iron tip clean (shinny), use a wet sponge to wipe it every time it gets dull gray

- too much heat will de-bond the copper traces, use a low power iron (even better get a temperature controlled iron) and don't apply heat too long

- most components have a maximum temperature, depending on the iron that temperature may be attained in more or less time; you should be able to solder a pin in less than 5 seconds, if you can't do it leave it to cool down and try again

- when soldering components with many pins, don't solder all the pins at once and alternate sides to reduce local heat buildup

- to remove a component cut the pins off and desolder them one by one, if you can't get to the pins, apply heat to one pin and gently push the side of the part in the opposite direction, remove the heat to that pin and do the same to the other; this will gradually rock the part out without putting too much heat to the traces

You should note that some capacitors have a polarity, if the ones you have to replace do, make sure to mark it on the board so you can put the replacement in the correct direction.

[jman98]

The unit has been sitting around (in pieces) for well over a year now. And it's time to deal with it. I am going to just get the capacitors from Radio Shack. The other problem is I have never soldered before. But I want and need to learn.

In a worst case scenario, you may brick your player. It happens. I have only done some very simple soldering in my life and a few years ago, I bought a 3rd party add in component that could be soldered into a Pioneer DVD player to make it region free. I bricked my player. Maybe you'll have better luck, but after that I don't do soldering where there's very little room for error. I would NEVER attempt what you want to do.

[mammo1789]

In a worst case scenario, you may brick your player. It happens. I have only done some very simple soldering in my life and a few years ago, I bought a 3rd party add in component that could be soldered into a Pioneer DVD player to make it region free. I bricked my player. Maybe you'll have better luck, but after that I don't do soldering where there's very little room for error. I would NEVER attempt what you want to do.

Common Jman98 don't scare the man soldering capacitors or IC on the board is very easy and with proper (temperature controlled solder gun ) very fast. There plenty of treads at avs forums with explanation and pictures very illustrative and most of them on that forum are amateurs in soldering also and they have done it save them a lot in cost sometimes more then 400$ which is allot

some of the tread's that I have visited
http://www.avsforum.com/t/1055111/whither-the-capacitors-in-panasonic-recorders

try it, it is easy

[dafoe]

Thank you very much for the advice. I will try Radio Shack. They had a 25 watt pen. I thought the kit had flux.

Anyway, I figure the worst case scenario is that I damage the power board. I just want this resolved. Either I fix it and put it in my media center. Or I throw it in the trash. I'm just sick of it sitting there in a disassembled heap.

I know soldering is a skill and I don't expect to be great at it to begin with. But I need to start somewhere. This is a good place. If the recorder was that important to me I would have fixed it a long time ago. I'm mainly just interested in getting it resolved and getting some practice.

[Hoser Rob]

You should never use a 60W or even 40W iron on a modern PCB unit unless you're extremely good at soldering. And soldering is harder than it looks. You shouldn't use more than 25W.

I agree with the warnings/caveats above but if you brick it I don't see where you're losing much. Most electronic kit nowadays isn't worth spending the hourly rate that technicians need to charge.

You don't need soldering flux unless you're soldering your water pipes or something like that. The solder you buy for general electronics has flux in it already.

You also shouldn't need desoldering bulbs. The copper braided wick is better.

Before you try on a pcb it'd be a good idea to just practise soldering some wires together.

Rule one: heat the connection, not the solder. Place the tip where the parts join. When the connection is hot enough you can touch the solder to the wire or board ... not the iron ... and the solder will melt and flow into the connection.

If you don't do this ... ie. get impatient and just melt the solder on the iron ... the flux won't evaporate and the connection will mostly be a layer of flux between the part and the board. This is called a cold solder joint and it's guaranteed to fail. Just a matter of time.

Rule two: After the above step, do not move the connection until the solder join has solidified. It should look smooth and shiny.

[turk690]

I disassembled the unit, and sure enough, capacitors 1270 and 1271 were bloated and leaking. I didn't have any way to measure the dimensions to order replacements online.

It's easy enough that those capacitors appear defective & therefore need replacement. Soldering skill problems aside for the moment, however, my experience has proven in many cases that in a typical appliance like that VCR, a majority of the big electrolytic capacitors (100μF and bigger) are in fact defective. It's just not as obvious because they will neither be leaking nor bulging. One can desolder them and test them and test values will likely be spot on with the typical -20% to +80% electrolytic capacitor tolerance range but they will be as dead &/or dying as their leaking counterparts. A better way to test will be with an ESR (equivalent series resistance) meter (if you really want to know that bad). It's not unusual for me to replace more than 20 capacitors in a VCR PSU. Electrolytic capacitors can be considered an Achilles' heel of electronic equipment & I consider them fair targets if they are >5 years old &/or the environment the appliance is used in is hot, humid, dusty.
Lastly, even with industrial or pro VCRs, the electrolytic capacitors are commonly of the 85°C variety. I replace them always with 105°C (solid electrolyte or not). There is another problem there to look out for: a proliferation of fakes & substandards. Having handled rafts of these capacitors, the market is filled with those that IMHO are wrongly labeled (as 105°C, when they are anything but); they bulge & leak (& even explode) even sooner than the ones they replaced. Ordering them online is no guarantee: I have received some from even reputable vendors (farnell/newark) but I don't think it's deliberate; one just has to have an eye out for it constantly.

[dafoe]

Picked up a soldering iron (25 w pen) some desoldering braid, some 62/32/2 0.22 inch rosin core solder Monday night at Radio Shack. It was a little over $23.

What I didn't get were the frickin' capacitors. I read a tutorial that suggested getting 1000uf 25v capacitors at Radio Shack. Even listed the part number. So I went to Radio Shack and they had the capacitors. I wasn't terribly concerned that the original capacitors were only 860uf 16v. I figured an upgrade wouldn't hurt. But then I noticed they had a temperature rating of 85 vs 105 on the originals. 20 degrees seems like a lot to me.

So I went home and rechecked the Radio Shack website. Searching for the particular capacitor on their website was impossible. Which sucks because I really wanted to get this done this week.

So off to ebay I went. And I was lost. There are so many different terms that are complete gibberish to me . And I have no way of knowing what size I need because I have no way of measuring the originals. I am soooo frustrated right now.

Does anybody know where I get these capacitors with a positive and negative lead that will actually fit a Panasonic DMRE-85H?

Any help would be greatly appreciated. I am completely lost.

I am going to try to find a service manual online later. Maybe that will help. But I've had enough for one day. This has been a lot less simple than it should be. I need a break.

If anybody has info on a US seller than can get me the right capacitors quickly, I would really appreciate a point in the right direction.

Thanks

[jimdagys]

Your average TV/vcr that is sitting on the curb to be thrown out is a good source for capacitors/resistors, etc.

[nic2k4]

Digikey is your best source for electronic components on the web. Have you looked in your region for an electronics place? Just go to google maps, center the map around you town and put capacitor in the search bar.

It may not be a good idea to change the value of the caps, but it's all right to go with the next higher voltage rating.

[dafoe]

Just attempted the soldering job tonight. I gave up on the caps and just got the closest match at Radio Shack.

First of all, 25 watts is not hot enough. Or there was something wrong with the iron. When I touched the iron to the desoldering braid nothing happened. Literally. When I watched a youtube video the solder almost instantly melted into a puddle

I waited another 20 minutes for it to "heat up" It never really did get hot enough. I did manage to get the capacitors out and remove the solder. Although I think I may have damaged one of the pads. It was a complete nightmare.

I soldered both capacitors in. But I was too pissed to notice that I had put one in incorrectly. So that blew. I'm going to get another one and see what happens. I don't have very high hopes at this point.

I am however, more determined than ever to master soldering. That experience left a really bad taste in my mouth.

[fzabkar]

Plenty of service manuals here:
http://elektrotanya.com/?q=showresult&what=DMR-E85H&kategoria=&kat2=schematics