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Panasonic SA-HE200 AVR - OVERLOAD

post #1 of 18
Thread Starter 
I have a Panasonic SA-HE200 6.1 AV Receiver (circa 2003) . I think this is the last model before they then went digital and got smaller. It's been on the shelf untouched for years, but we use it any time the plasma is on.

We were watching TV tonight (at normal volume) and all of a sudden the sound went off and OVERLOAD scrolled across the display. I turned it off for a few minutes and when I turned it on it said Overload Turn off receiver. I turned it off for about 10 minutes while I unplugged the surround speakers, the (powered) sub, and the center speaker (just the L/R JBL 26ii speakers and a few components hooked up).

It came on and played fine, but a few minutes later it said Overload again. I unplugged everything and turned it back on about 15 minutes later it still said Overload.

I put it on my workbench and removed the cover. By now it had been un-plugged for about 30 minutes. When I plugged it in it still said Overload (and the fan comes on) with nothing hooked up to it. It was very clean inside. I went ahead and checked the fuses and cable connections inside.

I put it in the other room (with the cover off) and hooked up just the original JBL center to it (and my MP3 player). It played for a while then said Overload and went silent. So, I re-created the problem in a different room (it must be the AMP or the JBL Center). I disconnected the center and then tried a pair of JBL towers from a different system. It played fine. I played it at 0 volume (max) for about 15 minutes straight ... no problems. The main heat-sink inside was almost too hot to touch and the fan turns on for volume settings between 20-0.

So I figured it was the Center speaker overloading it. To make sure I hooked it up as well (3 speakers hooked up now). To my surprise it plays fine now (even at extreme volume all the way up to 0 (it was super loud especially with the JBL towers) . Since the MP3 player is only stereo, I was using the NEO6 settings both ways (center louder then L/R louder). All is fine. It's still playing fairly loud (its been about 60 minutes now with no problems).

Can anyone explain what might be happening or advice on how to proceed troubleshooting?
post #2 of 18
Thread Starter 
It wasn't dirty inside, but went ahead and blew it out and put the cover back on it.

I noticed that the heat-sink compond on the MOSFETs is still moist.

While it played for hours with the cover off (with the 2 JBL towers and 1 center ... at max volume), now with the cover on, it Overloaded it about 10 minutes.

The fan control is strange. It doesn't seem to be controlled by heat. More like total power output or even volume knob setting. When set to a medium loud setting, the fan doesn't come on even though the MOS-FET heat sink and the power transistor on the logic board is too hot to touch.

The fan finally comes on for volume settings 20-0 (max), or after it Overloads ... but by then it's too late.

Looks like it's time for a new amp. I've only owned a couple before this one (an Sansui and a Sony) but they both still work. I replaced them due to technology advances, not because they died. However, this one was driven harder and used more (full time, better and more speakers, louder).
post #3 of 18
Sounds similar to how my panny XR45 died. It shut off, after anywhere between seconds and hours of running, and the fan wasn't turning on at all. The circuit board was dark brown near what looked like the power circuitry and the fan driver. Turning it back on again, it repeated the same behavior.

I've heard that the XR45 fan is controlled only by current load on the power supply, and not thermostatically. Not a bad way to do things, I'd guess.
post #4 of 18
Thread Starter 
By now, the AVR would go into an Overload condition about a second or two after turning it on (when the main output relay would normally click closed ... which wasn't happening ... no output at all).

It turns out the schematics for the Panasonic SA-HE200 are easy to get on the internet.
http://www.eserviceinfo.com/download..._SA-HE200.html

There are 2 large MOSFET power transistor ICs mounted to the main heatsink. The 6 channels are split between them. The chances of both of them going out at the same time are slim (it's probably one or the other). Panasonic made it easy to unsolder them from the bottom of the main board without pulling the board out.

If you compare the voltages on these 2 chips, you should see one with unusual voltages (around the middle) PINS 12,13,15,16. Those deal with the Internal Overload condition of the chip and if ok, giving the ok to turn on the main relay on the speaker outputs.

Pin 10 just helps turn on the fan as needed. Pin 12 of ic601/602 is the real Overload signal. They go to pins 3-4 of ic901 (the main CPU).

In my case, it was IC602 with the weird voltages there. It was also the cooler one to the touch (even in Overload) while IC601 (the other MOSFET of the pair) was hotter.

I know that you can sometimes remove the bad transistor or regulator and it will stop blowing fuses. Keeping that in mind, I removed IC602 and powered it up. Now, instead of immediately going into Overload state, the amp powered up more normally.

I could play my MP3 player into various inputs and the left channel of the headphones work. This is because they split the main L/F channels between the chips. I could change inputs, DSP modes, use the radio tuner, etc.

The main speakers did not work yet, but this is not really surprising because the main speaker output relay doesn’t click on. I think it can tell that one or more channels are down and refuses to activate (which is expected).

So, now I knew a lot of boards were working fine (particularly the Power Supply, Main Logic/DSP board and the main CPU/Display/Control boards). I also tried various inputs (some on the main Power Board) and they all worked properly as well.

I HAD NOT seen Overload since I removed IC602. I tried not to push it too hard because the output it “unbalanced”.

I replaced ic602 with a new one. I had to get it from Canada.
http://www.richtechparts.com/i-1550-RSN310R37A.html

It works great now

Of course, I had to clean off the old and replace the silicone heat sink compound on the new MOSFET, but while I was in there, I also replaced the silicone on the un-blown or still good ic601 MOSFET. I'm glad I did and here is what I noticed. With the old (but still pliable) silicone the front of the MOSFETs themselves would get very hot. When cranked up, the fan would come on but they and the large heatsink would still stay very hot.

With the new silicone on both ... the MOSFET fronts stay cool and all the heat is properly transferred to the heatsink (which still gets really hot). However, now when the fan comes on it cools the heatsink down drastically.

It amazing how much better the thermal management works now with the new silicone. I think that the inability of the old silicone to dissipate the heat from the MOSFETs, might have lead to the premature failure of the one MOSFET. It also seemed to have also kept the heatsink/ fan system from working properly. This turns out to be similar to how old silicone can allow your computer's processor to overheat and even burn-out (even if the fan is still working).

I posted this in case it might help someone one day. However, if you are not familiar with soldering or board level repair of complex electronic equipment, do yourself a favor and get some professional help (or even a friend that knows how). I have seen repairable gear turn into unrepairable junk many times.

As for the silicone, the next time you send in your nice high-end amps for servicing, you might ask them about re-siliconing the power transistors. It's like maintenance on your car. It's all about being pro-active ... before something blows up.

This is as far as I had to take it apart. This picture was taken right after I had taken it apart (old silicone still on all the parts). Don't run it or check voltages without the heatsink installed. I had to move the transformer and PS Board to get to the screws on MOSFET ic601. I reinstalled them temporarily before turning it over for soldering. Silicone it and screw the new MOSFET to the heatsink half before installing it for soldering. Apply the silicone thinly and evenly, but don't get any on the pins (only the metal backing).
LL
post #5 of 18
Thread Starter 
So, before this Panny AVR started giving me troubles, I was thinking of upgrading to something with HDMI capabilities (to get ready for Blu-Ray) and to take advantage of the HDMI ports on my new Panasonic 850 plasma.

When it initally failed (at the request of my wife ... if you can believe that ... surround sound does make a difference ) I installed a new Onkyo 607 AVR. Now that this HE200 is fixed, it goes into the other room.

However, when I was using the speaker calibration features of the Onkyo 607, I found out that the tweeter driver on my nice (but older) JBL center channel speaker was blown. I replaced the tweeter (and the speaker works fine now).

http://www.avsforum.com/avs-vb/showt...2#post16849752

Since both problems appeared at the same time I'm pretty sure that either one or the other caused the other to fail.
post #6 of 18
Thank you so much, Tesla1856!

I've had one of these amps for a couple of years, no problem. I recently bought another one on Ebay for a dollar (they said that it was non-working and displayed 'Overload'). I figured that perhaps I could do a 'Reset' and it might work; for a dollar plus shipping, it was worth a try. Of course, it did not work.

I found this forum and checked the MOSFETs and, sure enough, IC602 is blown. The place you recommended seems to have the lowest price on parts, so I'll order from there and hope to have it working in a week or two.

Thanks again!
post #7 of 18
Thread Starter 
You are welcome. Glad I could help.

Mine is still working fine. I even had it cranked up pretty loud the other day and still no problems what-so-ever. I currently have 5 speakers on that system.

So, you unsoldered/removed MOSFET IC602 ... and turned it on (with very low volume ... for testing only) and no more OVERLOAD condition ... right?

Since one of the MOSFETS is missing, (as I remember) the main speaker relays will not click on, but the headphone jack will work (only one channel of course).

I used GC Electronics - Type Z9 - Heat Sink Compound (Silicone Base). A 1oz. (30ml) tube was around $10 at the local electronics supply.

Good luck with the repair.
post #8 of 18
No, I just checked the voltage levels and found one of the MOSFETs had weird values. I just got it changed out and tested it a few minutes ago and and it works great!

I didn't remove the heat sink or other components. I found that I could remove the MOSFET mounting screws with a long screwdriver, then I moistened a paper towel with solvent and used the screwdriver to push it around to wipe off the old thermal paste. Put new paste on the MOSFET, used some needle nose pliers to work it into position, then checked that all the pins fell through the holes. Put the screws back in, flipped it over and soldered the pins.

Thanks again!
post #9 of 18
Thread Starter 
Quote:
Originally Posted by steve45 View Post

I just got it changed out and tested it a few minutes ago and and it works great!

Excellent. Good work!
post #10 of 18
It's satisfying to be able to find and fix the problem, isn't it?

My SA-HE200 is still going strong although it only pulls 2-channel duty these days. When my wife's choice of armoire arrived on the scene, the receiver wouldn't fit, so I ordered an SA-XR70. As I was unboxing it I could hear something rattling around inside... inspection revealed that one surface mount component had come completely loose, and another one was attached only at one end.

Using a fine-tip soldering iron, tweezers and a magnifying glass I was able to reattach the components. The unit has been running fine ever since.

Somehow I feel as though I got off easy, compared to what you guys were up against. Nice job!
post #11 of 18
Thread Starter 
Greggie,

Nice catch on that lose part.

Yes, in today's disposable society, it nice to keep the old gear working and out of the landfill. We gotta keep our soldering and schematic reading skills sharp somehow, right?

I've done some SMD lately ... yes, time to break out the magnifying glass. The hot air soldering is interesting, but I miss the days when everything was hole-through.

The HE-200 was the last of the big/heavy hybrid amp Panny AVRs. Lots of power for 6.1 good-sized speakers and digital inputs. Too bad they appear to be getting out of the dedicated AVR business. At least they are still making nice plasmas.
post #12 of 18
Great big thank you Tesla1856,
about 11 months ago I got the overload warning on my Panasonic SA-HE200. I took it into a local Panasonic repair shop and they fixed it. It was the left Mosfet and they charged me $161.00 CAD to install and it took them 5 weeks from when I first took it in until I was able to pick it up. Well just last week I got the overload again! As I didn't want to in vest another $160.00 or so I decided to look to google. I found this very helpful thread. I ordered a Mosfet from the link you provided. It arrived in a day and I bought a voltage tester for $10. I was not really able to find the unusual voltage you were talking about but I could tell from touch that IC602 was cooler to the touch. So I went about replacing the Mosfet. I haven't plugged everything back into the 5.1 surround but so far the two stereo speakers are playing just great and I'm only out $40 and a couple hours of my time. Thank you for the great info.

Infernovideo
post #13 of 18
Thread Starter 
Quote:
Originally Posted by infernovideo View Post

Great big thank you Tesla1856,
about 11 months ago I got the overload warning on my Panasonic SA-HE200. I took it into a local Panasonic repair shop and they fixed it. It was the left Mosfet and they charged me $161.00 CAD to install and it took them 5 weeks from when I first took it in until I was able to pick it up. Well just last week I got the overload again! As I didn't want to in vest another $160.00 or so I decided to look to google. I found this very helpful thread. I ordered a Mosfet from the link you provided. It arrived in a day and I bought a voltage tester for $10. I was not really able to find the unusual voltage you were talking about but I could tell from touch that IC602 was cooler to the touch. So I went about replacing the Mosfet. I haven't plugged everything back into the 5.1 surround but so far the two stereo speakers are playing just great and I'm only out $40 and a couple hours of my time. Thank you for the great info.

Infernovideo

You are welcome.

I hope it turns out to be completely repaired. Hopefully, you used the thermal compound. This helps transfer the heat from the MOSFETs to the heatsink. In seems that keeping these cool helps keep this amp alive.

Mine is still working.

More fellow SA-HE200 owners and their repair success stories are here:

http://www.electronicspoint.com/pana...x-t220907.html
post #14 of 18
My experience is similar to others who have posted already. OVERLOAD condition displayed on display around 6/2010.

One: replaced heat sink compound with new/clean compound. Result: Worked for about 2 weeks, then OVERLOAD.

Two: removed heat sink, cleaned up goo, powered on unit, feeling with fingers which MOSFET was heating up first: IC602. Ordered 2 replacement RSN310R37A amps, and replaced IC602. Re-assembled everything, and worked fine.

Three: 8/26/2010 OVERLOAD appeared again. Pulled up Tesla1856 directions, and looked at voltages on pin 12 for both IC601/IC602 with the idea of testing which amp was raising the overload signal. After letting unit rest for 10 minutes unplugged, it took about a minute for OVERLOAD to appear; lots of time to measure voltages on pin 12. I was getting -1.5v for both MOSFET amps. OVERLOAD is now displayed, and IC601 pin 12 is -3.0v, IC602 still -1.5v, so I figured was worth the effort to replace IC601. After this was done, works again! Since this was Labor Day weekend, left unit on for about 48 hours and everything worked fine. Given my previous experience, I'm not declaring victory until 1/2012.

Four: I get home on 9/6 and am told the receiver is broken again. ( However, this time the error was F70. After sleeping on this, I suspected F70 meant a bad fuse. Google confirmed this. So... I open up the SA-HE200, test the fuses with a continuity tester (yes removed from fuse holder first), and they are all good. Hmm... However, I noticed the 2A fuse holder had one "loose" connector. By loose, I mean the solder pin for the fuse holder wasn't fully soldered to the board. I was able to wiggle the clip from the pin on the back side of the PC board! Must have been a cold solder joint during manufacturer, or heat shock over the years weakened a poor solder joint. After touching up this loose connection, the receiver works fine again. That was this morning, so I'm still not declaring victory until at least 1/2012, maybe 3/2012.

Comments:
-Awesome thread. Perfect information for anyone with electronics repair skills.

-My SA-HE200 has break-away grills covering the pins to IC601/IC602 on the bottom of the unit. Too bad they don't unscrew somehow. I'll solder these back on someday.

-Removal of IC601/IC602 is easy; use Chip Quik (Google: Chip Quik). This is intended for removal of SMD chips, but works great on these 24-pin MOSFET amps.

-You need a really long Phillips head screw driver to unscrew IC602. Obviously removal of the DSP board isn't an option.

-It is possible to remove IC601 without removing the heat sink. Unscrew 4 main transformer retaining screws, lift/slide back/unplug transformer from 2-pin socket, set aside and just unscrew IC601. With a jeweler's screwdriver you can then pry off IC601 and clean up heat sink compound with rubbing alcohol and paper towels.

-Replacing IC601 didn't require removal of heat sink. "Solder bridged" all 24 pins of IC601 with Chip Quik, then heated everything once more with soldering iron and was able to gently wiggle out the MOSFET amp. Then used solder sucker and soldering iron (with lots of paper towels to clean excess solder from tip) to clean up all 24 donut holes. Put clean coat of heat sink compound on back of new IC601 and opposing side of heat sink (not too much though) fit 24 pins through PC board, and then screwed MOSFET to heat sink. After screwed in, soldered all 24 pins.

Hopefully this is the last time I'll crack the case on this receiver for a long time. Should this break again, it is probably time to replace the unit. It is near 10 years old, and although it still works and sounds great, it is getting a little dated. At some point, having HDMI switching will be a nice to have feature.
post #15 of 18
Thread Starter 
Good to hear it all worked out.

Thanks for taking the time to share more detailed info about this repair.

Nice find on the fuse holder. That was a common error code back-in-the-day ... I wonder how many times it was the holder and not the fuse? Cold and/or weak solder joints are more common than people think ... especially in high voltage/amps circuits ... like power supplies.

The MOSFET "break-away" grills on the bottom ... they snap off, but you flip them over or something and they tab-in and screw back on with a short self-tapping sheet metal screw. The little hole is pre-drilled ... just make sure to use a nice short one so it doesn't touch the board.

Mine is still working. I gave it a nice workout the other day.

Keeping these amps (any AVR or amps) cool thru-out their lives is a good way to help them last.
post #16 of 18
Thread Starter 

Panasonic SA-HE200k is still going strong and working fine.

 

Foam surrounds came lose on my Boston speakers (so I re-glued them) ... anyway, I was working in this (secondary listening) room. Took a close look (and listen) at whole system.

 

As we know, the fan on the Panny doesn't come on until the volume setting is up pretty high. This is a small room so the volume is usually on medium ... therefore, it runs pretty hot most of the time (rear built-in rear fan stays off).

 

I added a old 92mm 12v PC fan to the top grill (outside) above the main heatsink fins. It's powered by a old 6v DC output wall wart. That runs it plenty fast and quieter than full speed. Power comes from Switched AC Output on back of amp so it comes on when amp is turned on. With the volume off, you can barely hear it from 6ft away. Double-sided foam tape holds it in place and dampens micro-vibrations.

 

If unsure about the speed, you could also use an variable DC output AC Adapter if you have one. The AV cooler shops also sell nicer speed and temp controls ... but I was going for a $0 cost solution here.

 

Its surprising how little air-flow is required to change "too-hot" to "luke-warm".


Edited by Tesla1856 - 9/12/12 at 11:12pm
post #17 of 18
Friend brought me one of these to look at, he picked it up for $20. He had done some of the research about this component before bringing it to me.

I've got it apart, metered and heat checked the internals. He too has the problem with one MOSFET.

For $33 each and some time and labor will see if he wants me to repair it.

Thanks much to all of you for making even the possibility of repairing this happen.

Will keep yall posted,
Bud
post #18 of 18
Thread Starter 
Quote:
Originally Posted by Bud Eveland View Post

Friend brought me one of these to look at, he picked it up for $20. He had done some of the research about this component before bringing it to me.

I've got it apart, metered and heat checked the internals. He too has the problem with one MOSFET.

For $33 each and some time and labor will see if he wants me to repair it.

Thanks much to all of you for making even the possibility of repairing this happen.

Will keep yall posted,
Bud

Welcome to the forum.

 

Mine is still working fine. It works well for me because "Workout room" is older gear with no HDMI on plasma or other main gear. Even HTPC is able to use VGA and SPDIF. The Harmony 650 works out the more complicated switching.

 

If you need HDMI, I think you can pick up a cheap 5.1 AVR for around $150. And not my first choice, but you could even go HTiB if you need some speakers also and the room is small. Personally, I prefer "real" components. Onkyo has some nice HTiB that are almost full AVRs (but HTiB packages get pricey).

 

Read thread carefully and good luck.

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