8 years later and your still helping people 😍

I replaced a blown 125-volt, 6.3-amp slow-blow fuze in my aging Sony STR-DE597 7.1 receiver and when I powered it up, after a few seconds it went into protect mode every time. I was stumped, but I think you may have told me how to fix it. The info and the lesson are greatly appreciated. If you're still checking this video after 5 years, thank you, NorCal715.

Norcal is one of the top guy in this business such a knowledgeable and professional technician. Following him for years now. Good job my brother. Cheers!

Enjoyed watching the entire video. I like the feeling of success when there's a fixed equipment after a repair..

Thanks for this video. It was a perfect place to start in getting a Sony receiver that I pulled out of a junk pile working. Nothing like checking it after a repair and seeing a unit come right back to life!

@justinberry3991

4 ай бұрын

Keep looking around. That's where mines going

Another great repair video. I have 2 Sony receivers that go into protection mode. Now I am motivated to fix them.

@terrellbuechner7397

4 жыл бұрын

My Sony str de685 display light is not Comeing on the store comes on but the display light don't how do I fixs that

MAN THIS IS A LIFE SAVER!! I HAVE A SONY STR-DH130 RECEIVER !! It is stuck in protect mode and I just so happen to have a solder gun and volt meter I'm going to fix my own receiver ASAP !! NOW I got to order the Transistors !!

Man U are one of the best I’ve seen with explaining how to work these

It's next to impossible to find useful information on this for early 2000's Sony AVR's. Thank you so much! I'm much more confident that I will be able to fix my STR-DE885's center channel now

Absolutely wonderful of you to post a video like this. Much appreciated. We are expected to just throw these out and buy new units, with a little troubleshooting and effort someone could save hundreds in replacement units. I have 3 older units handed down with this same issue, and personally have a

I have an Sony SR-k750P with the same problem. Happened to find your excellent video and sure enough the exact same problem with the same readings even. Ordered replacement transistors off Amazon and will soon be trying the repair. You certainly saved this Receiver from the dump as without schematics I didn;t even no where to begin except looking for the obvious. Thank you for taking them time to share.

@cb3475

7 жыл бұрын

Did it work?

@kikcodog

7 жыл бұрын

Unfortunately, No. It must have been something more.

@BioCybergoth

5 жыл бұрын

@@kikcodog i have the same amp but it got much worse, some problem before, a transistor almost burned, the heat compound got darker and smell very bad, even some smoke got out, but weirdly enough, re solder every transistor, put everything back, power and got sound, but then i tested the headphone connection to find any parasitic signal but suddenly, the screen showed PROTECT but before blinking, the unit went off, the transformer got killed, nothing blow yet, replaced the step down converter to power it up again, relays work but now i have no image on the VFD and i don't know what went wrong here.

I have a Sony reciever str-av570, that keeps going into protect mode intermittently, even when the reciever is off, will intermittently do relay click and amber leds on the front will glow gradually, off, and repeat till I unplug it. Back in 2003-2004(before KZread), I took my reciever to a authorized sony service center that did not know how to fix it, but charged me $35 to inspect device anyways. From this vid you posted, looks like a good place to start. Thanks for sharing!

Excellent video! Always you are posting high quality and knowledge based videos. I know video shooting and editing is a tedious process but by this way we are helping our friends. Great effort. Regards,

@vinaykamble3275

6 жыл бұрын

LearningZone hi. I m vinay I got one receiver. Model ...STR- K870P in protection mode. In cold testing every part normal condition. Problem is after starting Showing PROTECTION. What can I do.

Excellent video. Well explained all details. Nice to see a professional skills to avoid recycling in electronics.

Nicely done Steve; When logic is deployed, troubleshooting becomes easier.

These old sonys have the Vacuum Fluorescent Displays(VFD) that I think look beautiful and don't exist as much on newer receivers making these a very beautiful receiver to continue to keep functioning. Another thing I've been a fan of on Sonys is that they take a signal and can be set to put it back out without effects as clean as the signal they were given except amplified for speakers which is great if your DAC or something is an external device that wants to do it's own effects/has better effects.

Thankyou helped me repair my Sony STR-DH590 same topology just 2 channels less, mirrored you step by step found bad solder joints, Seams to be a sony issue with bad solder due to heating and cooling, but thankyou again.

Why i like this video ? Because you explain the complete diagnostic procedure... And from that i learn alot ! Thanks ! Looking forward for the next one !

@terryfictv

5 жыл бұрын

I recently finished repairing a STR-DE135 with protect on symptom. Upon visual inspection, I saw two obvious issues . The driver IC701 area and the Q801 24v regulator had overheated resulting in bad solder connects and a darkening of the circuit board. IC701 did not test bad but I replaced it and c740,741 and c742. Protect still on. Next I replaced c802. Protect still on. Finally, confident that both circuits were restored to fully operational condition I replaced r740 10 ohm and Shazam ! Solid fix ! The takeaway is overheating is often caused by bad capacitors .

I fixed a doomed STR-DG520 with this tutorial this is gold! 105Ohm is within tolerance tho I found one that read 2MOhm instead of 100

an update on that HK receiver i had that shut off, it was a bad Center channel transistor. After taking it out, it worked! i got sound and it stayed on. Your video here helped me troubleshoot it! I sold it and the guy is gonna replace the bad parts in it.

Your video helped me to fix a dead home theater receiver. THANK YOU!

Absolutely top notch - clear precise how-to. My STR-KS1300 (slimline 5.1 amp) is now showing the exact same thing. This video gives me a great place to start, and by the looks of it might fix it. the Ks1300 was working but noticed I had a different issue, as it takes random amount of button presses to get it to power on but I'd not hear that relay click but it did produce sound. Although now I get protect mode so I could be a different issue. still work checking the components you showed me though.

Great video and I appreciate your knowledge. I did this myself 35 years ago when I started out but it's just not worth the time and effort to repair these things. Often the driver will be failing or you'll have a heat related drift problem and they'll just blow again after a time. Throw it in the junk pile and buy another one. They are all disposible these days. That's just the way it is.

Man, you are an electric surgeon 😷. Ty for this video.

thank you very much . I am an amateur and you helped me a lot with your video to repair a sony str-de595. Good for you

I congratulate you, straight to the problem excellent explanation and proper sequence, and NO drama ... other videos do much theater for something so easy to end up confusing and frightening apprentices, thanks for your videos

Very informative video. You you tube producers are really helping teach people like me....well some of you are. Peace

I have similar Sony Muteki 1510 Watts receiver. It looks same as this unit from inside and outside. But this is 6.2 channel amplifier. I have issue with center channel which have some noise and sound is not clear. Rest all channels are working fine. I did check the center speaker in other channel and speaker is good. I strongly suspect the noise is being introduced in center channel. Please guide me how to troubleshoot this issue. Which all components could be problem?

I have to say that your videos and wonderful instruction have been invaluable to me. I had been reading/studying and doing little "experiments" for several years. Your videos took me to the next level and I am really enjoying repairing now. Thanks again! Just a quick question if you would; I have a Sony receiver that I am working on currently. Power supply is good, power transistors are good, emmitter resistors are good. Something is dragging down the B+ rail voltage by approx 20v then quickly goes into protect mode. I think it is a shorted driver IC. Is it safe for the circuit to take the chip out of circuit to see if the B+ rail normalizes?

Hi there. To start off, I am by no means a repair tech but in an effort to "keep' em out of the recycle bin," I pulled the cover off my Sony str-de705 receiver hoping to trouble shoot the "Protected" message shown in the display. Leaning towards a blown amplifier channel, I desoldered and removed all 6 ic's (3 pairs of companion 2488 and 1620 transistors) and tested them on the bench. All show correct bce diode junctions and no shorts. The 3 emitter resistors also check good. With all 6 ic's removed, I powered the unit on to see an "All clear" message in the display followed by the dreaded "Protected" message once again. I removed, tested, re-greased and reinstalled the 79m12 and 7812t voltage regulator ic's with no change in outcome. I visually inspected the 2 large filter caps and they look fine as do all the nichicon caps in the unit. Several fuses on the mains input board as well as the transformer board all have continuity. With all ic's regreased and reinstalled, the "Protected" message remains. The unit will stay powered up however the speaker (safety?) relay never clicks-in. I checked for bridging of the rear speaker terminals and found none. I am back at square one. If you don't mind my asking, where would you point me toward at this point? Any advice is greatly appreciated!! Thanks for your time. Jim

nice one sir your the best technician i've ever seen your my idol because i learn a lot from you thanks

Thanks so much for making this video and the in depth troubleshooting explanations. I was able to get my Sony STR DN1000 AVR back up and running again thanks to your video. I had no experience with any of this and very little soldering experience. Using a $10 multimeter, I was able to find that I had a bad emitter resistor and a pair of bad output transistors. Ordered some new ones from aliexpress and carefully soldered them in and it powered up! I connected all 5 of my speakers and I found that the front right speaker sounded like it was badly blown. I then moved both front speakers from "Speaker A" to "Speaker B" and the sound is perfect again. I don't know if my "blown" front right speaker when using speaker A is due to poor quality parts from aliexpress, my poor quality soldering job, some other small resistor needing to be replaced, or something else, but I only have 5 speakers in a 7.1 channel receiver, so it's not bothering me.

Excellent Video, Great effort, let us look into actual remedy information rather than extra sounds,

Thank you for explaining how to test a transistor. I've been watching videos and everybody does it but no explanation gees.

I used to be a sparky many years ago, And this sounds like a lot of work. I think Ill just pay the guy to do it. But many thanks for your help. I have the VA555es and it keeps hitt protect, but only if all speakers are plugged in. I know theres no faults with any of my wires or speakers, it just seems having the whole lot in Protect comes on, so many its overload issue. Like all scientific things. Fault finding is the biggest issue. So Ive had it 15 years, maybe its time for a new one!

As a footnote, I did some voltage checks with the unit powered up, looking at the 6 ic's mounted to the main heatsink. Base idle voltage on two of the three 2488's tested at +1.15v and -1.05v on the 1620's. The 2488 collectors tested +52v and 1620's at -52v. Emitter outputs tested at 0v. On the last pair of ic's (nearest the front of the receiver) the 2488 had -51v base, +52v collector and -50v emitter. The 1620 tested at -51v base, -52v collector and -50v emitter. I tripple checked them for shorts and both tested fine with all diode junctions intact. What would allow 50 volts to show on the base side of the transistors other than a short? I believe the base voltages are effectivly "turning on" the transistors and thru-putting 51 volts (less the v drop thru the diodes) ending up as 50v on the emitters. Hmmm.... Again, thanks ahead of time for any help you or your subscribers may be able to lend to my troubleshooting. Reguards, Jim

The best video on repair so far. Thank you very much.

Thanks for all explanations. I need to watch this video again :-)

Thanks! I can't wait go get started on the repair. Do you have any recommendations on a reliable brand or model of receiver/amplifier, based on your experience of repairing them? Are there any to avoid or any that you'd recommend that should hopefully outlast others?

Good job - though have to say I was a little disappointed to find out that it didn't have a Protest mode after all!

This video is exactly what I was looking for, many thanks your videos are great.

Mine is a Sony STR-AV550 and had the speaker wires crossed and activated the PROTECTION mode probably shorted an output transistor ? Good repair presentation!

Best video yet . that's explain and really broke down the process of repairing your receiver...... I ready to buy my pieces and fix my sony and denon receivers.

Thank you very much for your explanations. I hope i can repair my “Protected” Sony STR-DE597.

Simply Lovely. Very impressive explanations reflect the work experience.

I realise this is an old video, but hopefully you're still willing to help me. I'm completely new at this so please excuse my ignorance. Yes, I acknowledge you cannot be held responsible and I do this at my own risk. I'll be very careful. With that out of the way, the case with my receiver is that the tower speakers and one rear speaker is very quiet. The subs seem to work, as well as the centre and the remaining rear speakers. To clarify, are you checking the transistors on the diode range in this order?: Pre-powering on: Positive on collector. Negative on emitter. After powering on and then powering off: Negative on collector. Positive on emitter. When I did this, pre-powering on, positive on collector, negative on emitter I got: About .630 on all the negative transistors and 0 on all the positive transistors. After powering on and then off again, negative on collector. Positive on emitter I got: About .630 on all the positive transistors and 0 on all the negative transistors. Does this sound right or am I completely doing this wrong? I was expecting only the transistors for the non working speakers to be faulty. The emitter resistors all read about 1.3 ohms. Didn't find any spikes in volts when testing the centre lead of the resistors.

I’m still loving this video

Very precise tutorial,Norcal..well done...Question is,do you regret,making this? Having read through most comments,it seems every other comment is,a request for a diagnosis,on every piece of gear,ever made,in every country on the planet....To which I say....Check the obvious,follow these instructions...if that doesn't work..take it to a pro,or give it away and go get another one to destroy...Receivers were simple 40 years ago...today,not so much...thats why techs charge what they do....not everyone is capable.

Having similar problem on STR DH 810 except my display does not come on. I press the power button here a click about 15 seconds later another click, nothing happens. I want to fix it my self if possible, thx for the video.

My Fluke will calibrate the leads when you switch it on and put it on the 40 ohm,diode, continuity location, then hit range, and CAL will come up on the meter,,,then its takes into account the meter leads...Its a Fluke 79III I have...nice video.

Hi! Thank you very much for this video. My Sony STR-KM3 (Argentina model) is turning off right after power on, displaying a "USB FAIL" error message, despite the model DOES NOT having any USB connector? (I have once repaired the same model, but with USB. The problem was a faulty relay (RY901)). Any suggestion or hint? Thank you.

Hello norcal, may i know the model of your soldering iron and its power and which temperature you set it? It seems to solder and unsolder so well.

Another very informative tutorial.Thank you.

Good communicator, well explained fault finding, loved your tip with the dental pick.............Liked, subscribed, and looking for more. Ray H. from the U.K.

I really appreciate this video as I have a STR DE445 that is going into protect mode after working on it. I screwed something up as to start I only had a quiet right channel but everything else seemed OK. I took out all the power transistors and checked them out of circuit which seemed like they were OK did not notice any shorts but after a lousy solder job putting back it together it goes into protect now. I need to take it back apart and do it right checking emitter resistors and transistors properly the way you showed us and maybe I can resurrect it? I really needed your guidance in this video, thanks again for taking the time to produce this it will help me tremendously.

Thank you very informative and to the point.

Love the trick with the dental pic . Thanks for the video.

thank you so much of your very informative videos.

Very good documentary and very informative lecture, love see more.

You really know your stuff, if you were near, I would have you fix mine, but it's a bit much for the average joe.

Great video, thank you! I have an STR-DE597 that goes into Protect mode, but seemingly only when it's cold. Can't wait to get stuck in. Could this also be a reason for almost no bass coming from one side? I have swapped speakers and inputs to no avail.

Like the idea of the stainless steel to clear the hole. I have the same equipment (or very similar) one channel is really weak and shows no protection mode. I do try to test all mosfet and this resistor. But could not find anything I am wondering, could it be a resistor in Th channel, or may be the IC? How can I test the IC? Thank you.. Great video.

Excellent work, this is a very helpful video and the commentary really good -Thanks man!

Thank you, once again another cracking lesson. Keep up the good work

Hi, i have a Sony Hcd-Fxg9k here thats with no power issue for a very long time, probably due to lightning strike. I have sorted out primary and fuse no longer blows out. This unit has 2 STR IC, one is STRF6168 and STRV153. Both has been replaced, electrolytic caps has been replaced, a few smd diodes replaced and resistors replaced. The problem now is, on VCC of STRV153, voltage are fluctuating between 12v to 15v up and down. Theres no voltages at all on any of the output pins. I have checked all the smd components, all seems to be reading accurately. But i know there IS something thats preventing the STRF6168 to start up.

Thanks for a great video on theSony!

you are awesome ...i dont mind the slappppping lips etc dude you just know your stuff

Congratulations, i was very helpful your lesson, thank you very much.

thanks for your response, I have done all of what your said, except the iphone carmera to remote..I try that today, and let you know..I know this remote is old, but it was working just find..I don't know if it can be programed again but I am trying everything to get it back, I appreciate your returning a response to this problem I am having..grateful:

@zoelynnkendrick1708

5 жыл бұрын

I tried the phone to the remote didn't see any light..it failed so I guest I'll get a universal remote and see if that help..again thanks for your help..

I have the protect msg on my HK AVR130, disconnected all spkrs except main R and L and it worked for a few hrs, now I get the protect msg and it shuts down every time. Works fine with Headphone jack. Should I follow the same procedure you have here?

Marvellous work. Any sprays available in market to protect PCBs from moisture and other contaminants place update

Parabéns pelo ótimo vídeo. Vou tentar consertar o meu também, um SRT-DE885 que já está parado há mais de 2 anos pelo mesmo problema. Obrigado. Congratulations for the great video. I will try to fix my receiver too, an SRT- DE885 it is stopped about two years with this same problem. Thank you very much.

appreciated your videos and thanks for the hard work .

Thanks very helpful. What does a repair like this roughly cost in Rands.

@norcal715

2 жыл бұрын

Appropriate repair cost in USD is $125-$175

Hi, thanks for a informative video. I wonder if you could help or point me in the right direction, have a Sony STR-DG910 which has some issues... If you plug it in, you can turn it on using the power button on the front panel, and you can turn it off (standby) from the same power button, but it won’t turn back on again, if your pull the plug out for a second and re-power it, it will allow you to turn it on again, but it goes “dead” again after you put it into standby again.... the IR remote is also non responsive, all functions. I have checked signals with my scope and can are getting all the way onto the “digital board. The front panel knobs work off the same IC, and they respond when the radio is on.... like vol/input/tone etc. so it means that ic must be running. It’s almost like when the chip goes into sleep, it doesn’t want to wake up, unless you remove the power for a short time. Any help would be greatly appreciated. Kind regards

Good day. I followed this video of yours and it's helped me alot, so thank you for that. But what I would like to ask and need some help with is a NAD T743. What it does is that it's stuck in the standby mode. Could you please just gie me an idea of where to start. Regards Cedric

Do you have any suggestions on tracking down popping and crackling sounds coming from only one channel of a Sony Receiver (center to be exact)? Although my Sony amp is not same (has 9.2, with bi-amplification option on the front channels), I'm sure you would have an idea. I followed your process of diagnosing a receiver (this particular problem), and it doesn't seem to be the issue for me (although I realize this amp was in protect mode). Your understanding and explanations are very clear and precise, and I wish you had (if I can request) a video of common receiver/amplifier problems, and your process to diagnosis them (I realize you have a few videos with a few of the problems). Thanks for any help! Btw, I have a STR-Da2800es

An update on my STR-KM7000 I've replaced all of the output transistors because I wasn't 100% sure about them. Unfortunately, I still have the same issue. The tower speakers and one rear surround speaker is still very quiet. The emitter resistors all read 1.3 ohms, which is higher than what you said they'd typically be. Is this strange for my model? What would your next step be in my case? Could this be a case of a damaged driver IC pack? If so, which one? How do I go about testing them?

Hi I have excact same unit, it went into protection mode, I somehow managed to get it to turn back on but missing front left channel. Now have soldering kit so going to check the emittor resistors. My question is, what qualification is required to know how all this works. I am very technical and mechanical, micro solder charge ports and xbox retimer chips etc. Need to learn the diagnostics side and how all these resistors, mosfet and capacitors work properly.

Hy norcal, i have a sony str-de497 av receiver. 10years old one. Now when i turn it on and started to use after some minutes. The input mode change automatically itself with out any other action. What was the reason.? I done the reset function many times but nothing happened. I checked its mother board voltages. There is -30v voltage printed on mother board coming from stand by board ckts. I measured this voltage and it showed -18.5V So by referring service manual there is voltage regulator circuit run by a 2sb734 and two zenor diode volttage rating of 6.8v and 18.8v. From the service manual it showes transistor input volttage is -45. So i measured this volttage it is ok the input voltage is 45 but the out put volatge is only -18.5. So i replaced the transistors and zenor doiodes but no luck. The voltage measurement is 1 volt less than previously i measured. So i replaced all the capacitor and resistors no luck. Problem continued.... please help me to re rectify the problem to solve the issue thanks bro

I have a Sony DA80es with the Protect message problem. While not the same as the one in your video I followed your procedure. There are two emitter resisters showing 24 ohms when power is on and all the rest are very low voltages. But the component that emitter resister connects to has 5 leads on it. The component is a Sony NEP250. Could you tell me how I can check this like you did the transistor on the unit in this video. Thank you!

He's Back!!!!!!! Yeah!!

You are a good teacher sir!! I have a onkyo 646 that has no sound 🔊 where sound look and what should I start trouble shooting? Thanks

Hi, what wattage are the 100ohm base resistors you changed? I found 6 bad transistors and replaced all the base resistors but all of the bases resistors, except for the transistors I changed exploded. I guessing the 0.5w ones I am using might be too low.

I followed this video but everything was in spec. I cleaned a lot of dust and stuff out from the board and that fixed it. Must have been something conducting

I picked up a similar Sony receiver for free on CL. Replaced one of the fuses which was blown and one of my emitter resistors lit up like the 4th of July. I'm going to try and switch it out along w/ the driver transistors. Thanks for the tutorial! Oh, and did I miss where you replaced the 100ohm resistors?

مساء الخير ايها الرائع ....بصراحه لم افهم شيئا ابدا........انت تتكلم بسرعة ر هيبه والتوضيح قليل جدا ..مع انك اكثر من رائع

Very good, clean manutention and correct....

Great Video,I have this same STR-DG720 has been great,all of a sudden the 2 front speakers are very low volume,all others are ok.Even on 2 channel setting,I have to crank volume to like 40 or 50 to get any kind of volume on the 2 front speakers.It's just the 2 front speakers.All others are fine.Have you seen anything like this before on this receiver? Any idea's would be greatly appreciated.The 2 front speakers work,but very low volume.Speakers,wiring,and connections all good.Just noticed this a few days ago.All speaker lights on front panel are lit.Thankyou

Awesome video. Very clear. Are there any steps you take to make sure the filter caps are discharged or is there a discharge circuit on the unit?

Very informative awesome diy video! thanks!!

I have this model Receiver but a slightly different problem and need to know where to start repairing it. I have two 30 watt speakers hooked up to the front speaker output and no matter what input I use I barely get listening volume with the volume maxed. if i change to the center or any of the surround i nearly shred the speakers at 40. any insight would be helpful.

Great explanations and instructions.

Great video. Picked up a STR-GA8ES for $34 at the Goodwill. It "worked" for about 5 min. Never got any sound. Then it blew the main fuse. Tracked it down to a dual power transistor (NEN250). Pulled it out. Put it back together. Now it has the "PROTECTOR" failure. Based on your video I will check the resistor packs and order the transistor. If it works, great receiver to $42. If not I will have to trouble shoot further or turn it into "spare parts." Again, great video, including your soldering/de-soldering techniques. By the way, where did you get the schematic for yours?

Thanks for an informative and interesting video.

Thanks for video. I will try repair my receiver.

Great video!I have the same problem with SONY HT-DDW840. There are five big white noble resistors. When I test the central lead with DC voltage range I get the following readings: 3.383v on four of resistors and 0.52.4v on one of them.Based on this, can I conclude that this fifth one is damaged?

WISH I HAD A BRAIN THAT UNDERSTOOD ALL THIS !

I have this same receiver and am experiencing a problem. I am only running the fronts and a powered sub and it seems as though my full range fronts do not operate with any bass as they once did to my belief whether they are set to large or small. Thanks in advance, Russ

Still waiting on replacement parts (2 sets of new transistors arrived today, both check out as functional using multimeter). The other day, I removed a 100 ohm resistor that was testing out of spec (was still out of spec while not in circuit). Word of warning though - I have an STR-DH130, and there are two SMD components mounted near the holes for the emitter resistor - while I was removing the emitter resistor, I wound up popping a capacitor off without even realizing it (I'm still a noob). I'm pretty sure I toasted the solder pads for it while trying to get it back on (along with the component itself). So had to order some SMD caps as well - not sure if I'll be able to re-mount it without digging down into the traces. I'll get this thing fixed though.

@norcal715

5 жыл бұрын

good luck

@Fedaalis

5 жыл бұрын

@@norcal715 Thanks, and thanks for the video!