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protection

  1. C

    Kenwood KR-8050 Triggering Protect

    Hey all, I’ve had a KR-8050 that I had rebuilt the left channel in and got back going a while back. Replaced the outputs that were blown while somebody was trying to adjust bias themselves and shorted one. It was working fine for two - three weeks and now increased volume on the left...
  2. C

    Sansui 9090DB Output Problems

    Been through this 9090DB, just finished pinning and recapping the dolby board that was previously preventing sound from passing through the pre in either channel. After the pinning all modes seem to work except for one channel in rec 2 that I plan on addressing later - but importantly - off -...
  3. C

    Pioneer SX-780 Voltage Regulator Trouble

    Hey all, I have an SX-780 that refuses to come out of protect. PA3001 isn't getting the 13.5 volts it needs to come out of protect, but there are more issues. Q25 - 2SD712 7.6v on emitter 7.2v on base 8v on collector Q13 - 2SD325R 25v on emitter 28v on base 25v on emitter C316 has the...
    • CaseyWKC
    • Thread
    • 2sd712 pioneer protection protection board regulators sx 780 voltage
    • Replies: 62
    • Forum: Pioneer Audio
  4. R

    NAD C315BEE Protection at about 1/4 Volume

    Need Help with NAD C315BEE Protection This amp goes into protection when I adjust volume to 1/4 to 1/2 full, with input of 1kHz sinewave at 2 Vp-p. Output offsets are less than 10mV and output is a clean sinewave. With no input I can go full volume without a protection kicking in. Tried with...
  5. T

    Sansui QRX 6001 Protection Circuit

    I was given this unit that had no output, so I started with the basics. I was stuck in protection mode with no relay click. I did some research and learned that if I remove the front and read boards and the relay clicked, it wasn't the protection circuit that was acting up. I then proceeded...
    • TinCanAlley
    • Thread
    • protection sansui 6001
    • Replies: 0
    • Forum: DIY
  6. dlucy

    Harman Kardon AVR series training for protection circuit feature

    A training doc from HK on protection circuit in the AVR series of receivers
    • dlucy
    • Thread
    • avr harman kardon protection
    • Replies: 0
    • Forum: Solid State
  7. mstap42

    Marantz SR-48mk2 Receiver - Power cycles off and on

    Greetings, Someone gave me a Marantz SR-48mk2 receiver. A protection relay or something had begun cycling the power off and back on in shorter and shorter intervals until it finally stayed off. Idk whether it is the power protection or speakers protection. A respected local electronics repair...
    • mstap42
    • Thread
    • marantz power supply issues protection relay
    • Replies: 2
    • Forum: Solid State
  8. JonLewis

    Over protective Yamaha M-70

    Picked up a nice exterior condition M70, but in protection mode. I need to go through the M-70 threads and get my bearings, but this unit will be familiar to some already. First step was trying the DBT to verify protection. Consistent bright150w bulb, no clicks heard from the relays. I'm...
    • JonLewis
    • Thread
    • amplifier m70 protection yamaha
    • Replies: 65
    • Forum: Yamaha
  9. Phobosx

    Toshiba SA-775 Output problems

    I have an old Toshiba SA-775 here I was hoping to fix. The unit would not come out of protection, but no fuses were blown. Initially, I found that Q 601 & Q603 were shorted. I remove them and then the system played through the good channel. I ordered some MJE21194 & MJE21193 to replace them...
  10. foo.kamikaze

    Pioneer SX-727: Protection Mystery Caused by Power Supply?

    Hi folks, I have an elusive and mysterious protection issue I believe originates from the power supply. HISTORY I bought a working Pioneer SX-727 up until I decided to begin rebuilding. I did my research on Audiokarma as I always do before jumping into a rebuild. The first day of the rebuild I...
  11. R

    Sansui BA-3000 No Power

    Greetings everyone, I have a Sansui BA-3000 I bought with issues. I tested it and realized that the RL02 relay was not functioning and decided to replace both relays on the (F-2511) protection board. I then realized the cermet resistors (R01 and R02) were burned up. I replaced them and the new...
    • Rasmu004
    • Thread
    • ba 3000 ca3000 help no audio no lights no power protection relay sansui transistor
    • Replies: 4
    • Forum: Exclusively Sansui
  12. secondmouse

    Sansui 4000 LED re-lamp...just one issue

    Finally getting around to re-lamping my 4000. Several lights are out. This unit suffered some kind of surge in the past, evidenced by a partly melted plug, but does work just fine in all respects. LED kit from Joe is on the way, but doesn't include the protection bulb, and finding an original...
  13. DoctorJon

    Question about protecting my stereo with a surge protecter.

    Hi all, I have a question about how you protect your home from a stereo that is older from burning out when you are unexpecting it. I have a Pioneer SX-3700 reciever that I want to protect both from a surge and the chance that it would have heat sink problem that would result in electrical...
  14. N

    SX-890 Bias and Protection Issue

    Trying to wrap up a refurb of an SX-890 and can't get one channel to bias (DC Balance) and it won't get out of protection. At one point it would get out of protection but wasn't stable on on either channel when trying to DC Balance At this point, on the Right Channel I get ~ -35V at pin 12 and...
  15. audio_exp

    Sansui G-8000 tripping protection too soon?

    I have a G-8000 that’s working fine except protect issue. It was recently re-capped and sounds fine but when you turn up the volume it trips the protection. Bias (16mV DC) & Offset (0mV DC) are perfect. I just have a small pair of 8 ohm KEF C20’s connected. Not sure where to go from here but I...
  16. OskarBas1

    Help! Yamaha M70 protektion problem

    Hello! I've recently recapped my m70 and changed trimpots and some other parts. I was going to adjust everything today and things worked out great but wen I was setting the meter lights i encountered a problem. I used a 8ohm 300w resistor as a load starting with the right chanel, I'm putting in...
    • OskarBas1
    • Thread
    • m70 protect mode protection recap yamaha
    • Replies: 14
    • Forum: Yamaha
  17. Wray & Ting

    Optonica SM-3636 protection mode

    This is a happier thread than I thought I was going to be starting when I woke up this morning. My Optonica SM-3636 that I've owned for about 3 years went into protection mode while idle last week. For several months leading up to that, it had been intermittently emitting very loud bursts of...
  18. P

    SX-727 Protection Unit AWM-027 and Fly-back diode

    I just solved an issue on the Protection Unit and would like to add a fly-back diode as well to that board like I have on the AWM-025. Would you recommend it as well and if yes, is this the correct position? 1N4004 as fly-back diode added between pins 14 (anode +) and 15 (cathode -)
    • pa_200
    • Thread
    • awm-027 fly-back protection sx-727
    • Replies: 3
    • Forum: Pioneer Audio
  19. Ray66

    SX980 with PA3004 chip PCB substitute

    An SX980 that I’m restoring has a problem with the protection board where the relay does not energize. I believe the problem is with the PA3004 IC so went ahead and replaced the it with the ‘substitute PCB’ designed by merlynski and alexhastings (see PA3004 chip PCB substitute). A big thanks to...
    • Ray66
    • Thread
    • pa3004 pioneer protection protection circuit
    • Replies: 33
    • Forum: Pioneer Audio
  20. goldswimmerb

    G-8000 protection circuit question

    I was looking at the schematic and wanted to ask if anyone with more experience in circuit design knew the answer to this. What are C35/C36 for in the protector circuit? They appear to go from ground to the amps output, through a resistor. Bipolar implies that Sansui expects + and - DC voltages...
  21. sean sweeney

    Pioneer SA-9500 ii rebuild protect thump fix!

    I've been dealing with this 9500ii thumping ever since I rebuilt the amp and recapped, from the protect circuit (also rebuilt with upgraded caps and transistors)! It seems the more efficient newer transistors in the protect circuit were staying on too long at shut down and coming on instantly...
    • sean sweeney
    • Thread
    • circuit fix modification pioneer protection sa-9500ii thump
    • Replies: 4
    • Forum: Pioneer Audio
  22. Ray122

    Testing Protection Mode

    So this might be a bit of an odd question seeing as there doesn't seem to be too many posts about it. Naturally lot of post have been about getting amplifiers out of protection mode, but what if I wanted to get my amplifier in to protection mode. Crazy right? This question primarily centers...
    • Ray122
    • Thread
    • amplifers diy pioneer pioneer spec 4 protection protection board protection circuit protection circuit issues spec 4
    • Replies: 5
    • Forum: DIY
  23. B

    Onkyo M-508 wierdness

    Hi Guys & Gals, I have an Onkyo M-508 that I'm trying to fix. Symptoms are it will come up in Protection mode, then switch to Play mode, and then about a minute later, go back into Protection and stay there. I've pulled all 8 of the power supply caps, and on average, they are about 12% below...
  24. zastin17

    Au-666 Protection Block 1RC5 Replacement Diodes??

    I am just about done rebuilding a Sansui Au666. I have replaced almost every single Transitor! Including the Outputs. This thing has a terrible failure at some point!!! I was battling some strange DC wonkyness on the output. Common to both channels. Turns out, 1x IRC5 Diode ""thing"" is...
  25. D

    Sansui AU717 dropping left channel after rebuild

    Hi All, I restored my all original Au717 last year following Leestereo's guide and parts list. Before doing this, the channel would drop and would only come back on if I quickly turned the volume knob higher. I thought cleaning all the switches and pots along with the rebuild would have fixed...
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