Jump to content

Luckiestmanalive

Members
  • Content Count

    1,232
  • Joined

  • Last visited

Community Reputation

38 Neutral

About Luckiestmanalive

  • Rank
    1000+ Post Club

Profile Fields

  • Location
    Sydney
  • Country
    Australia

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. OK, so I received the bag of shiny, new capacitors on three days ago, on Thursday. They are all tested to be within +/-5%. That night, I desoldered all the old capacitors and removed them and soldered all the new ones in their place. The old crossover board has thick metal tracks - ideal for people with little or no soldering experience. I hooked them up and tested them and everything is as it should be. Both tweeters are working together and the timbre and soundstage are more distinct. I'm very happy with how they sound. I've posted a pic of the new caps and one speaker and I'm going to continue to evaluate them for a week or so. The missus isn't pleased having them take up more floor space in front of my regular loudspeakers so I will eventually will have to find a new home for them, I guess.
  2. That's very kind, sir! I'll check out the cost of a fix and then weigh up that vs the replacement options you've suggested.
  3. If it isn't the DSP chip then I'd love any suggestions about where to look next. I can confirm that there is no sound when it is in pure direct mode.
  4. Thanks, very much, BB! I've read that no sound even in pure direct is still consistent with a brokearse DSP chip. If I hit the option button it shows there is no audio signal. I will take a look at those service options, for sure.
  5. Or perhaps you can get the DSP chip here: https://www.aliexpress.com/item/4000626992696.html The IC part number is D80YK113DPTP4
  6. After more trawling through the interweb, it looks like it could be a problem with the DSP chip. I found the bad news from this thread: https://forums.whirlpool.net.au/archive/2780214 This DSP chip doesn't appear to be very reliable, a weak link in the design and something you might want to account of if you are thinking of buying a used AV receiver. I've seen both Onkyo and Yamaha have them. Some have been failing within 3 years. There is no permanent fix - you can heat the chip using a halogen lamp or something else but this is a temporary fix only which may last a week or a few years. If these options don't work it basically junks your AV receiver unless you can still get a replacement chip (perhaps here: https://www.alibaba.com/product-detail/Brand-New-IC-parts-D80YK113DPTP400_62358897818.html?spm=a2700.7724857.normalList.2.167f1e55RLBHYp) and you have an air station to do the replacement. I've tried to heat the chip with a hair dryer (I don't have a halogen lamp) and ran my (dry) soldering iron along the pins of the chip but neither worked. The video and switching works fine so it could be a very heavy digital and analog preamplifier but I don't really need one of those!
  7. I'm stumped with this one so I'm hoping someone here has some experience with this problem and can steer me in the right direction. I have a Yamaha RX-V765 AV receiver that stopped doing audio altogether some time ago! It won't do analog or digital audio at all. It powers up fine and I can hear relay switches activating after I do. I have set up the speakers (just front and left at the moment) and tried the test signal and radio and no sound is making it to the power amplifier. I can tell because on HDMI1, the signal info available using the option button shows no audio signal (video signal info is fine). I have done a factory reset using advanced settings and changed the impedance from 6 to 8 ohms and back again. The speakers are KEF concertos, which are 8 ohm speakers. I've tried changing the speaker connections to surround. Still nothing. I've looked at the boards and can't find any sign of damage from scorch marks or capacitor failure. I would prefer to fix rather than junk it but I'm fresh out of ideas, even after a day and a half trawling through google search results. I'd be grateful if you have any fresh ideas.
  8. For good measure, I also stuck a thin layer of paper tape around the edge of the bare metal spindle platter and added a drop of oil to the spindle bearing. It operates completely silently now.
  9. I've been on a kick of fixing things in my spare time while in isolation. A friend dropped around a Harman Kardon HD7125 CD player that wouldn't read CDs. So I turned it on and put a CD in and the player accepted the CD fine, but then there is some friction sounding noises (briefly) before they stop and the display shows no error and no CD index so it won't play. I turned it off, took the top off (just a matter of unscrewing some phillips head screws) and turned it on. The laser mechanism bobbed up and down, trying to focus on the CD, which was missing, and gave up. I recorded a video on my phone of the laser to check I could see a faint red light, which it did. This suggests the laser wasn't the problem. Don't look directly into the laser or it could damage your eyesight! Then I tried again with a CD. I could watch the CD get drawn in and the laser bob up and down and then the friction noise I heard the first time but the CD did not spin at all. It sounded like the motor for the spindle was trying to spin the CD but something was preventing it. If you google this sort of problem you will hopefully find a link to this thread on audiokarma: https://audiokarma.org/forums/index.php?threads/troubleshooting-cd-players.440522/ This is a good place to arrive at to understand how a CD player works and for troubleshooting any problems you experience. However, the quick diagnosis on this and other threads I found is that the motor that spins the CD is shot and you need to replace it! My advice to anyone else is to check some other things out first. I unscrewed the two screws that fasten the bracket that sits over the CD (shown in the pic below with the yellow laser sticker) as this was where the friction sounds appeared to be coming from. The circular bit in the centre of the bracket (shown in the pic) holds magnets that attract the motor spindle that holds the CD from below. Examining it with the bracket removed revealed that it was stuck. I'd thought it was odd that other youtube videos showed this bit of the bracket rotating while this one did not. The CD player had obviously sat for sometime without being used and there is a thin rubber strip you can get to from the top that must have stuck it to the bracket. So I added a little silicone lubricant around the rubber strip and put the bracket back. I turned the player back on and inserted a CD into the tray and the player accepted and read it perfectly! It is playing a CD right now without fault. Job done then. I hope anyone else with a similar transport mechanism (I'm not sure if HK made their own or sourced them from another manufacturer) and problem can find this post and fix it just as easily as I did!
  10. An update on this restoration. While it went well for a few weeks, it fell off the bed and developed a clicking noise so I ordered a proper replacement belt from turntableneedle.com and swapped out the old one a few weeks ago. This didn't go well and it stopped working correctly so I put it aside until I could get enough courage to look at it properly, which required desoldering a handful of wires to separate the electronics from the mechanical board to get better access. I'm a tinkerer and a newb when it comes to going this deep into electrical circuitry. But I sucked up my doubts and got stuck in yesterday. Having nowhere to go during these times means this became a good use of my spare time. I figured I couldn't make it any worse, seeing is wasn't going anyway. And it turned out more than fine - I got it going better than before = so much so that there is no wow and only a tiny amount of flutter most people wouldn't notice. I am so happy I spent the hour or so it took to complete the job. I hope my story helps you. Here are some tips I learned from this experience. Tip 1: take plenty of pics of what you are doing. I split the desoldering into logical groups, took a pic of the wires I was desoldering and gathered the loose wires together with a little sellotape. When I was done, I simply resoldered them in the reverse order using the pics for guidance. I am not an experienced solderer and the wires are tiny but even I managed to do it ok! Tip 2: have the service manual handy. It showed my main problem was that I had somehow managed to install the belt incorrectly(!), which meant the wheels were going backwards! This was an easy fix. Everything worked fine once the belt was looped the other way around the motor pulley. The much better access allowed me to ensure the belt was not twisted in any way. Tip 3: have some felt tape or similar to tidy the wiring. The old felt tape was not sticky enough after I removed it to get the wires out and they were a pain to keep them still when putting the unit back together. Tip 4: don't despair if something goes wrong. Put it to one side and go back to it later. If you get stuck, do more research about the problem (including posting here and on other forums) and don't think about it for a while. This time helps you dispose of the baggage that came with the early frustration. Coming back to it fresh helps you diagnose and fix the problem. This might take several attempts - again, this is ok. Hope is both your friend and your enemy. You need hope to attempt a job but it results in frustration when it doesn't turn out as well as you hoped.
  11. That's awesome advice, Peter - thanks! I'm looking forward to rejuvenating the crossover boards. I might leave the speaker wiring and binding posts for another time. That project will come around soon enough and I'd like there to be another tweak to evaluate!
  12. I switched the crossovers between the cabinets, played my frequency sweep and found that the MIA tweeter has also switched cabinets so that narrows it down to the crossover board. So I've ordered replacement capacitors from Falcon Acoustics - all done for $60 airmail delivered. My Audio Physic Sparks are back from the Speaker Hospital so I'm no longer bothered about waiting. I'm back to listen to some music now! I will come back to this thread to provide an update on how the capacitor replacement goes.
  13. Thanks, guys. VA - thanks, yes, of course the 7uf capacitor is on the MF circuit. I could do a whole bunch of replacements and hope that fixed it but the freight times at the moment are iffy and I don't want to spend too much right now. mbz - I haven't ruled out a loose connection between the crossover board and the connector socket. I can't see any loose connections and I've refreshed the solder on the components that matter. Also, the multimeter reads a connection (0.4-0.6 amps) between components that connect the HF+ and HF- on both crossover boards. I don't want to experiment with my expensive amp (Plinius 9200) in case I blow it up. This project isn't worth that risk!
  14. Reading over some old threads it looks like I should replace the offending 7uf capacitor and Zaphod has recommended a film capacitor as a replacement that should be an improvement. I've found a few 7uf film capacitors that fit the bill and settled on a kemet 7uf 650V +/-5% tolerance radial box capacitor: https://au.element14.com/kemet/c4aqcbu4700a1yj/cap-7-f-650v-5-pp-radial/dp/2846428 It looks like it will fit the existing space almost perfectly albeit a little taller than before (double the height at 28mm). I will order 2 and replace the same capacitor on the other board at the same time (after doing an AB test first, of course). Would anyone suggest something better?
  15. OK. So I went mad with the multimeter and soldering iron on the offending crossover board. I refreshed the solder at points where I wasn't getting a good reading from the multimeter. Then I checked the readings between soldering points and the connection points where they were on the same trace. I was getting 0.4 ohms everywhere I tested. Then I tested the + and - connections at the bottom of the board. On the good board, I was getting no reading from any of them. On the other board, I was getting no reading from all but the MF connection. It was reading 3.4 ohms. This corresponds to the reading I got across the capacitor on the bottom right of the pic above. I got no reading from the corresponding capacitor on the good board. Have I found the problem or just another one? I mean, the problem I have located seems to stem from the MF circuit when it is the HF circuit that is somehow not moving the tweeter? The HF problem could still reside in a lack of connection between the PCB and the socket it slots into.
  • Classifieds Statistics


    Currently Active Ads

    Total Sales (Since 2018)

    Total Sales Value (Last 14 Days)

    Total Ads Value (Since March 2020)
×
×
  • Create New...