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Hello there, I'm not sure if I mention anything about navigating the wires?, can't 'recall. Nonetheless, I'll make mention of something that may help. Make or buy some wire identifiers, i.e. wire labels and label the wires needing removal in whatever sequence that works for you. Usually if the posts on the board/s are marked 1,2,3,4 etc., then you want the wire labels to correspond with their designated post / termination. Then, if you have a wire wrapping / unwrapping tool/s you could neatly start unwrapping selected marked wires and "liberate" the board from them if you prefer or need to. I'm not going to address the specific use of wire wrapping tools, as I'm sure there are plenty of how to videos on that topic. So, as you can see, it's as straight-forward as labeling your wires to "MATCH" their termination points so you know where to return them. Another side note before I move to the finish line: You may need a few different sizes of wire wrap / unwrap tools based on the wire size of course, so, just something to keep in mind and no big deal otherwise. In fact, you technically don't need wire wrap tools. Sometimes I just carefully "untwirl" the wire from around the post to loosen and remove it. If you do it that way, just make sure the wires are long enough to provide some slack, so you can re-strip and re-twist a new connection point as needed. Sometimes you'll break the old coil of wire as you try to untwist it. Additionally you may need to heat up / de-solder some of the wire wrapped terminals that have been soldered upon during previous repairs etc. As far as getting the wires back on, just re-wrap them on the posts neatly. Again just find some information on using a wire tool (easy enough) and then re-secure good "bomb proof" connections of the wires and posts. A lot of times you can just re-twist the wire around any type of shaft, i.e. a small punch, or my spring hook that gradually tapers from smaller to larger, so I can "eye-ball" an inner diameter slightly bigger than the post diameter. Then you can just push the coil over the post and neatly solder the joint (fill in the gaps between the coils and post) and establish another secure connection. So, there's enough info to hopefully get you going / thinking about what technique/s you want to work with. Lastly, and in some cases, if you can get creative with circuit board positioning / securing, you can carefully gain access to needed components and work on boards without having to remove all the resident wiring. You just need to be aware and careful not twist the wiring around too many times and too aggressively. If wires start popping off and you don't know where they go, things will get a bit more time consuming, so, you may still opt to mark the wires, in case of a "pop loose event", or just be very careful / attentive when moving boards with attached wiring. Again, hope this helps, my best to you.

@@retroelectrotech Thank you for informing me. Must admit, did know about this tool. I will do the labels and take lots of pictures, and try to replace parts without the tool. If not working I will invest in the tool. Thanks again.

Yes indeed they are nice solidly built amps that mean business, and the big "dancing" meters are a thing of beauty. Thanks for chiming in and keep enjoying that 508!

Hello there, the simple explanation is that the right and left source / signal information is being combined / summed together (when in mono) and your hearing the result of that from both speakers because the main amp sections (both right and left sides) are working fine and are not the problem. So the problem is before the main amp section in other words. Without me being able to examine the unit on the bench I can't narrow down the problem of course, however, I would suggest you check the selector / mode switch contacts as well as the mono switch itself. More than likely it's a connection issue involving one or both switches due to dirty / tarnished contact points. I'd start with giving them a thorough cleaning with contact cleaner while "exercising" the switches over and over again. Check for loose wiring and bad solder joints as well. While you're at it, clean and exercise all the switches and potentiometers. beyond that, I can't really walk you through diagnostics over the net / in a comment section / via email due to the lengthiness of it all. But again, do check all of your wiring / connections as needed from the CD inputs to the selector switch, as well as the mono / stereo switch and make sure everything (all switches / controls) are flush cleaned and thoroughly worked / exercised as I mentioned. I hope this helps you out.

@@retroelectrotech Thank you for taking the time to answer with great advices. Ill give it a go and tell you!

I didn't progress any further on that unit following the video. Sometimes that's how it works out with customer equipment. So, I don't have that information available, sorry. I'm sure if you search for a "belt kit" via make and model you'll come up with some options for belts. As far as the idler tire you are seeking to replace, you may not necessarily find a replacement that cross references to that make and model, however, if that proves to be the case, you can take measurements of the tire (using a dial caliper for example) and make some comparisons against some other idler tire offerings available. It takes some hunting around at times.

very true when it's customer equipment and there's bills to pay / lights to keep on, have a fine day, thanks for chiming in.

I'm sure you'll get a lot of enjoyment out of it, take care and thanks for chiming in.

Good to hear they're getting some enjoyment out of it 🙂

No offense taken, There were a few things I did off camera, cleaning the relay contacts was one of them, and yes sir I forgot to mention it, which I sometimes do when there's a lot going on etc. At the end of making the video, I ended up having to replace one of the the Darlington Packs (STK0050), it was producing some very intermittent noise. That of course didn't make it to the video either. As far as going any further with replacing the regulator, or anything else, I just wanted to get this thing cleaned up and resolve the "channel issue" so I could get it back to the customer. Thank you for bringing up the info concerning the voltage regulator, that's good advice / good info. Again, I appreciate you chiming in.

I practically had to hose it down, it sure was dirty enough. I got in there with some small brushes and a "micro" vacuum tip to get all the looser stuff sucked out, then I followed up with 99.9% anhydrous alcohol "misted" onto the boards and then brushed off. Otherwise, thanks for chiming in have a great day !

Perhaps in the not so distant future I'll do the tour, thanks for chiming in with that suggestion, have a nice day 🙂

Hello there, Hopefully I can explain it in a manner that describes the process clearly. Reach your index or middle fingers (whatever feels right to you) under the rim of the holes off to the sides (lateral) of the center spindle, and place your thumbs over the top of the center spindle. With your thumbs, you're going to push down slightly while you pull up the platter with your other fingers at the same time in one motion. That should "pop" the platter off. Just don't push down on the spindle with brute force, the thumbs are positioned as such just to steady the process and give you leverage. Hope that helps 🙂

My pleasure, thanks for the comment.

My pleasure, I'm glad you enjoyed some of the info. The 771 you just finished up is another fine receiver. Sansui is right up there with my favorites. Thanks for chiming in, I'll check out your channel and see what you got going on. Till next time, take care Trevor.

Hello there, I'm currently working on sourcing some quality cartridges / parts etc., after which I'll be resuming re-assembly, testing, adjustments and so forth. Thanks for chiming in and enjoy your upcoming restoration as well, have a fine day 🙂

Sí, normalmente funcionará bien ya que no hay una gran diferencia entre 8 y 6 ohmios. Sin embargo, tenga en cuenta que con altavoces de ohmios más bajos (6 ohmios), la sección de salida/los transistores de salida consumirán más energía. Por lo tanto, existe una mayor posibilidad de que los transistores de salida/sección del amplificador se calienten y tengan que disipar más calor. Si no lo usas continuamente a un volumen muy alto, no debería haber ningún problema. Incluso cuando se usan parlantes de 8 ohmios a volúmenes altos durante largos períodos de tiempo, el amplificador se calentará más que si se usa a niveles de volumen más reducidos. Además, mantenga los valores de potencia coincidentes (dentro de lo razonable) entre la potencia de salida del amplificador y los altavoces. No querrás dañar los parlantes que no tienen suficiente capacidad de manejo de energía, especialmente cuando escuchas música a niveles de volumen "altos". En otras palabras, algunas de estas cosas son de sentido común, espero que esto ayude, que tengas un buen día.

Tengo esos archivos guardados en formato PDF en mi computadora, deberás enviarme un correo electrónico y te responderé con los archivos adjuntos. Mi dirección de correo electrónico es ernest@retroelectrotech.com Intentaré entregártelos lo antes posible, pero puede que tarde unos días porque estoy muy ocupado en la tienda en este momento. De lo contrario, que tengas un buen día.

Hope you're able to track down the problem, so, many things that can produce static.

Glad to hear you got it resolved with some clean up. Thanks for chiming in, have a nice day 🙂

Hello there, yes, I would imagine you're running hard and heavy with service calls, installs and everything in-between. by all means, live vicariously rather than trying to prop yourself up at your own bench and fight to stay awake. When things lighten up a bit you'll have a few nice units to work on, so, till next time, my best to you 🙂

Yes it is 1/4 inch, have a nice day 🙂

Glad you enjoyed it, take care 🙂

Glad the video is helpful, and good to hear you're working on your 771, it's a nice receiver / amp. In regard to board cleaning, when I'm removing flux, or some other miscellaneous crapola from a board surface (in most cases, and I've cleaned tons of boards), I've had no issues with 99% anhydrous alcohol and a brush. I do it all the time in this vintage gear (etc.) and haven't had any coatings breakdown and turn to mush etc. There's always the exception to the rule, so as you know / mentioned, it's a good idea to test your solvent on a small area. Again, you should be fine with this equipment. Thanks for chiming in, and my best to you and your re-cap project, enjoy the tunes 🙂

@@retroelectrotech Once I get going on my project, I plan re-flowing all solder joints on each board to compensate for thermal expansion and shock stress from years of use. I'm confident my soldering skills will not introduce unforeseen problems. I wonder if this step alone might even negate the need for a recap job - altho I still will. Do you have a favorite reasonably priced solder station? I always had great success with Weller stations 20 years ago, but reviews show their quality has suffered greatly since they began building them in China. I also love Metcals, but unless I can find a used one, they're out of my price range. Tried Hakko and a few Chinese models over the last 5 years on a company autonomous vehicle project, but they seem to lack acceptable tip heat control. No matter how I try, I can't flow a good joint. Would never attempt them with to trust on my Sansui boards without pad damage. Any thoughts? Thanks again!

@@andthepoetliftshispen5752 That's definitely a good course of action going through and reflowing solder joints. I find a very high percentage of connection issues present in one form or another. I to appreciate the quality of the old soldering stations that held up to the demands of day in and day out heavy use, I've owned several. As you mentioned, if you want to stick with an old battle proven station, I'm sure you can find one on "the auction site" that is still in decent shape. At present, I use the Hakko FX-888D. I haven't had any issue with unacceptable performance maintaining tip temp, it's been a solid, stable unit with a nice smaller footprint. I can't speak for all Hakko stations, because I haven't owned anything other than the station mentioned and a Hakko de-soldering gun, the FR-301, which does a good job if properly maintained. Actually, if I'm not doing a ton of back to back de-soldering, I actually prefer to use a manual vacuum pump or wick, but I digress. Again, the Hakko soldering station mentioned has done well subjected to the volume of work I throw at it. There are situations when I need to tackle some large areas of circuit board and chassis soldering etc., that call on me to break out my old Weller 8200-N (Gun). Otherwise, I get by just fine with what I mentioned 🙂

​@@retroelectrotechThanks again, bud. I'll look into the Hakko, and if I can still find one, I'll buy my old reliable pre-China Weller CPT! Happy trails!

Glad you've had success with the rubber rejuvenator that you use.

Earl Grey and Steel ;-)

A shriek of pleasure or one of pain? 😀

@@retroelectrotech pain! 😂 the lavendar caps are the worst but i do not trust any of them in vintage gear. oddly, i still use modern panasonic caps.

@@josephlalock8378 I haven't had too many issues with the Panasonics, at least no more so than the numerous / random bad caps I find throughout a lot of this old gear. But then again, I realize mileage will vary for different people servicing different "specimens" of equipment. I've heard some talk about their leakage and so forth, but again, I run across my fair share of both physically and electrically leaky caps from numerous mfg's. Different makes, series and batches appear to hold up better than some, but ultimately, it's best to go with cap choices you feel comfortable using. I also still use Panasonics in some applications, and so far so good, time will tell the tale. That said, the fact that a good majority of electrolytics in vintage gear have held up all these decades is pretty darn good. In the next 40 or 50+ years, I wonder if this "new age" of caps will prove to hold up better? They say the quality has improved, so again, time will tell. Anyway, have a good one Joseph 🙂

@@retroelectrotech the lavendar caps are notorious for their legs corroding(turning green) surprisingly, there was a thread on AK a while back where several members had brand new panasonic caps and their legs were turning green. google "lavender capacitor legs" and the first image will show you what i am talking about. take care brother!

I'm glad you enjoyed the video, we shall see if the customer changes his mind down the road, it does happen from time to time. Have a nice day and thanks for chiming in 🙂

glad the video was useful to you, have a nice weekend 🙂

@@retroelectrotech Hi Mr. Retro Tech :) Although this video provides a hell of a lot more infos than the usual "deoxit and done" kind of servicing advise it didn't show what I was hoping for. My Problem is/was as follows: I am servicing a Marantz 4400 and when I got to those 4 way PITA type of pots I had a huge problem with reassembly. There is some sort of copper clamp in the second "chamber" which is held in place by the outer part of the shaft which is bent outwards to hold the plastic part where the wiper is mounted and at the same time this clamp. I wasnt able to the the inner shaft past this copper part and its kinda impossible to get to it in order to open it while pushing the shaft through...Just too many parts to keep in place and no room for any tools to insert. did you take one of those apart and back together when you did the 4300? In general there is so many different pots out there and just as many ways to take each and every one apart. I know its a lot to ask for but could you maybe make a video someday showing how to take the tricky ones apart and how to reassemble? If you like I could help with that and provide detailed pictures of disassembly and assembly of quite few of those bastards... I have several hundred vintage pots and took many of em apart and back together but there is some of em which are super super difficult to work on.

@@arnejensen9216 Hello again, yes I agree, some potentiometers are very difficult / almost impossible to disassemble and reassemble, especially without causing damage. On the Marantz 4300 I recently worked on, I didn't completely disassemble all the potentiometers on that unit, however, I have had my share of very difficult disassembly situations involving potentiometers and switches. Some potentiometers weren't really designed to be completely disassembled and serviced, but regardless, sometimes it can be done very carefully with some potentiometers that are very difficult to source / substitute. In other words, the only time I attempt to service (disassemble, repair and or deep clean) such potentiometers is when there really isn't any other options, and of course when the customer is willing to pay for that level of service, as well as with the understanding that there is no guarantee the procedure will be successful. On the other hand, when it comes to other potentiometers that are more serviceable and can be disassembled a lot easier, I have no problem doing so if the pots need that level of service and the customer will pay for that, because it is more time consuming of course. As far as the problem you're experiencing, I think I know what you are trying to describe based on your "word descriptions", however, I would probably need to see a photograph to be certain. It appears you are referring to the section of the shaft that is "flared" a bit to form a tight pressed fit to the phenolic disk that the carbon / resistive track is applied to. If so, yes, there are some differences in the way those sections are held together, and as you know, they can be very difficult to separate without damage. It takes quite a bit of improvising to separate those sections carefully and to reassemble. Again, without seeing exactly what you're encountering (even though I have an idea), it's difficult for me to give any suggestions regarding how I would handle the problem, or if I would just back off and try to source a replacement etc. If you want to send a few photos of the issue you're describing I'll take a look at it when I have a moment, my email address is ernest@retroelectrotech.com

Hello there Joseph, hope all is well, been extremely busy as usual as I work "hard and heavy" to thin the herd in here as well. Yes, nothing wrong with a little "switch cleaning enhancer" / herbal remedy if it gets you through those long sessions, and yes, gotta have the tunes to complete the experience. Sounds like you're getting through your restorations at a relaxed and steady pace and that's a good thing. As far as the acquiring of too much gear, it happens, just kinda comes with the territory / nature of the biz. With time you'll tame the herd, sell some off, trade some, acquire other pieces of interest, hence, the cycle will continue, but in a more "selective" manner. I have my fair share of gear I've acquired over time, most of it due to be restored for sale and a few pieces near and dear to me that I'll keep. Otherwise, I mostly turn away equipment, unless it's something really worthwhile. Otherwise, I hope you get around to building speakers again soon when it cools a bit, my best to you as always, talk soon 🙂

Indeed, I still entertain myself with toys, next time I'll set the speed to 78 rpm and see if they can stay on the platter ;-) Have a nice weekend!

The fuse you're referring to is a 250v 8 amp fast blow type. Since you have the "blown specimen" I assume you know what size replacement you need, but if not it's 1/4" by 1-1/4". Yes, hopefully the fuse blowing / opening is an isolated incident, i.e., sometimes fuses will open when there is not a problem with the equipment / circuits they are protecting (for different reasons). However, in most cases, there is a "fault" situation causing the fuse to do its job and open. Otherwise, be very careful troubleshooting the problem if you're not properly set up to perform "safe power ups". My best to you, hope you get it worked out.