Discussion in 'Yamaha' started by LFazio51, Nov 25, 2017.
Beware, sometimes the Mtester fails in measurement .Maybe for some contact problem.
Finally we're now on a new page, have a nice lunch
We need to start calling you Professor!
You should have gonne into teaching because this is a gift that not many people have.
Thank you for the comprehensive lesson!
First, I can't thank everyone enough for helping with the thread/project, and specifically Oilmaster for sharing such comprehensive information. Before I get into some technical details I would like to pose a quick question to those experienced and watching this thread - please give me some feedback on "thread etiquette." I see many have eluded to "getting to the next page" and I'm well aware that I'm "long-winded" so, any advice on posting topics and the manner for which I am posting may make this more enjoyable. The problem is my limited knowledge. It causes me to get very detailed in hopes that I ensure the correct approach. Coupled with this is the degree of difficulty this project presents and trying to get everything tested and upgraded in a way that helps eliminate future entry.
Yes, given the variety of test results with three different devices, I can see that accuracy will only be acquired by removal. The problem is, I'm trying to "slip down the funnel" and only remove those that appear suspect. I really don't want to have to remove each and every small transistor. As a result, I was hoping to get some feedback on the test results in order to accomplish this.
So at this point, some directional advice would be well appreciated as I think most are aware of my limited knowledge. Should I just recap the main amp boards and replace the TR611/12 transistors or start to remove and test the suspect trannies?
I've learned that the ECB indicators on the board (black square specifically), is the emitter. I'm also aware that just because its represented on the board or schematic doesn't necessarily mean that they are installed that way. I've also learned that newer transistors cannot be installed until you are certain of the orientation of those removed. And while this bothers me more than the typical errors found with capacitor reference and board markings, the information Oilmaster shared should help tremendously. I'll have to spend some time "digesting" the data shared as I know its going to help eliminate mistakes.
SO, MY CURRENT STATUS IS...
I started "testing" all transistors on the main amp board last night and was going to document and upload. Again, any advice is well appreciated as there may be some on this thread, that when taking into account my knowledge.skills, feel I should just move forward with the recap and replacement of 611/612. I would really like to get everyone's opinion so I can either validate the process moving forward or, alter directions.
none of it was aimed at you.
I think Avionic ruined everyone's lunch with page 8. Hint: what do you see at the top of page 8?
You might have posted that earlier..I am assuming.
LOL Mmmm Mmmm good.
hèhè, that's what I meant with humour
That fungus nursing room.....urrghhh
Which was another topic that you asked for: how to clean the PCBs.
Well, I usually do it before and after the rebuild, needing four ingredients:
1) PCB flux remover, like this one (big version here), with integral brush tip on top of the spray can
2) Old-school liquid dish wash soap (or spray bottle kitchen detergent for stove grease removal)
3) 1/2" soft paint brush
3) Tepid water tap
Doing the cleaning in a sink that can handle the flux liquid (stainless steel or true ceramic sink)
The hand holding the PCB may appreciate a latex glove.
Before first cleaning, I firstly remove all parts that will be replaced and clean up any remaining solder left at open solder pads (as I like defluxed soldering areas for soldering in new parts).
Big items that can trap water inside like relays should be removed as well.
Then make sure all items are readily at hand, in the sink:
1) Release flux removal liquid on the solder side, while keeping the PCB nicely level (or else the liquid falls off too soon), and thoroughly rub with the brush on the spray can, making little circles, ect. Release little extra amounts of liquid on the PCB while rubbing it, better a bit too much then too little. Around a few minutes of soaking and rubbing is usually enough (always keep it level, only tilt/turn at the end of the drill). Your are done when all brown/black residue is dissolved. Also all possible transparent lacquer-like coating (a tropicalisation treatment) should be dissolved and gone. Keep adding flux liquid and brush until the entire board seems really flush.
2) Turn around to the component side and do a general flux release and gently brush around (PCB + parts)
3) Now, rinsing it with tepid water at this moment would leave a lot of white stains and shaded areas, and there is a trick to avoid that. Prior to rinsing it with water, apply a good dose of pure liquid dish washing soap (or kitchen detergent spray bottle) on both sides of the PCB and start soaping both sides thoroughly with the paint brush. At the same time, get the tap running to get the tepid water ready (don't rinse yet). When soaping around, brushing all surfaces and parts in detail, you probably end up with a good layer of foam after a minute or so; make sure no areas or parts have unsoaped places left; free reflux liquid will give stains afterwards when directly in contact with water. When you are sure, thoroughly flush the PCB on both sides under the tap with running tepid water until all traces of soap are gone.
EDIT: the liquid dish washing soap does do its job better when slightly pre-mixed with water, so often I premix it in a soup bowl (say 3 parts of soap to 1 part of water).
4) Dry off any free water (towel or something like that for the solder side, and all PCB edges), and some compressed air (spray bottle) to drive out water under/around components.
5) Let it dry overnight above a mildly warm room heater (no hot environment !!) Some folks put the PCBs in the oven at low temperature for an hour or so.... I don't like that due to the risk of bulging the PCBs.
Now, it might be better to wait 2 to 3 days prior to any soldering, as remaining water vapour inside the PCB's fibre structure may cause steam which detaches the solder pad from the board.
After rebuild: the same deflux-soap-rinse operation basically, and no power-up for at least 3 days.
Items which can trap water (like relays) or that can oxidize again (like switch/selector contacts) should only be soldered in after the final deflux/wash.
Be aware of possible trapped water under large capacitors; do make sure all is well dry !
You'll be surprised how shiny your stuff will be
Give us some before-after photos
Re transistors testing; it's understandable that you wouldn't like to pull all of them, but it is the only option if you want to be 100% sure.
I might add a warning here:
Really know your detergent before working the component side!!!
I had instances where the detergent actually celeaned out the componente so good that there were no markings left on them
on the other hand, for the solder side the same detergent worked wonders with the old flux. ......it turned out it was an industrial degresear I bought many moons ago to clean my BBQ Grill.
you mean something like this???
this should open your apetite
here still going through the soldering process of the replacement components
after last cleanup, before puting it back in the cage
I know, I need to get a better camera, but you could even see a fingerprint on it from a mile away
Also I might add that the fiberglass boards of the B-1 are not inherently as shiny as other PCB types, yet shiny enough
Seen that before..
Thanks Pete, that's an excellent example !
You left a fingerprint ?!?!?
this is one of the better boards I have
learned from the best
CAUTION - PHOTOS AND PICS IN THIS THREAD MAY CAUSE LOSS OF APPETITE, NAUSEA, FRUSTRATION, ANXIETY, BOREDOM, AND MOMENTARY FEELINGS OF EXCITEMENT. IF YOU EXPERIENCE ANY OF THESE SYMPTOMS, PLEASE CONSULT YOUR PHYSICIAN IMMEDIATELY!
Digestive adjustment photo below...
I've also located the necessary PPE for @Oilmaster cleaning process
TR712/715 - I realize this is not necessary on the CR1020 as many have indicated, however, what the hell! Nothing like a little custom engineering to make one feel good about their efforts! Lots of opportunity to improve the precision of fabrication but I think it will do the job.
Good job going there
Your custom heatsink is nice; but don't forget to have electrical isolation between the TO-220 transistors and the heatsink.
One more thing now that we see the chassis bottom in that last photo. I have kitchen detergent (MrProper for stove cleaning) which also makes galvanised surfaces look like brand new.
Now that the transformer is out anyway, don't be shy to put the entire remaining chassis in the shower and give it a good soap and rinse.
Alright people - FULL DISCLOSURE - I FEEL LIKE AN IDIOT! I saw Oilmaster's Post (#157) late Friday evening after imbibing my fair share of adult beverage, and I think it goes without saying, was unable to "grasp" the humor at the moment. My response the next morning was obviously driven by my thoughts from the night before, which resulted in that ridiculous lengthy response! LMAO! I'd like to consider myself a tad "sharper" than that but maybe not! I'm sure Mr. Yamaholic was thinking If I have to explain this, maybe this guy should just step away from the bench and send the project to someone a bit more capable!! I know that's what I would have been thinking! As one of my all time favorite bands would say, thanks for indulging my Momentary Lapse of Reason! At least it added some "levity!"
Will be purchasing the insulators when ordering the transistors
I'm having some difficulty "wrapping my head" around this concept but I'll go with it. No Mr. Proper available here but I'm sure another oven cleaner will perform similarly. My larger concern involves determining what I would need to isolate from the water. I'll remove the faceplate and knobs, but take a look at the photo below and let me know if there is anything more I need to know before putting the dam thing in the shower!
Can't tell you to do it (i.e. do it at your own risk), but if I were in your situation (and I am in your situatio alot), I would consider doing the following:
1.Pull out your camera
2.Take a buch of photos, multiple photos from each angle
3.Take a screw driver and separate everything form the chassis
4.grab some heavy duty industrial degreaser or BBQ grill cleaner
5. Take the chasis to the tub, spray it and let it sit covered with the heavy duty cleaner for an extended period of time, then scrub and wash-off
if you decide to go through the trouble, Iet us know how you did.
I bet you see that alot. You got a dirty job my friend
Separate names with a comma.