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@ctt956- Thank you. Unfortunately, the electronics repair guy said he couldn't fix it. He said it was beyond his ability. So... I may not have any choice but to give up on it for now. If it's beyond his ability, it's unquestionably beyond my ability as well. Bummer.. Hopefully I will get lucky and come across a PT-30 or another PT-31 eventually. They don't seem to show up very often and I think buying it off eBay is way too expensive these days (especially after shipping and import taxes) Anyway, thank you all for the responses. I'll keep this thing around and hopefully figure out the problem someday.

Side note: Does anyone know how the hip hop sounding beat that starts at 3:37 in the video above is achieved?

@Chas - Thank you for sharing this. I have seen it before actually and it was one of the things that set this journey in motion. I have some soldering skills from working in a factory for about a year making some complex wiring harnesses for a thingamajig that is not worth explaining here. I have to admit, however, that I did this job without having much understanding of how everything actually worked. I see now that tracing things in reverse and fault-finding are completely different skills. I have almost zero experience with that and I know it will take a lot of focused effort with finding and watching the right videos to grasp some useful concepts and methods. Now that I'm off work for awhile, I can spend more time on this and I can utilize ChatGPT (AI learning tool) in combination to give me a crash course on basic electronics concepts and problem-solving. I will open up my MT-68 in the coming days to get my first visuals, then I will start trying to link together all the information that has been provided so far. Just to be clear, the MT-65/68 is the best possible model for unlocking all the extra features? The MT-400v has some disadvantages, right? Does it lose some functionality from this model replacing some of the chips abilities in the MT-65/68 or are those added functions separated? For anyone following my PT-31 thread: I found a local guy that my musician friends go to for electronics repairs. He has been very good with everything they've needed so far. I'm not sure what the outcome will be with my PT-31, but if he is successful, I will bring in my MT-400v and that model could become an alternative modification project. I'm noticing now that my MT-68's slider caps seem to have been glued on. The past owner(s) may have gotten tired of losing the damned things (it's obvious that there are scavenged replacements from a more or less UV light-affected MT-68/400v donors and an MT-65) ... So.... getting to the last circuit board layer could be difficult unless I'm going to make some sacrifices. I haven't opened this up to see if that will affect anything though.. so we will see. Hopefully I won't need to pull out the slider pots. Any thoughts on this, anyone?

An update for anyone who is interested: Some of my bandmates recommended a Thai guy who fixes electronics locally and they had some good results. I messaged him and dropped off the keyboard. I get the idea that he doesn't specialize in more complicated electronics, but I have no idea. He has repaired all kinds of appliances and guitar amp stuff. Now I'm just waiting for an update. Let's see if I get lucky.. Maybe it will be a cheap, quick fix that I couldn't identify myself. Or maybe he will tell me that this thing is hopeless and he can't help me. I gave him the little 2k trim pots I bought and I mentioned that I'm not sure if it's the correct part. I'm not sure he knows either. Pray for my poor little junker Casio. I really like this thing for some reason, so I'm hoping it can be brought back to life haha..

@CYBERYOGI =CO=Windler - Thank you so much for clarifying the meaning of the "B" that is printed on the board! That makes a lot of sense to me now. Ok, so we know for sure that it's 4.7k for the PT-30/31 models? It's definitely the same as the PT-80, which is what we got pictures of? That's where we got the whole 4.7k idea from originally. I assume a lot of the parts are the same. I just want to be 100% certain before I put the time in to installing either of the parts and find out it's wrong. I saw a PT-30 for sale today on FB Marketplace but it had a broken screen. It sold shortly after I looked at it. I'm not sure if I should be kicking myself for not buying it.. but it was a little beat up, and the seller wanted $20 for it. I already sunk $9 into my broken PT-31 (which I had falsely been told had a working screen and powered on) so if I sink another $20, I'm basically at $30 for no guarantee. It's not a lot of money really.. but I don't know if I would be capable of transplanting the screen from the PT-31 with that delicately thin ribbon cable, or if the PT-31's screen is even still functional as a separate part. Argh.. I guess the waiting game continues. Honestly, if I find a working PT-30 and the case is not perfect, I will consider transplanting everything into the PT-31 case because I really love the way it looks. Is that a really absurd idea? Haha. What am I doing with my life.. T_T

I would like to turn my nicely worn, and dearly beloved, MT-68 into an experiment and a test of my soldering skills. I want to isolate each instrument (main voice, accompaniment chords, bass, arpeggiator, kick drum, high hat, snare, etc) and send each of them to separate outputs. I would like to figure out the best way to do this. As I understand now, thanks to responses from this forum, the basic idea is that each instrument gets sent to a kind of "mixer" in the circuit, which outputs everything as a blended mix from the single output jack.. So I need to trace the path for each of the separate instrument and interrupt them before they reach the mixer so I can add switches that cut off the circuit path or send the signal to my isolated path. For the drums, specifically, I think I would like to set mute switches for each of the instruments, but I probably want to have them all on the same output.. but I think having the bass drum isolated would be an advantage for EQ and effect purposes. That way, I could set some side chain compression processing to pump the bass more in my DAW (Logic Pro) if I keep it specifically isolated. My goal for isolated outputs is to modify the EQ and add effects to different parts. Maybe that's obvious, but I thought I should mention it now. Having everything blended together is not ideal for recording purposes because it limits the creative control with adjusting the EQ and adding things like chorus, tremolo, distortion, delay, etc. I would like to have a row of tiny switches that I can affix to a little wired bar of some kind that I can store in the battery compartment, which I have no plans to use (this was not my original idea.. @Chas mentioned it first in an earlier conversation) .. so I think my first step is to measure that carefully, and then, I need to draw a precisely measured concept on graph paper maybe. Next, I imagine, I need to decide how many switches I need and figure out which types of switches are possible to add on a little control interface within that limited space. I have an idea of the switches I want, but I don't know if they are ideal. I need something that is easy to switch on and off without much room for error. As the moment, I imagine I need an output/mute switch for each of the following: 1. the main voice 2. the drums (excluding kick drum) 3. the kick drum 4. the bass 5. the arpeggiator 6. the accomp. chords I don't doubt at all that I am forgetting something or saying something dumb or shortsighted. Does anyone want to dream along with me? I plan to document this along the way. It may be a slow process though. I will do it as I have time. Thank you in advance if you are interested in this. For me, this is a learning journey in electronics and also the first step on the path of (hopefully) creating one of my ultimate dream instruments.

I should have the little trim pot piece in a couple days or so and I'm about to start my vacation time finally. But.. I'm not sure if I got the wrong value potentiometer. I ordered 2k because I saw "2.2KB" printed on the board in that part's place, but I never learned what the "B" in "KB" is for.. I can't find an answer on the internet. Does anyone know? Is it possible the PT80 uses a different value for the resistance of its tuning trim pot or do I need to order and wait again? I don't want to go through the trouble of soldering this thing in to find out it's the wrong part and it won't function correctly but I don't know where to get a solid answer on this since no one seems to have clear pictures of the inside of a PT-30 or 31 or the service manual. I get the idea that it's better to have a pot with higher resistance than one with lower resistance if the exact measurement can't be found. I don't see anywhere to get the 2.2k rated pot, but I did find a 4.7k, which is strange because all the other options are rounded to the nearest hundredth or thousandth place (ex: 1k, 5k, 10k, 100k, etc.) Thanks in advance if anyone has an answer for this. It would save me some time. I'm not sure if this is a lost cause. Originally, I wanted to earn the pride of fixing it myself, but lately, I just want to hand it over to someone else and pay a bit of money to fix it or find out if it's even possible to fix it, because I have no idea what's wrong with it.. but I have no idea who to take it to. I imagine vintage toy keyboard repair people are pretty rare, and in Thailand no less, it's even more of a challenge with the language. I know electronics are quite similar across many different types of devices so maybe it's possible to find someone.. but I feel like I'm going to get weird looks taking a dinky little toy thing into a computer repair specialist. What do you guys think? For now, I am going to wait for a confident answer on the potentiometer (even though that probably won't fix the fact that it doesn't power on at all) and work on a side project. I'm going to add an output jack to another keyboard (my Yamaha PSS-100) and start planning out the isolated output mods on my MT-68. I have already fallen in love with my new MT-65, so the 68 is definitely becoming the lab rat. I'll make a separate post about that soon if anyone wants to follow along and help with my newbie questions.

@CYBERYOGI =CO=Windler - I will probably have to stay away from that mod because I don't understand what kind of switch can do that or where to connect it. That's ok. Maybe it's not my place to dig into that level of electronics. I want to someday, but I feel like I would likely get in over my head very quickly if I were to even attempt the first steps. I will remember you for future modification explorations. For now, I think I will stick to the easier modifications. @Chas- Ah.. it's too bad I already ordered a different part. I don't know if the part is the same between the 2 models anyway.. I wasn't sure when I would get a response so I ordered a 2k pot to expedite the shipping process. I saw 2.2kb printed on the board in that spot so I went with the best guess I could figure. It's odd that it says "kb" though.. Why doesn't it just say 2k? I feel like I'm missing something. What does the B stand for in 2.2kB? I'm clueless. At least it was only a dollar or so.. if it's not right, I just have a bag of useless doodads in a drawer I guess. Can anyone clarify the "kb" thing? @CYBERYOGI =CO=Windler - I don't doubt your expertise at all. But I do find it odd that the only destroyed parts I can find on this whole keyboard are exactly where someone would stick a screwdriver in. Why wouldn't any other parts have damage? I understand there is possibly damage I can't see.. but really.. Everything looks very clean and tidy except for those 2 exact spots. They are physically broken unlike anything else. There is no other physical damage at all. But I still don't doubt that it could be a combination of issues though.. Has anyone lost any hair from this stuff? Haha

@pianokeyjoe- Ahh.. I made a huge mistake! I was not looking at my keyboard when I posted my response. There's an arpeggiator on/off switch, but there is also a 4-way selector switch for different patterns when that switch is ON. I tend to respond to this thread in the late evening when I've already been exhausted by my daily work. That's my excuse for the moment.. but I feel a bit foolish too. Well.. I guess I have to brush that off and move forward with more focus. I appreciate your efforts to pull me back towards a basic understanding without shaming me, and I'm glad we have similar visions of what the ultimate "toy" keyboard should be. I think we both appreciate the auto-accompaniment options and the unique tones of these models. There's a special quality that nothing else seems able to create authentically. I look forward to the direction of this discussion as my time gets freed up over the coming month. For me, it's a slow process of trying to figure out the right questions to ask (when I have the time) and then trying to understand the answers, and then correctly executing the actions that achieve the goal. I don't have any updates for anything at the moment because it's a busy week. But I'm curious to hear about anyone's current project with modification, repair or dreaming up new things.

@pianokeyjoe- The extra arpeggio patterns are already active? I thought it was just an on/off switch with one standardized arpeggio pattern for each rhythm. It’s possible I’m misunderstanding the meaning of arpeggio 2 and 3 though. The more I think about it, the more I feel like the transpose option isn’t really important. It would be nice for “cheating” and staying on the white keys though. Admittedly, I’m not so great at playing keys. I mostly just use them to record one part at a time. Anyway, I am definitely not ready to go into more serious modding yet, but it’s interesting to start thinking about it. If it involves any soldering on the processor component, I will probably be too afraid to make a mistake. Those little leads coming off are too close together for me to feel any level of confidence on an irreplaceable part like that. The isolated multi-output mod will probably satisfy me. But I want to understand the arpeggio possibilities too.. Could there be more?

@CYBERYOGI =CO=Windler - I see there is also arpeggio 1 and 2 unlockable features. Would you just set a button for these also? If you don’t mind me asking, what would be the most ideal way to activate these features as a physical mechanism on the outside? I imagine individual slide switches.. but maybe that would interfere with the already-existing slide switch for (what I assume is) arpeggiator pattern 1.

@CYBERYOGI =CO=Windler - You make it sound like it's possibly a lot easier than I was expecting. I need to put a button somewhere that interacts with the chip to say the transpose function is temporarily "ON" while I press any key other than C and it will move everything relative to that? I wonder how you would activate transpose up vs transpose down though. Hmm.. (I am editing this afterward because I thought about it a bit more) I understand the concept, but actually physically executing this will take some time to understand I'm sure. I see this as a long term goal but it's nice to know that there's a path to it that doesn't sound too wild or dangerous. I appreciate the info

@CYBERYOGI =CO=Windler - Wow, that is super thorough info. Thank you. This will come in handy when I start to look into the possibilities of modding my MT-68 or 65. The 65 just came in today and it looks very good after I cleaned it up a bit. I guess that means the 68 will become a future mod project. That seems to make more sense. I think I only want to add isolated output jacks on the MT models since I imagine that would be a more simple mod. Having a transpose option would be really great though too, if it's not too complicated. I will have to research that for awhile. I wonder what the best type of part would be for rotating through the levels of transposition so the processor understands clearly. That's a question for later.. I better focus on what I can do for now. I think my first projects will just be to fix the PT-31 and the MT-400v. I'm just waiting for the 2k trim pot to come in for the PT-31 and I think I will open up the 400v further during my December vacation and continue on that thread again with my findings. Thank you so much for the continued interest. Your responses make this journey a lot more exciting.

@pianokeyjoe- I’ve had dreams about finding musical treasure like that. I wonder if this keyboard idea will come up in my dreams also. I’m a bass and guitar player mainly but I’ve recently gotten hooked on these little toy-like keyboards and I can’t stop thinking about them. It seems the general rule for these things for me to like them is that they have to be from the early 80s or they don’t seem very cool. I can’t understand why on earth Casio stopped continuing the evolution with their early vision. The auto-accompaniment, arpeggiator, analog drums, etc.. They had an amazing thing started. Anyway, my white MT-65 should arrive today. I hope when I open the case, I will suddenly become obsessed with the white models. The white PT-30 is a lot easier to find and I can keep my grey models for modification projects. Can’t wait! Has anyone done an isolated output for each instrument kind of mod yet? Curious to hear how that turned out if anyone has done it. For me, this would be the best thing to do. That arpeggiator would be killer if it could be separated and run through effects like tremolo, delay, long reverb, chorus, etc. The isolated bass would be amazing isolated through a synth bass octave pedal to get a fatter dub sound. Drool.. I don’t want to get too off topic here, but has anyone tried the Yamaha MK-100? That’s the model that got me started. I bought it on a whim and research of similar keyboards has led me to all these great Casio models. Could be a fun one if anyone wants to explore a different brand. The drums and accompaniment styles are not as good, in my opinion, but it adds some very unique features that I haven’t seen anywhere else.

@CYBERYOGI =CO=Windler - Nice detailed info. I really appreciate that. So there’s no cross-over between the MT-65 capabilities and the Super Drums variable patterns? Bummer.. Too bad the MT-65 stuff didn’t get developed further and physically downsized. It would be the ultimate casual home keyboard to this day. I think a lot of modern stuff adds too many bells and whistles. I want a PT-30 + MT-65 + added 400v functions in a tiny package. Oh well.. guess I just have to appreciate what’s already there.

@pianokeyjoe - ah, I agree that it’s a good idea to play around with models that are less desirable but my girlfriend is becoming more critical of my keyboard collection lately and I don’t think the big ones will fly under the radar at all. Maybe that’s another reason I’m starting to love the PT-sized stuff. They are easier to hide away and they take up less space so they are a little bit more justifiable, for me anyway. The MT-68 is more special for me than the 65 for the moment, but I haven’t received the 65 yet so it may change my mind. My 68 has slider pieces and a volume knob salvaged from other MT-68/65s. I kind of like it for the idea that it’s kind of a makeshift space junker like a Star Wars ship and it was really cared for throughout its lifetime, despite the scratches. I can’t wait to compare it to the 65. Hopefully there are no hidden surprises for me to find when I get it. The guy showed it to me in a video but the language barrier prevented me from checking every function. Anyway, thanks for the info on the similar models. The boombox looks interesting, but I imagine it’s really hard to find. Maybe it’s bigger than I want also. Hmm.. I’ll keep an eye out for it. Looks like it would make an awesome show piece if nothing else. I just ordered the 2k variable resister pot and I should get it in 2 weeks. By that time, I will be on an extended vacation time so hopefully I will have enough extra time to get to the bottom of this PT-31 mystery. I will look for a suitable switch for the reset function also. Would you happen to have a recommendation for that? I’m not sure I can imagine it yet.

@CYBERYOGI =CO=Windler - Oh, side note: I know the PT-30/31 aren't related at all to the MT-65 .. I was hoping the chipset from the latter type of model might be available in a PT-sized model, but from a little bit of research, it looks like the answer is No, it's not. There isn't a smaller keyboard that uses that chipset. Too bad.. I think the drums and all the possible unlocked features from the MT-65 would be amazing in a smaller form. I love the feel of the tiny keys and the portability, as I mentioned before. Oh well.. The MT-52 looks especially interesting with the Super Drums feature. I would love to have that functionality on top of the MT-65 stuff. I'm wondering if those MT-52 features can be unlocked on the MT-65/68. That could be really interesting. The thing that attracts me the most to the PT-30/31 is having all the little chord options on the side with tiny buttons and the sequencer. The transpose option is a great addition too. I want to add that functionality and form factor to the sound quality of the drums and voices of the MT-65. I don't think my dream keyboard exists so I will have to accept the limitations of each model and appreciate them for what they are. Limitations are actually great for creativity in my opinion.

@CYBERYOGI =CO=Windler- I haven’t seen any other parts that look corroded or anything. Since the broken parts are both in places where someone could stick something inside and stab around blindly, I want to say they probably got damaged from negligent abuse. The rest of the insides look nice (as far as I can tell) and there’s only a little bit of dust here and there.. mostly just from the disintegrated foam. Do you have any recommendation for dealing with the missing reset button? It’s just a piece of metal on a spring that bridges 2 contact points, right? So.. that function could be achieved by just using a flathead screwdriver tip, right? I think I may just bring this thing to an electronics repair guy locally and see if a more experienced person can get to the bottom of it. The LCD screen and it’s cable seemed to be in pretty good shape as far as I can tell. Nothing seems to be falling apart and I haven’t found any obvious corrosion outside of the battery compartment. Hmm..

@pianokeyjoe- I REALLY hope it's not the CPU. I know that would ruin all hope of bringing this thing back to life because there's no way I'm going to try to replace it or troubleshoot it by making a complex diagram like the guy in the video. That stuff is WAY out of my league right now and I doubt I will ever want to go that deep unless it's something super rare and valuable. It's a hell of a lot easier to just buy a new keyboard. I'm really attached to the PT-31 specifically though. I like that aged grey tone with the pink accents but this model is a lot more rare than the white PT-30 version. T_T Anyway, about the reset button. There isn't even a little piece there. Something has been broken off, I'm quite sure. There should be a little moveable piece of some kind, right? That may not have any effect anyway, but it's all I can find so far. I'm thinking MAYBE the power button graphite is too worn out to get good electrical contact.. I know there was a suggestion to modify the circuit to bypass that and keep it "always on" but I don't know how to do that quite yet and I'm afraid to ruin things more by making a mistake. It shouldn't hurt anything if I use a standard pencil to draw on some extra graphite, right? I bought the MT-65 by the way. It's on the way. I wish this model existed in the form factor of the PT series stuff. There's such a special feeling of being able to pick a keyboard up effortlessly with one hand and take it anywhere without any second thought. With the bigger keyboards, I tend to hesitate with practicing because I know I need more space. I know the MT-65/68/400v chip is in a few other keyboards. I never looked to see if it's in a PT sized one. If it is, I think that could be the ultimate modification project. Oh... more pipe dreams...

I did one kind of multimeter test to see if the PSU input jack made a full circuit connection and it seemed to be fine if I did it correctly (not confident on that). I have to be honest.. I don't fully understand all the functions of the multimeter yet. I haven't found a good video to explain all the settings clearly and I'm a little bit afraid to experiment if I could cause more damage. I did the beep check function that tests continuity (I think?) and it beeped when I put the leads on the in/out solder points of the PSU jack. That means I don't have cracks under the solder, right? If so, I'm not sure what to do next. I didn't see any cracks on the power switch component with the graphite tracks in the picture I posted and I haven't seen any cracks on the circuit boards. I can't find any components that show visible signs of being damaged either. My only concerns for the moment are : 1) the missing reset button component 2) the graphite traces on the power switch mechanism (is that considered a pot?) 3) the missing tuner trim pot, even though that apparently doesn't matter for powering on(?) When I figure out the right parts to use for replacements, I will move forward with the next level of fault-finding. I'm tempted to take this to a random electronics repair person here in Thailand to see if they can just do it and tell me what the problem is so it's less effort, but I'm afraid the language barrier or a possible misunderstanding of some kind could make matters worse. I'm hoping to learn more from this because I just found an MT-65 locally in excellent condition (with case) for pretty cheap and that means my MT-68 could become a future candidate for isolated output mods for each instrument. But I won't feel confident with that stuff until I conquer this first level of problem solving and understanding electronic components. I imagine I have a very long way to go with this. I've disassembled and reassembled this PT-31 at least 5 times now.

I decided to go a layer deeper to take a peek. I think this is the most beautiful circuit board I've ever seen, though I can't say I've seen many yet. I wanted to ask for opinions about the graphite power control switch. Does it look like there is not enough graphite on there? I really don't know anything about this except for the basic concept of graphite being conductive and being used to complete a circuit. I'm not sure how I should apply the graphite or how much I should put or exactly where. Do I cover each grey block completely or do I just trace the lines that are etched in? Again, thanks in advance, if anyone can help with this.

So.. I was poking around a bit more and I realized there's no component inside where the reset button should be accessed through the hole in the back (see picture). I imagine whoever broke the tuning pot also went crazy poking around in that reset spot too. Maybe they thought stabbing and scraping around would bring the keyboard back to life. I have no idea what that part is supposed to be. Is it even replaceable? Does anyone know what it does functionally? Could that be the reason the keyboard doesn't turn on? Does anyone out there have a service manual for this thing? Also, @Chas - Sorry to bother about it again, but did you happen to find the type of pot that you used to replace your PT-80's faulty tuner? I imagine it's probably the same one. I want to order that part. I am feeling a bit discouraged with this at the moment because it seems like finding the problem is nearly impossible with the limited understanding and resources I have right now. I'm watching a video of someone repairing a VL-1 to better understand the process of problem solving. Does anyone have another useful video resource for visually learning how to repair the more simple keyboards like this? Thanks in advance.

I saw in the YouTube video (posted above) that the guy recommended using a graphite pen to fix things that use graphite traces. Can anyone recommend a product? I'm not completely sure what I'm looking for but I imagine he recommended the pen form of this because it's more gentle for applying graphite than a standard pencil. He said the power switch mechanism was very delicate so I want to find whatever he uses, if possible. I imagine it might be good to have for my MT-400v that has some inconsistent potentiometer issues also. Thanks in advance!

@Chas- I appreciate your responses to my questions! It's nice to know the glue is kind of a standard thing. I don't see any components that look fried or broken but I'm not sure I would know what the tiny clues look like. I imagine they can be very subtle in many cases. I need to do some detective work with a multi-meter but I'll be honest.. I don't know exactly how quite yet. I have one, but it's a bit of a mystery to me at this point. I once used it to check the resistance of some guitar pickups but I've even since forgotten how to do that. Some study will be required.. fortunately, I'm off work for the next week. Anyway, your PT-80 worked without the tuning trim pot? I'm kind of surprised by that. I wonder how it chooses the tuning to stay at without that component telling it anything.. Or... maybe you still had the pot attached (albeit damaged) so it was still bridging that gap in the circuit to keep its functionality(?) I would definitely love to hear about the pot you used. I want to pull the trigger on ordering it so it can get started on its long, slow journey from China. I haven't found the part in domestically for a reasonable price anywhere yet. I'm not sure where else I can go for such a specific thing, especially in Thailand, where lots of shops barely an internet presence or English names to search for. Thank you for the website link. It looks like I can pry the tape memory board up from the inside of the case if I'm careful. This would help a lot with removing everything for easy-access testing and repairing. @pianokeyjoe - Ahh.. you say the tuning pot wouldn't prevent powering on. Guess I'm back to square one on that then. I'm going to try to test with the multi-meter after I have a better understanding of that process from watching videos. I wish I could get the service of someone like you, especially if I could watch the process and learn. That would be amazing. I appreciate the tips with how to manage the layers of boards. I think I've been fairly careful so far, but I don't know how much strain I've put on the LCD. If I get this thing working and the LCD doesn't work, I will be sad. I will try to dig into this further in the next few days after I figure out how to correctly use my multi-meter and I'll see what I can uncover.

I decided I'm not going to give up just yet. I think this is a valuable learning opportunity and I need to accept that I may not get the outcome I want in the end, but I will definitely gain some knowledge from trial and error. I see that the circuit board is labelled 2.2kb.. does this translate to 2.2k ohms? I have found a part that appears to be similar to the one in the PT-30 video. I feel like I'm Sherlock Holmes right now and it's ridiculous.. but I hope I'm on a hot trail with this. I am guessing maybe the 2k version of THIS is what I need as a replacement. I could solder it in place of the missing original. It has the same 3-point triangular arrangement.. but is 2k the same as 2.2kb? I can't be sure I'm fully understanding that part. Even if I fix this bit, I'm not sure if it fixes the power issue. It may not even be related. Side note: The sliders on this PT-31 feel very smooth with their movement. I don't get the idea that they have failed based on feel. Of course, someone could have cleaned and lubed them already with the same hopes I have now. For contrast, my MT-400v's sliders feel quite rough and I get the idea they have been through some abuse, either by the environment, past use, or both combined. I feel like I've rambled too much. @pianokeyjoe- Could you tell me about one of your most difficult - but successful - fixes? I need some hope haha