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I have an old Roland CM-32L sound module. It powers on but no sound comes out. I'm going to try to fix it. I know next to nothing about electronics, so laugh at me while I fumble around destroying it, or maybe help me fix it, whatever you feel might be most entertaining. Either way I'll try to document here. This magazine scan from Jan 1990 is the best promotional shot I can find.  It's an awesome beige beast! Note that the first few posts will be a couple of days behind actual progress, but feel free to warn me not to do dangerous stuff I've probably already done.
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Nov 17, 2021 00:18
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| # ? Apr 19, 2024 18:22 |
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BACKGROUND The Roland CM-32L is a 32-year-old MIDI sound module. It's essentially a clone of the popular (in 1989) Roland MT-32, but with more memory for a few extra effects sounds and without the front panel controls. In 1989 it retailed for about USD 700. When I found mine wasn't working, I figured I'd just buy a new one on ebay for  . However, to purchase on ebay now it's somehow still around USD 350 plus USD 50 shipping from Japan (where they all are) to the USA, or about USD 200 to ship to Australia (where I am).  Some time in the late 90's, or maybe early 2000's, I got this as a hand-me-down from my dad's bedroom studio. Here's mine (obligatory wooden desk shot):  (As you can see from the dirty stains, my dad loves blu-tack. He's an engineer and I'm not sure whether bodging things with blu-tack is exactly what to expect from engineers or whether engineers should Do Better. If I can fix this thing, I'll probably try to properly bleach/clean the chassis.) I wrote a couple of terrible songs built around some of the unique-sounding patches and subsequently lugged this old bit of wonderful junk across the world rather than poorly substitute other instrument sounds from other modules. I'm not sure exactly when it broke, either just before or just after it's last international trip. But since I'm unemployed and can't afford to pay ~800 Australian pesos to get a new one, I thought I might as well try to fix this one. It can't work any less. (Or can it?? Let's find out!) Yes - there is an MT-32/CM-32L emulator that runs on various platforms called MUNT which is really very good. It's hard to tell from the real thing when A/Bing them. However, it's painful to use and there's a big lag between sending a MIDI note and hearing the sound from it, so I've had to offset various tracks to make the timing line up. And I can't use my DAW and have another app output to my audio interface at the same time so I have to pump output from MUNT through my lovely on-board audio output jacks which works about 30% of the time after a windows reboot... etc, etc. I'd really like to have a cool 32-year-old beige box pumping out hissy audio so I can listen to 2 or 3 lovely tracks I wrote 20+ years ago. crusty fucked around with this message at 00:22 on Nov 19, 2021 |
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Nov 17, 2021 00:26
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TRIAGE What works?  It turns on.I know this because the power light comes on. It goes off when I turn it off. I guess "turns on" is a philosophical question - what if only the power LED gets power? Can the device be truly said to be "on"? In my case, it's on, see below. It receives MIDI signals.When I send MIDI data through to it, the MIDI light blinks as expected. Again the philosophical question comes into play... It returns a settings dump when I request it via SYSEX command.Now we're getting somewhere! Even if there's some standalone MIDI comms processor, the SYSEX commands still have to go through at least one chip, some default settings are being loaded from ROM into RAM on start up and then that RAM is being read and sent back out the MIDI port. (I guess - I did Micro Computer Architecture class about the same time I was using this box and that was a long time ago.) What doesn't work?  It makes absolutely no sound.Not from the Mono/L output. Not from the R output. Not from the stereo headphone jack. Not even a little bit of hiss. Not even a little hiss when the volume knob is up to 11. (There is no scale on the volume knob, and since there's no LCD on the front panel to show current volume level, I'm just going to assume 11 is the top value.) It doesn't seem to accept any settings values written to it through SYSEX.I'm less sure about this. All the sysex tools I have are lovely, plus sysex Dump Request Macros (DRM) are pretty common and can be found on the net, but setting values via sysex means crafting custom messages with checksums and maybe I'm loving it up somehow. Since there are no front-panel controls like on the MT-32, and since this module was seemingly built before reverb level was set using controller messages as standard, I can't even adjust reverb type/level until I can write settings using sysex. (I'm a little worried that something more fundamental might be broken if I'm doing the sysex right and this really isn't working.)
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Nov 17, 2021 00:54
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RESOURCES Documentation * MT-32 Service Notes rev 3 * CM-64 Service Notes rev 1 * How to read a schematic (added) Yeah, I can't find a CM-32L service manual anywhere. However, it's pretty much a clone of the later MT-32 models, and the CM-64 is another Roland device that literally has 2 other sound module boards in it, the CM-32L (MT-32 clone) and the CM-32P (U-110 clone). So I'm combining the 2 manuals in lieu of finding the real thing. It's possible that a CM-32L service manual never existed, and the CM-32L, CM-32P, and CM-64 were all release together with the 1 service manual above. (Some evidence for this later). The CM-64 service manual is also hard to find - some guy uploaded it *AS A VIDEO ON YOUTUBE*. Who does this. Yes it's in 4k, but guess what? Turns out those high-detail circuit diagrams still look pretty lovely when you zoom in even after you spend hours using dodgy tools to download a 4k video and then some other buggy tool to dump 4k snapshots from the video file. Luckily, when I was pestering some con artist from one of those "service manual lotto" websites where you pay money for a CD with 500 unrelated manuals on it, he sent me a high-res PDF of 1 page of the CM-64 service manual as "proof" that he had the CM-32L manual I requested. It was the circuit diagram from the CM-32L board of the CM-64 - the only page I really needed in high res - so the con man did not see dollar one. Gear * 1x Multimeter: Etekcity MSR-A600  I assume this is some reference design that is re-badged by 1000 brands. I remember doing research for this purchase, but can't recall if this was "this is the cheapest multimeter I can find that has the word 'multimeter' spelled correctly in the product title on Amazon" research, or "an expert reviewed this and said it was good value for money for an entry-level device" research. * 1x Screwdriver: Stanley 69-189 Multi-Bit Ratcheting Screwdriver I really splurged on this screwdriver getting a Stanley. Rated a solid 5/10 from experts on dontwasteyourmoney.com. * 1x Soldering iron: Tradeflame (no expense spared here)  I assume I'm going to need this and I'm guessing that's when the real fun/damage will start. Electronics know-how * None. This could be a snag. crusty fucked around with this message at 14:12 on Nov 17, 2021 |
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Nov 17, 2021 01:55
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THE TEARDOWN (Apologies in advance for the photos - my Pixel 4a isn't great at closeups.) Let's get this thing open!     So far, nothing obviously wrong to my untrained eye - no melted or strangely brown bits. Some close ups, each quadrant:     Other angles:     Not sure whether lack of visible issues is good or bad. A burnt component would be easy to locate, identify and start fixing, but might indicate some major issue. Eh, I'm going to take this as good news. Some random observations follow...
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Nov 17, 2021 02:43
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Intel inside! Intel P8098 (datasheet). First made in 1982 (from © stamp). Still being used in designs in 1990 (at least). Still working almost 40 years later. Availability: Available used, $20 for 2. Still available unused for $50! e: you know, if I was buying, I think I'd actually want one that has been working happily for 30 years rather than some new one that hadn't done a day's work in its life. Like how SpaceX advertise their used rockets as "flight proven" - I love that point of view. crusty fucked around with this message at 03:30 on Nov 17, 2021 |
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Nov 17, 2021 03:21
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Engineer 1: We want all the noisy components in the back corner, including the main power entry point. But the design team wants the power button on the front. Engineer 2: OK, so we run a cable from-- Engineer 1: How about a reeeeeaaaaaaalllllly long power button? 
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Nov 17, 2021 03:28
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This is interesting: I haven't come across any info that suggests that there were other revisions to the CM-32L. It's likely this board was designed from the beginning to be shared with the CM-64. So it may well be there is no service manual for the CM-32L and the service manual for the CM-64 was expected to be used as the main resource.
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Nov 17, 2021 03:37
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crusty posted:THE TEARDOWN not 100% sure, but the big black electrolytic cap in the upper left hand corner appears to have shat itself (that also might be totally benign adhesive). there also seems to be some corrosion by the green capacitors in the middle of the board. if the board is double sided, you're going to need to take it out and see if there's any damage on the bottom. looks clean though and I wouldn't be surprised that, if the caps are bad, replacing them and replacing a trace or two gets it working. I think IC28 is your audio amp e: or ic 21-27 independently for each channel The Voice of Labor fucked around with this message at 04:02 on Nov 17, 2021 |
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Nov 17, 2021 03:45
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crusty posted:Engineer 1: We want all the noisy components in the back corner, including the main power entry point. But the design team wants the power button on the front. alesis quadraverbs do this too. somewhere there's the ur really long power button that rack synth/fx designers in the 90s all originally ripped off
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Nov 17, 2021 03:47
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This is cool as poo poo and I'm looking forward to the rest of this journey. ALL HAIL LONG POWER BUTTON
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Nov 17, 2021 04:03
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The Voice of Labor posted:not 100% sure, but the big black electrolytic cap in the upper left hand corner appears to have shat itself (that also might be totally benign adhesive). there also seems to be some corrosion by the green capacitors in the middle of the board. Holy moly if you've solved this already - I'd almost be disappointed to cut the journey short! I've been reluctant to take the board out and look underneath just because it's a PITA to undo all the connectors and screws. But I guess I gotta. Next post will have lost of detail on the components and flow.
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Nov 17, 2021 07:21
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The Voice of Labor posted:alesis quadraverbs do this too. somewhere there's the ur really long power button that rack synth/fx designers in the 90s all originally ripped off Finding the original might be a side quest.
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Nov 17, 2021 07:22
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Dammit, don't TIMGs display in the Awful app? All the images on the app are just links. Maybe I should just use normal IMG ETA: It's a setting in the app. Updated some images to TIMG to reduce some scrolling. crusty fucked around with this message at 14:14 on Nov 17, 2021 |
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Nov 17, 2021 07:27
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Noise Machine posted:This is cool as poo poo and I'm looking forward to the rest of this journey. LONG POWER BUTTON, BRINGER OF THE MAGIC BLUE SMOKE
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Nov 17, 2021 07:27
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crusty posted:Holy moly if you've solved this already - I'd almost be disappointed to cut the journey short! yeah, that really doesn't look right and it's right by the amp circuits  don't worry, pulling busted caps without further loving up corroded traces can be all sorts of unpleasant. you're going to need to invest in some desoldering equipment. I use a pump but am getting old enough that a dedicated desoldering rig is looking very tempting. a roll of solder braid is the cheapest but ehnnn. you will probably also want to get a bottle of flux. you will definitely want to get a small roll of LEAD BASED solder. mixing lead free and lead solder is inadvisable. capacitors have two values, capacitance (in farads) and rated voltage. when sourcing replacements make sure the capacitance is the same, rated voltage can be higher than the original but not lower. capacitors also come in several types, those barrels are electrolytic, they're polarized so when you replace them, make sure the leg with the stripe goes in the same way
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Nov 17, 2021 08:01
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THE PLAN* *Plans subject to change based on VoL's feedback! I couldn't find any info on common problems with this device that match my symptoms, so here's my approach: Since all the audio outputs are completely dead, I'm going to work my way back through the logical signal chain starting from the jacks. I'll then test my way up that chain to a "working" component so I know which the first "dead" component is. A simple plan! What could go wrong? Below are the block diagram from the CM-64 (LA Board) and the MT-32. The MT-32 doc contains the actual paths to the jacks (CM-64 version has connectors to join to the other board), but the CM-64 doc has all the correct component labels. CM-64 block diagram:  MT-32 block diagram:  The CM-64 circuit diagram actually has really useful labels too.  (Although it took me too long to realize the "DAC" section was actually 2 chips with quite different functions) The data/audio path is below, as gleaned from the service manuals and datasheets of all the chips I could see. (Note that I'm ignoring reverb paths for now for simplicity - more on that later.) Dark Blue (IC10) LA Chip (Roland proprietary chip) The LA Chip mixes the sound data together based on incoming MIDI, rom sounds, etc. Digital sound data is put on the data bus. Dark Green (IC30) DAC (BB PCM54HP datasheet) Digital/Analog converter. Coverts the digital input (a single sample) to an analog audio output. Red (IC29) OpAmp (M5238L) Amplifier. Boosts the audio signal (a fixed amount?) Orange (IC28) DMUX (HD14051BP) Multiplexer (or is this a de-multiplexer?). Directs the incoming analog audio signal to 1 of 8 outputs as determined by a selector signal. The purpose of this component is clear, but the design is a little weird to me... The CM-32L works using "timesharing", with a set of 8 repeating "timeslots" (3 binary signal lines). There's a clock (timeslot) signal that is sent to several chips so they know what to generate (LA Chip, Reverb chip) or where to direct the current analog audio signal (DMUX). For example:
* In timeslot 6, the current Left channel digital data (sample) is generated by the LA Chip, converted to an analog audio signal by the DAC, and the DMUX dumps the signal on the Left channel path. Light Blue (IC25, IC26, IC27) NJM2082D (datasheet) OpAmp "S/H" Took me a while to get this, but I believe it's "Sample and Hold". Given the timesharing nature of the design, the analog signal isn't always "on"/"set". At the very least, while the Left channel data is coming through the DMUX, the right channel data is not being driven (and there are more than 2 timeslots). So there needs to be some way to "hold" the analog signal until the next value comes around. I've yet to dive into the datasheet for these chips, but this makes sense given what else is happening. I'm ignoring the fact that there are 3 chips (handling 3 different stereo output paths) for now... Pink (IC23, IC24) NJM 4565DD (datasheet) OpAmp Haven't looked much at this, but LPF has gotta be Low Pass Filter to remove some unwanted noise from the top of the signal. Purple (IC20) M5207L01 (datasheet) "VCA" Voltage Controller Amplifier This is an amp with variable gain based on an input. I'm pretty sure this is (indirectly) controlled by the volume knob. I'm guessing this component just reduces the signal based on distance from max (11), and doesn't provide any new gain, but who knows. In the original MT-32, the front panel volume knob controlled the master volume by default, but it also was a value selector for various settings in edit mode. So the knob position/value goes to a chip for processing, not directly anywhere to control an amp. Will analyze separately later. Light Green (IC21, IC22) Gets tricky here juggling MT-32 and CM-64 info. In the CM-64 doc, it's NJM 4565DD (datasheet) In the MT-32 doc, it's M5218P (datasheet) OpAmp From the M5218P datasheet: It is also suitable as a headphone amplifier because of its high load current. So this might have been special processing for the headphone signal (which I assume has a higher level than L/R line outs) but it seems to be in line with the L/R line out audio paths as well, so maybe that's not correct. More investigation required. Yellow (Not actually an IC, just some components) Looks like there are some circumstances where the signal is muted based on a RESET signal from the main chip. It only affects the line outs, not the headphones. I'm not sure when/why this would happen. Summary: - Digital data is generated by LA Chip - converted to analog audio by the DAC - signal is amped a bit before hitting the MUX - MUX sends the value to the correct L/R path based on current timeslot (which feeds both the headphone and line out jacks) - S/H section holds the values current until the next timeslot (?) - Some noise is reduced (LPF section) - Volume adjusted based on volume knob (actually signal from chip which should change based on the knob) - Some additional signal processing (?) - Line outs are muted depending on RESET signal from main chip >> PROFIT crusty fucked around with this message at 14:16 on Nov 17, 2021 |
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Nov 17, 2021 11:51
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The Voice of Labor posted:yeah, that really doesn't look right and it's right by the amp circuits Don't know how I missed that, I guess squinting at the board was less fun than working out how the thing worked. Whoa - it looks like there could be something wrong at *both* of the 2 sets of 2 capacitors: Near the power switch:  Near the output jacks:  Next step: Take the board out and look underneath.
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Nov 17, 2021 12:02
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The Voice of Labor posted:yeah, that really doesn't look right and it's right by the amp circuits This is the good stuff right here...
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Nov 17, 2021 13:01
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Eh...looks ok: (near the output jacks) Hmmm...  Oh.  (From near the power entry.) This is a little strange though. C3 near the power switch looks to be in the worse condition, but many components seem to be receiving power. Based on this diagram:  I'm guessing that there are multiple power rails at different voltages? Looking at the circuit diagram at various places, I'm also guessing that each rail is represented by different symbols. * Normal arrow for 9V * Hollow triangle for 6V * Solid triangle for 5V Am I on the right track? I'm tempted to turn the thing on again (hell, I've been testing it while on for a couple of days) and start testing input voltages for various components to see if there's an issue. I mean it seems clear I should replace C3 at least, but I'd like to know exactly what is not working. (If by some miracle it's still working, I want to fix the real issue first.)
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Nov 17, 2021 14:04
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btw, this page was handy for a quick primer on reading circuit diagrams: https://learn.sparkfun.com/tutorials/how-to-read-a-schematic/all?print=1 I'll add to the earlier docs section.
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Nov 17, 2021 14:11
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crusty posted:Engineer 1: We want all the noisy components in the back corner, including the main power entry point. But the design team wants the power button on the front. WTF
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Nov 17, 2021 21:28
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Hmm, says here that this is the machine that Leisure Suit Larry 3 soundtrack was made with.
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Nov 17, 2021 21:43
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crusty posted:
e: duh, the 7805 is driven by the 9v supply line and, as the chips work, you already have to be getting power. opamps, the things that are usually used for amplifiers, generally take a bipolar power supply, so the +/- 6v rails are for them. the chips on the digital side all probably run off 5v so it's unsurprising that the thing works, but doesn't output sound. if I were you, I would replace the OBVIOUSLY COMPROMISED component(s) before powering it up. even if you're unlikely to break anything else, why bother? if you change the cap out and you get 9v on the 9v line and stuff works you can retroactively infer the swapped component was the problem. you probably already know this or will figure it out soon, but digital synths work like this: digital out->dac->amplifier. once the cap is changed out, if your voltages are all nominal and the thing still doesn't output sound, probing the input and output sides of the dac are next on the troubleshooting flowchart if you want to probe something right now this very minute, plug the power adapter into the wall but not into the synth, put one meter lead in the hole and press the other lead up to the side of the barrel connector and see what it's putting out. you can also check that fused resistor for resistance/continuity and you can do that with everything powered off The Voice of Labor fucked around with this message at 01:12 on Nov 18, 2021 |
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Nov 18, 2021 01:02
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The Voice of Labor posted:
Ok, this is clearly good advice. I was trying to avoid several "order parts - install - test" cycles, but it hasn't worked for some time so what's the rush. Minimizing risk is the smart option. The Voice of Labor posted:
Which resistor is this?
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Nov 18, 2021 01:27
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The Voice of Labor posted:
I do.  I think I tested this previously, but just did it again and got 9.2v.
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Nov 18, 2021 01:32
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petit choux posted:Hmm, says here that this is the machine that Leisure Suit Larry 3 soundtrack was made with. Yep, this is a classy box, no question
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Nov 18, 2021 01:34
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crusty posted:Ok, this is clearly good advice. to avoid piecemealing your order, pick up a desoldering pump or desoldering braid, remove the damaged caps (I'd do the burnt one and 42, 43 for sure) and inspect the adjacent passive components. while you're in there, clean the board (top and bottom) where the capacitors were and around there with rubbing alcohol, check any traces that look compromised for continuity, remove any corrosion, change out any diodes or resistor that look like they got corrosion juice on them. pick up replacements for all the electrolytic caps even if you don't change them now you'll have them. get an extra one for c3 so a spare and get everything over spec (ie, get 25 or 50 volt ones for the 16v ones) they're like 10c each (at least they used to be before supply chains ceased being a thing). resistors and diodes are pennies, transistors are dimes. components are cheap except electromechanical (switches, potentiometers (variable resistors ala volume control), relays) and complex or uncommon ics (which don't, generally, fail). r28 is the fused resistor on the diagram in the dc/dc converter for the -6v output. if you set your meter to resistance, it should be roughly 1 ohm. if it has infinite resistance it is fubar. if you set your meter to continuity/diode you can check every single diode on the board The Voice of Labor fucked around with this message at 02:02 on Nov 18, 2021 |
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Nov 18, 2021 01:49
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crusty posted:I do. o.k.. the 9 volt regulator and dc rectification stuff is all in the adapter, c3 is a smoothing capacitor. weird that it fried and it's not exactly essential, so it failing really shouldn't be the cause of anything else failing. otoh it's directly between the supply voltage and ground so anything shorting out there is going to be bad
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Nov 18, 2021 01:59
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drat, looking at the burnt spot again, I think the case got compressed and the legs of the capacitor arced or shorted on the chassis. after it's all done, put a piece of cardboard or something between the inside of the case and the bottom of the pcb. lol yeah, change out c6 too for sure and the little nonpolar caps around them and check the diode by the really long switch. anything that has a leg corresponding to one of the burn marks needs to go The Voice of Labor fucked around with this message at 02:11 on Nov 18, 2021 |
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Nov 18, 2021 02:06
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Without quoting everything, this info is great. Yeah, I've been looking today at desoldering gun/stations and determining parts and specs to order. Will definitely get enough parts to cover all the large caps and yeah anything else in the blast radius. When I first started thinking about this project I found this Anesty Rework Station ZD-915 which had some good reviews for a cheap device, but that was when I thought it more likely a chip was dead. I'm not sure I can justify this for a few components (even though I just got a new job) but I'll kick myself if I find a dead chip later... Instead I'll probably get something like this HighTop Electric Desoldering Gun There's probably 3mm clearance from the bottom of the pins to the metal plate, and any deformation like that would be noticeable on the casing. Unless it arced somehow, but I imagine that would take a lot more power than is available here?
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Nov 18, 2021 04:52
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crusty posted:
 are the circled bits scorch marks, or discoloration from the corrosive capacitor snot, do they match up with the pins or not? I honestly can't tell without seeing it in person. I also think you might be smarter than I am and as such better suited to make the determination. I could see 3mm flexing down from a drop pretty easily. 9 volts isn't much, granted, but, look, there's a tiny bead of solder at the top of the burn mark, something melted, shorts generate heat. The Voice of Labor fucked around with this message at 06:14 on Nov 18, 2021 |
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Nov 18, 2021 06:10
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I wonder if tayda electronics still has a goon discount code. it's also totally possible to get by with a $10 desoldering pump if funds are tight. you'd probably be better off putting money on a better iron with a base and adjustable temperature The Voice of Labor fucked around with this message at 07:09 on Nov 18, 2021 |
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Nov 18, 2021 06:56
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The Voice of Labor posted:are the circled bits scorch marks, or discoloration from the corrosive capacitor snot, do they match up with the pins or not? I honestly can't tell without seeing it in person. Sorry about the lovely photos! At least one of the spots matches up with a pin, but yeah, there's no way it touched - there are two support posts either side of the power jack right nearby and I can't imaging even being able to bend it down there if I wanted to. I think the marks are just the crud dripping down after the Big Bang (or Big Melt or whatever they do). I'll replace anything that looks like it has a spot under any of its pins. The Voice of Labor posted:I also think you might be smarter than I am 
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Nov 18, 2021 12:41
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Yeah, I think I'm going to pull the trigger on one of these tomorrow... HighTop Electric Desoldering Gun  Pros: * Has some user ratings, some of them even might be real Cons: * Arrive ~4 weeks * Sent international - all intl shipping estimates are lies right now * US 110v - I have a transformer I use for all my other US gear, but I'd rather not have to worry about where to plug it in. MiZOELEC Electric Vacuum Solder Sucker  Pros: * Sent from Australia (220v) Cons: * Arrive ~3-4 weeks * No ratings - I love being a trailblazer for cheap gear DuraTool Desoldering Pump 230V  Pros: * Claims delivery in ~2 weeks * Very cheap (AUD $46 for 1-2 week delivery) * Hey ladies!  Cons: * Shipped from the UK * Manual pump like I'm some pleb who has to pump my own solder
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Nov 18, 2021 13:58
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You are doing great and I think you've motivated me to spend yet more money on soldering equipment. When I first saw that I was like, yeah, somebody stepped on that thing while it was on, but you're probably right, looks impossible. I guess you have no specific recollection of when it did this, else you would have mentioned it by now. I doubt this actually caught fire but it def made some fumes when it went. crusty posted:Yeah, I think I'm going to pull the trigger on one of these tomorrow... Yeah, I've neglected this in my electronics kit, I'm getting one too and i appreciate you doing my shopping for me! Be cool.
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Nov 18, 2021 15:12
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Cool thread hope you fix it
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Nov 19, 2021 00:12
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petit choux posted:Yeah, I've neglected this in my electronics kit, I'm getting one too and i appreciate you doing my shopping for me! Awesome, if anyone saves some time by reading I'll consider this thread a triumph. And if you get something and it's poo poo/great, let me know and I'll add warnings/kudos to the post!
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Nov 19, 2021 00:18
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I dunno, parsing out that a serial dac is being run through sample and hold circuits to get stereo channels while never having thought about it before is a pretty tough piece of inferior smartness to defend I bet you're such a nerd you're going to look at the clock frequency and the demux/ s/h circuits and figure out what the effective sample rate is. and I bet you're going to use math to do it. then you're gonna figure out how the reverb circuit works and clone it into a stompbox telling you though https://www.amazon.com/Weller-7874B-ESD-Safe-Desoldering-Aluminum/dp/B00DKYNKPK and something like this https://www.amazon.com/Weller-WLC100-40-Watt-Soldering-Station/dp/B000AS28UC it's real nice to have your iron rest when you're not using it, a lot safer too and it's real nice to be able to adjust the temperature
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Nov 19, 2021 01:31
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Cool av, I did a GIS but couldn't see it. What's it from? The "visually similar" link from that returns a pretty cool page.
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Nov 19, 2021 01:32
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