New to me MCI JH24 - stupid annoying problem

Miro that’s what I was thinking too. It’s a switching function that’s not happening automatically, but I’m thinking dancer arm adjustment. Me being able to see what’s happening when Sean manually rotates the takeup reel when the transport is in faulty PLAY would be helpful.

Sean, again, thanks for the effort with the video, but somehow you interpreted the “dancer arm” to be the arm that’s down inside the transport. The dancer arm is the tension arm you are pushing on to get the transport to PLAY.

I need to see what that thing does when the green PLAY light is lit, but the transport isn’t moving tape, and you manually rotate the takeup reel counter-clockwise, just like at 6:10 in your previous video. A 10 second video will do. Maybe make sure we’re understanding each other before you take time to shoot another video.
 
I don't know if you've already done this...but when I first got my MX-80 (used), I plugged it in and did the basic power up...but then before I go into any more usage of the deck or trying it with tapes and all that...I took most of it apart and cleaned it.
Not down to every screw "apart"...but certainly every electronic connection front, back and inside. I mean, every cable connector that was used for either audio or electronic control of the deck. I also clean all the moving parts and anything that was easy to open or take apart without having to use tools, unless they were to remove a cover or something.

IOW...I left the motors and headblock and many of those things in place, but cleaned all around them and cleaned anything that was an easy disconnect/connect piece...so there was little riskiness of damage, but the deck was basically overhauled and cleaned from top to bottom>
I also removed and cleaned EPROM chips and all the connection points on all the PCBs....etc...ever audio card was pulled...etc.
I think I spent a few days to a week on and off doing that...so it took a while, but I didn't want to start diagnosing any perceived performance "problems" until I did that, because with a deck that sits for a few years...oxidation is a bitch. Not to mention...all the mechanical stuff, and the things that have some sort of grease or oil on them...al that will get a bit "stiff" from not getting used.

I was also told by an Otari tech to not let it sit too long without power it up...that doing so would only increase the potential for problems.

So if you have given it a good cleaning overhaul...may be do that...and then run some tape, use it, see if things improve with cleaning and some use.
In the end, it may just be some switch or sensor that will need to be adjusted or replaced...but at least you will be testing a machine that is free of oxidation and stagnation. :)

Speaking of which...I need to fire up my MX-80 soon. Been laying around for a few months now with any recording being done...just too many other things got in the way.
 
Now I don't know JACK about that machine but the lamp supply issue will I bet be a popped medium power switching transistor (googe "BD131, TIP41") and/or its base drive components.

I HAD thought the 'non-starting' could be a dead spot in a motor but as the story evolved fortunately not.

Mir's clean up advice is good but I would NOT pull any chips especially 'digital' types. Static destruction is much rarer than often made out but why risk it? (says he, living in leafy,damp England!) .

And yeah "If ain't broke......" does not quite apply but there is always the danger of 'finger trouble' and further damage. Like my speedo, old and quaint, I just keep thumping it.

Oh! And yes, check your mechanical gear regularly. My excellent Sony Dolby S cassette deck was unloved in an unheated room for 12 months. Tried it 3 days ago and the capstan belt had 'melted' . Replacement came yesterday but this one eyed, shaky old tech has got to summon up the courage to tackle the job. Gladly PAY someone to do it, nobody left these days I trust.
Dave.
 
I don't know if you've already done this...but when I first got my MX-80 (used), I plugged it in and did the basic power up...but then before I go into any more usage of the deck or trying it with tapes and all that...I took most of it apart and cleaned it.
Not down to every screw "apart"...but certainly every electronic connection front, back and inside. I mean, every cable connector that was used for either audio or electronic control of the deck. I also clean all the moving parts and anything that was easy to open or take apart without having to use tools, unless they were to remove a cover or something.

IOW...I left the motors and headblock and many of those things in place, but cleaned all around them and cleaned anything that was an easy disconnect/connect piece...so there was little riskiness of damage, but the deck was basically overhauled and cleaned from top to bottom>
I also removed and cleaned EPROM chips and all the connection points on all the PCBs....etc...ever audio card was pulled...etc.
I think I spent a few days to a week on and off doing that...so it took a while, but I didn't want to start diagnosing any perceived performance "problems" until I did that, because with a deck that sits for a few years...oxidation is a bitch. Not to mention...all the mechanical stuff, and the things that have some sort of grease or oil on them...al that will get a bit "stiff" from not getting used.

I was also told by an Otari tech to not let it sit too long without power it up...that doing so would only increase the potential for problems.

So if you have given it a good cleaning overhaul...may be do that...and then run some tape, use it, see if things improve with cleaning and some use.
In the end, it may just be some switch or sensor that will need to be adjusted or replaced...but at least you will be testing a machine that is free of oxidation and stagnation. :)

Speaking of which...I need to fire up my MX-80 soon. Been laying around for a few months now with any recording being done...just too many other things got in the way.

Thanks, Miroslav. This makes good sense. I'll take some time and do that. I'd _so_ hand it over to a tech to a tech to straighten out at this point, but in this area, I appear to be it. It cost me a fortune just moving it forty miles, so it'd have to be someone who makes house calls or who can have me send him cards, etc.
 
Now I don't know JACK about that machine but the lamp supply issue will I bet be a popped medium power switching transistor (googe "BD131, TIP41") and/or its base drive components.

I HAD thought the 'non-starting' could be a dead spot in a motor but as the story evolved fortunately not.

Mir's clean up advice is good but I would NOT pull any chips especially 'digital' types. Static destruction is much rarer than often made out but why risk it? (says he, living in leafy,damp England!) .

And yeah "If ain't broke......" does not quite apply but there is always the danger of 'finger trouble' and further damage. Like my speedo, old and quaint, I just keep thumping it.

Oh! And yes, check your mechanical gear regularly. My excellent Sony Dolby S cassette deck was unloved in an unheated room for 12 months. Tried it 3 days ago and the capstan belt had 'melted' . Replacement came yesterday but this one eyed, shaky old tech has got to summon up the courage to tackle the job. Gladly PAY someone to do it, nobody left these days I trust.
Dave.

Thanks, ECC. I had similar problems with a couple of inherited Tascam cassette decks. The VU lamps are worth more than the machines now.
 
So, no real definitive answers for you at this point, but I really really want to encourage you spend some quality time with the manual. It might seem grade-school at this point, but section 2 of the manual walks you through each of the functions. You are supposed to test each function as laid out in the manual. It will answer some of your functions/features questions, and may even reveal clues to the source of your troubles if you find things aren’t operating as described in the manual. I highly encourage you to discipline yourself to walk through section 2 as advised by the manufacturer. This was SOP for an owner upon delivery of the machine.

I also *highly* encourage you to, as previously suggested, excercise connections/ensure positive interconnect, and do the transport adjustments/checks in section 7 of the manual, particularly sub sections 7 (dancer arm), 8 (brakes) and 9 (tension). It looks like the supply reel and takeup reel rock slightly clockwise when you engage STOP, but the takeup reel moreso allowing the dancer arm post to move to the right, which suggests to me there is either too much holdback tension, or not enough takeup tension being applied in the STOP mode with tape loaded. It is a constant tension system, but it has three modes: STOP, PLAY and fast-wind and different tension setting in each state, but in each state there is supposed to be equilibrium between both reels applying equal and constant tension to all points of the tape. It doesn’t look like that’s the case in STOP mode...it shouldn’t move or creep in STOP. So...this is what I would look at, BUT FOLLOWING THE PROCEDURES IN THE MANUAL FIRST SO I WAS FAMILIAR WIH THE MACHINE, CONTROLS AND FUNCTIONS, AND THEN DOING THE ADJUSTMENTS/CHECKS IN ORDER AS MCI PRESCRIBES. Not yelling...caps for emphasis.

Regarding your issue with the lamps, there are two power supply units, one for the transport and servo systems located in the “right side of the transport cabinet” and the other for the audio, relays and logic. It is located in the “left side of the transport cabinet.” See section 6.3 of the Manual for the description of this supply. It has a fuse holder plug which I believe houses the main fuse F1 for that supply. Section 6.3 indicates there are also 3 more fuse holders mounted to the front panel of the power supply. These are the fuses that protect the +/-18V audio rails (F2 and F3), and +24V relay and logic supply (F4). You’ve been focused on finding F3 and now I’m wondering why...that’s audio related. You are looking for F4. But, as I mentioned earlier I don’t think this is your problem because if F4 was blown NONE of your logic or relay switching would work...or your lamps.

There is an Interface/Lamp Driver board (schematic 3-25) that I believe powers the meter lamps along with status lamps (I believe...still not certain...have to study the system interconnect schematics and look for the relay switching board schematic) but I think your issues are going to be with component failure somewhere...in...there.
 
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Hey Cory,

Thanks again. I too found that Lamp Driver board mentioned in the manual, and located where it was on the motherboard. It's one of the few that looks like it's not been replaced:
This is a pic from Studio Electronics' site, but mine looks just like this, except one of the handy zip ties, which are apparently to facilitate pulling it out, is broken on mine.

IMG_0031 by Sean Kerns, on Flickr

Of course I don't see anything that looks barbecued on there, but it's never that easy. I could pull it and check caps and resistors. The chips are a different story. I do see that studio electronics has had these in used for not a lot of money. If I could find one, I'd gamble the money to try it, because that's my bet, too.

I am working my way through the manual. That's where I started in figuring out what buttons did what.
I'm going to try to follow the transport and tension setup stuff in the manual, as much as I can with screwdrivers and a multimeter. There is a troubleshooting section for it in ch 8, but most of the fixes are to "check IC__". Not super helpful. But probably the whole transport setup needs to be done. I did notice a kind of wobbling/shuddering noise sometimes when starting playback, and once or twice, especially after I'd tipped the table back to look at something on the PC boards, I'l see it creeping a little in stop. I also noticed that the tape on the takeup side was rubbing the reel about once per revolution, which it was not doing when I got it. I am thinking maybe some adjustment came loose there. So again, where I can, I plan to do the setup.

As for PSU's, there are three of what I would refer to as PSU's on the back of this. Two on the bottom of the cab, L and R:

IMG_0031 by Sean Kerns, on Flickr

The one on the right has just a voltage selector/fuse housing on the back, like the one on the lower left of the left PSU.

The left one, here:

IMG_0031 by Sean Kerns, on Flickr

That one has another of the giant holders and three smaller ones. There are several large connectors on the top of it, in addition to the one you see just to the right of the fan. I _believe_ I checked all three of those smaller fuses, but I'll look again. They're very unhelpfully not numbered.

IMG_0035 by Sean Kerns, on Flickr

Now, in the middle part of the cabinet, there are two other enclosures. On the left is where the three big plugs for the autolocator, capstan servo programming, and the third one on the right, not labeled. I can see these connectors come from three of the six cables to the autolocator. Those connectors love to unplug when you tilt the reel table back, and make you think your autolocator has stopped working. Fun. That's the takeup reel motor you see behind it.

IMG_0035 by Sean Kerns, on Flickr

Then over to the right side, there is this one, which has connectors for "deck", audio", two outputs for fans, the receptacle for the wall power, and those two nicely labeled F1 and F2 fuses, both of which are good. Feed reel motor is seen behind it:

IMG_0031 by Sean Kerns, on Flickr
 
By all means, if you want to just buy some new parts and swap-n-see what happens...it won't hurt anything, it's just a cost/time issue.

That said...I would think if there was an electronic component issue, you would never get the thing to click into Play...but instead it does it sometimes, and always when you give it the lightest touch.
So I would still start by cleaning, deoxidizing, working the parts, and lubricating as needed.
I think once you start just swapping out parts, you could go down a longer road, only to find no solution still or that the solution didn't involve any of the new parts, and was tied to something else.

I guess I'm just really adamant about a really good cleaning before trying to diagnose any issues. I wouldn't even power it up anymore.

I'm have a similar situation as you...
I recently picked up a 1/4" 2-track, an Ampex ATR-102 (actually got if for free), from a theatre that was ready to roll it to the dump, simply because they had not used it in 15-20 years, and they needed to clear out a large storage area for some other purpose, so a lot of their old equipment was going to get tossed, and they decided there was no point in keeping the deck regardless if it worked or not, and they were not in a position or showed any interest trying to sell it. They just needed out fast...and there I was to claim it. :)

So when I first got it, before we even rolled it out of the theatre, I figured let me just see if it lights up...and I plugged it in, and it did, but right away I could smell the years and years of dust and oxidation being burned off somewhere in the electronics, so I quickly yanked plug.

That deck will not see power again until it gets a complete cleaning overhaul...something I intended to be doing over these winter months, but I'm sidetracked with other things, and I don't really need the deck for anything (I have a practically brand new 1/4" 2-track Otari 5050 BIII...last model ever made).
I'm actually trying to decide if I even want to keep it the Ampex. I might just do the overhaul, make sure it's all running...and then sell it off, since it's a space hog...but I will fist see how it sounds! ;)
Anyway...it would silly of me to start troubleshooting a machine that needs to be cleaned, deoxidized, lubricated...etc.
 
When I’m talking about replacing the board, I’m actually talking about the problem with the meter lights. That little board has about 20 ICs on it, and at least as many resistors and capacitors and diodes, and so I’m assuming it would be easier in that case to just swap in a new one if I can do it.
 
Your issue with the reel rubbing may be a tweaked reel flange. Don't go adjusting the reel table heights based on that. Look to see if the tape pack is centered on the reel hub. That's how you tell if the reel table height needs adjusted. Otherwise swap the tape to a different reel or try to tweak the existing one.

If you are having issues with multipin connectors becoming disconnected when you tip the transport up...THEN DON'T TIP THE TRANSPORT UP WHILE ITS POWERED...and verify positive connections before applying power. I'm telling you...assume there is NOTHING connectorized on that machine that should be disconnected or reconnected with power applied...permanent damage can and will occur.

Those two upper boxes, I'm not sure which is which and that's irrelevant at the moment. There are only two power supplies, both at the bottome, the audio/relay/logic/lamp supply is on the left, the transport/servo supply is on the right.

On the left supply F1 is the larger fuse at the bottom of the column of fuses, F2 is the +18V labeled fuse, F3 is -18V labeled fuse, and F4 is the +24V labeled fuse. Again, just sayin' if one of these fuses was blown you'd have a whole lot more not working.
 
Your issue with the reel rubbing may be a tweaked reel flange. Don't go adjusting the reel table heights based on that. Look to see if the tape pack is centered on the reel hub. That's how you tell if the reel table height needs adjusted. Otherwise swap the tape to a different reel or try to tweak the existing one.

If you are having issues with multipin connectors becoming disconnected when you tip the transport up...THEN DON'T TIP THE TRANSPORT UP WHILE ITS POWERED...and verify positive connections before applying power. I'm telling you...assume there is NOTHING connectorized on that machine that should be disconnected or reconnected with power applied...permanent damage can and will occur.

Those two upper boxes, I'm not sure which is which and that's irrelevant at the moment. There are only two power supplies, both at the bottome, the audio/relay/logic/lamp supply is on the left, the transport/servo supply is on the right.

On the left supply F1 is the larger fuse at the bottom of the column of fuses, F2 is the +18V labeled fuse, F3 is -18V labeled fuse, and F4 is the +24V labeled fuse. Again, just sayin' if one of these fuses was blown you'd have a whole lot more not working.

I agree that the meter thing is probably not a fuse, esp. since I've checked those. And I think you're right, way more would not be working. My money is on having cooked a component or more than one on that lamp driver board. I'm leaving that alone until or unless I can find a spare to try.

I found out about the connectors unconnecting when I tipped up the transport entirely accidentally, like many other things on this machine.

I bolded and unerlined the part about not connecting or disconnecting anything while the machine is on, so that I remember it.
 
So, two more general questions:

- On a machine this age, assuming that I don't care what it costs to run it, should I just leave it on 24/7 when I'm using it? I've had some older machines just lose their mind and things get gummed up when not powered on for a while, and it does seem like this needs to "warm up". Then I have also had machines that would just start misbehaving if left on too long. But generally, it seems like the cold to hot transition really stresses older gear. My Dad had a superstition about not ever turning off his studio gear, because every time something failed on him, it was on startup.
Also, possibly relevant, this room is only kept about 68-70 degrees F year round.

- Am I inviting problems, or is it a good idea (with the power off) to go through and just disconnect and reseat all of the molex connectors? And maybe the channel cards?

I'm a little shyer about the daughter boards inside the cabinet. I'd bet I have some gunky connections, but man, these seem fragile. I'm afraid of hurting more than helping there.
 
I agree that the meter thing is probably not a fuse, esp. since I've checked those. And I think you're right, way more would not be working. My money is on having cooked a component or more than one on that lamp driver board. I'm leaving that alone until or unless I can find a spare to try.

I found out about the connectors unconnecting when I tipped up the transport entirely accidentally, like many other things on this machine.

I bolded and unerlined the part about not connecting or disconnecting anything while the machine is on, so that I remember it.

There's more to the lamps than the driver board...there is a relay and logic board too. You're welcome to purchase used spare boards if you wish, but it might be worthwhile to see if the probable cause can be narrowed down first...but I don't know when I'll necessarily have time to become further acclimated with the manual and the machine. It takes time to learn the language of how the schematics and wiring diagrams inter-relate...the specific manufacturer's documentation conventions...especially on a machine as complex as a servo-based open reel multitrack machine with an integrated autolocator. I can't do that hopping around a PDF...I need to have the paper...and then I just have to stare at it a lot.

I put my money on a roached logic IC.
 
So, two more general questions:

- On a machine this age, assuming that I don't care what it costs to run it, should I just leave it on 24/7 when I'm using it? I've had some older machines just lose their mind and things get gummed up when not powered on for a while, and it does seem like this needs to "warm up". Then I have also had machines that would just start misbehaving if left on too long. But generally, it seems like the cold to hot transition really stresses older gear. My Dad had a superstition about not ever turning off his studio gear, because every time something failed on him, it was on startup.
Also, possibly relevant, this room is only kept about 68-70 degrees F year round.

- Am I inviting problems, or is it a good idea (with the power off) to go through and just disconnect and reseat all of the molex connectors? And maybe the channel cards?

I'm a little shyer about the daughter boards inside the cabinet. I'd bet I have some gunky connections, but man, these seem fragile. I'm afraid of hurting more than helping there.

I dunno...if you don't care about the electricity and the heat generated, I guess you can just leave it all on. That's what most big studios do...partly because they are always working and busy, and I also because of keeping the gear "stabilized" at the same operating condition...none of that power up/down.

I've got too much gear to afford keeping all on...and I simply don't use it day in and day out, or I may only use one small part of it on a given day, so keeping my console and decks and all my rack gear running with be wasteful, and in the warmer months, even with the cooling I have in my studio, all that gear would push up to temps. In the winter it might actually keep the room warm without running the heat. :)

It's you decision, and really hard to tell how it would affect an older piece of gear like that...on or off? Like I mentioned earlier, the Otari tech suggested I no leave my MX-80 powered off for real long stretches. He just said it will help keep the deck from misbehaving and tossing up error codes on start-up....but there was never any suggestion to just keep it on all the time.
You might hit some of the MCI web boards and see what others are doing with their decks.
 
There's more to the lamps than the driver board...there is a relay and logic board too. You're welcome to purchase used spare boards if you wish, but it might be worthwhile to see if the probable cause can be narrowed down first...but I don't know when I'll necessarily have time to become further acclimated with the manual and the machine. It takes time to learn the language of how the schematics and wiring diagrams inter-relate...the specific manufacturer's documentation conventions...especially on a machine as complex as a servo-based open reel multitrack machine with an integrated autolocator. I can't do that hopping around a PDF...I need to have the paper...and then I just have to stare at it a lot.

I put my money on a roached logic IC.

Yes, as do I, and I agree with the approach of finding and fixing bad components, but I don't have either the skill or equipment to diagnose a bad IC except by swapping them out. And then if I have two... my approach only works if I replace them all or get lucky and only have one out.
 
I dunno...if you don't care about the electricity and the heat generated, I guess you can just leave it all on. That's what most big studios do...partly because they are always working and busy, and I also because of keeping the gear "stabilized" at the same operating condition...none of that power up/down.

I've got too much gear to afford keeping all on...and I simply don't use it day in and day out, or I may only use one small part of it on a given day, so keeping my console and decks and all my rack gear running with be wasteful, and in the warmer months, even with the cooling I have in my studio, all that gear would push up to temps. In the winter it might actually keep the room warm without running the heat. :)

It's you decision, and really hard to tell how it would affect an older piece of gear like that...on or off? Like I mentioned earlier, the Otari tech suggested I no leave my MX-80 powered off for real long stretches. He just said it will help keep the deck from misbehaving and tossing up error codes on start-up....but there was never any suggestion to just keep it on all the time.
You might hit some of the MCI web boards and see what others are doing with their decks.

Well, ostensibly, this is a piece of gear I might not use for months, and then I might need it for a week or two solid. I'm thinking leave it on for that week or two, then off if I'm not going to use it again for a few months.
 
Now, stuff like my guitar amps, keyboards, things like that absolutely, those get turned off. If I'm not using them for more than a few hours.
 
So, two more general questions:

- On a machine this age, assuming that I don't care what it costs to run it, should I just leave it on 24/7 when I'm using it? I've had some older machines just lose their mind and things get gummed up when not powered on for a while, and it does seem like this needs to "warm up". Then I have also had machines that would just start misbehaving if left on too long. But generally, it seems like the cold to hot transition really stresses older gear. My Dad had a superstition about not ever turning off his studio gear, because every time something failed on him, it was on startup.
Also, possibly relevant, this room is only kept about 68-70 degrees F year round.

- Am I inviting problems, or is it a good idea (with the power off) to go through and just disconnect and reseat all of the molex connectors? And maybe the channel cards?

I'm a little shyer about the daughter boards inside the cabinet. I'd bet I have some gunky connections, but man, these seem fragile. I'm afraid of hurting more than helping there.

Well, Sean, these are good questions...you don't qualify what "when I'm using it" means. If it was me, and I was going to be using it a chunk in the morning, and chunk in the afternoon and a chunk at night on a given day (for instance), I'd power the sucker up 30 minutes before it was go time and leave it on until I was done that night. If the night went late and I was going to be using it again in the morning I might just leave it humming. If I was a busy studio and had sessions going 5-6 days a week throughout the day and evening I would probably leave it powered all week, give it a rest on the day off. If I was going to use it during an afternoon and then not for days or more after, I'd power it up ahead of time and shut it down when I was done that afternoon.

Hope that helps.

Yes its the in-rush current upon power-up that stresses components as well as thermal expansion and contraction. In my opinion the issue isn't really how long its powered up or how long its powered down, but rather how frequently it is powered up and down. There are exceptions to this of course (such as programmable logic ICs that benefit from being routinely powered and not left un-powered for long intervals). Good circuit designs will take into consideration the in-rush current and have components effected by this appropriately spec'ed, but, *everything* wears out eventually. Many, many components last a long, long time...a lifetime even. The other wrinkle to the thermal issue is considering if a unit employs good thermal management. This is a major caveat to leaving a unit powered for extended durations. If there is poor thermal management and stuff gets really hot, then you either have to augment the cooling measures or power it down to cool. But, here again, a good design takes these things into consideration. My Ampex MM-1000, being essentially a kludged 2" quad video machine, has crappy thermal management...it wasn't designed from the ground up as outfitted. Your JH-24 was, and the power supplies (the prime facets needing good thermal management) on the MCI stuff have a nifty "chimney" type cooling fan arrangement with output transistors mounted in the chimney (for instance)...they thought it through. I wouldn't be concerned about leaving your machine powered if that's what suits you when you're using it. I think of it this way...if something on the machine is in such a fragile state its going to croak because I'm powering the machine frequently or leaving it on for extended periods then let it croak so I can fix it, and maybe with a better spec part...if its that bad its death-rattle was possibly causing other issues anyway.

Not sure what your concern is about "68-70 degrees F year round"...sounds like a good environment.

I would say it IS a good idea to re-seat the connectors, not just the Molex, but the Cinch Jones and other connectors on that machine, AND re-seat cards...and press on socketed ICs. All this stuff when it sits has the potential to oxidize depending on the base material of the connection and the plating, and (hopefully not) especially if two incompatible metals are mated. Pressing on those socketed ICs (while supporting the underside of the socketed site) will often result in tiny little clicking, snapping or crackling sounds...that's the sound of enhanced or renewed contact. The cable mount and card connections are connectorized because they are INTENDED and DESIGNED to be reaseated. So do it. Be careful and gentle as you do it. Look at the connector or card first and analyze the best way to pull it. In some cases the manufacturer has figured that out for you (like those zip-tie handles on your lamp driver board), or there are holes for attaching a home-fashioned bale to pull it. Sometimes there is an in-built lever to pop the card out...that's always nice. But ALWAYS refer to the manual to avoid pitfalls just in case, and ALWAYS feel free to look online or post questions if there's a stubborn card and you are worried. We might be able to advise or at least encourage. I believe all the boards on the JH-24 are made from glass fiber of decent thickness as opposed to the more fragile phenolic resin in some other gear that is also often thinner. These are considerably more robust. If you ever have totally dispensable spares of this type of board, just try breaking it by hand to get an idea of how strong they can be. And when all else fails, you can always (and sometimes its a good idea) to re-flow the solder joins of board connectors. And it never hurts to wipe on or spray on some DeoxIT D5 to those connections. It will enahnce and protect the connection and make reseating/reconnecting easier...good preventative maintenance.

The most stubborn cards I ever had to pull were out of a Tascam 388...the record/play amp cards...thin phenolic resin boards and MAN were they stuck. Ultimately I made a bale out of copper wire and threaded it through holes that are in each corner of those boards and strategically rested my wrists on the edge of the cardbay and patiently pulled one side then the other in a careful rocking motion. Got each card free without incident that way. I did inspect the motherboard pin solder joints as well as the connector socket solder joints on the cards, and applied DeoxIT D5 a re-seated a few times...no issues...just had to be smart and take it slow and steady. And again these were the more fragile phenolic resin boards and they were in there TIGHT. Remember: they are connectorized because they are intended to be pulled for service.
 
Thanks, Cory. The 68-70F thing wasn't a concern necessarily as much as data. I control humidity, too. I've got lots of fragile acoustic instruments, a piano, things like that. Most of my gear seems to live pretty happily in those conditions - guitars, amps, outboard gear. Some of my cats think it's a little cool.

And thanks for the affirmation on reseating stuff. I'm trying to prevent, not cause problems. Reseating stuff seems like a good idea, but wanted to see what you guys think.

Your mention of re-flowing solder reminded me of my original Tascam 38. All the channel boards are soldered to the motherboard on it (if I remember correctly from when I did this ~15 years ago), and some of the connections had cracked. I started losing playback, and then recording on some channels. And I only had 8 to start with on that. I ended up spending an entire week with a magnifying lamp, reflowing every connection on that thing. Worked great afterward.
 
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