Massive thank you! I just installed a new belt and tire and the C- gear for a friend. Deck is performing perfect in every way. Did clean the gears and shafts and a drop of oil on the motors. Used synthetic clock grease for the gear shafts sparingly. Wonderful cassette decks these things are. He will be super happy when he hooks it up on his home system.
Great video! Demystifies the issues on this common and popular deck. Great work. Very thorough, well shot, well paced and informative. Thank you very much!
Thanks for the great video. I acquired a 112 MkII for free and it is in mint condition except for the three flashing lights. I took it apart and sure enough gear C was in two pieces. I Just orderded one on eBay. Took less than 10 min to tear it down! UPDATE: I received the gear in 3 days and installed it per this video and lo and behold I now have a fully functional Tascam 112 mkII. Thank You Thank You!
Thank you for this excellent series of videos! Very clear, and superbly detailed. I just got my 122 mk III out of storage, to find the transport doesn't run, so I think I'll be carrying out these repairs myself very soon!
Thank god I found this.. My 122 MKIII has so few hours on it, but it had been sitting in a rack unused for the past 15 years.. Powered it on and tried rewinding / playing a cassette, and got the 3 blinking LEDs of death.. Gear C, I guess?
@@CompactB Fixed THAT, My DA-30 MKII AND My original Blackface ADAT since then! Gear C, Transport loading belt, and Reel Idler wheel, respectively for each.. All three of them are basically pristine other than plastics and rubber perishing. And as far as I can tell none of them need re-caps. The 122 speed sounds rock solid to me. Wish I had a Tascam test cassette tho.
Once upon a time I created my own gear for a NAK deck. Took imprint of broken gear and filled with JB Weld. Years later sill works 100% with no teeth breaking off.
I would also add, for other viewers, that these gears appear to be some type of nylon and/or acetal. You mention in the video that you suspect the grease was the culprit. I concur, and would point out that nylon is a material which is very sensitive to certain trace solvents, such as aromatics and halogens found in some lubricating greases and oils. Nylon will SWELL as well as DETERIORATE when exposed to (for example) lubricants which release acids, as well as wet alcohols and even water. I suspect that the relative amount of torque and temperature exerted on gear C, combined with the heating effect of this load at the bearing surface, all contribute to the eventual failure. If one examines the transport, one can see that Gear C runs fastest of all these driven gears - and by a very substantial margin. This means gear C is the "hot" gear, friction-wise. I have microphotographs showing this, including heat discoloration of the grease on gear C shaft. This, as compared to that on gear B shaft. In my photographs, the lubricant on gear C shaft is obviously discolored from excessive heating, while Gear B is perfectly clear and functional. What's more, the excess lubricant spilled onto the shank of shaft C at unit assembly - lubricant that did NOT run in the gear's bearing surface and did NOT get hot - is also perfectly clean and clear. It looks and feels as good as the day it was put in there. It is obvious from a stereo microscopic examination of this gear drive that the heat of the faster running gear C makes the lubricant do bad things chemically - things that cause then the nylon to be exposed to something released or changed by the heating of the lubricant. Those are things that the very same lube on gears B and A simply does not evidence. The gear C I examined was also swollen onto the shaft, a classic symptom of acid, halogen, or aliphatic solvent exposure for nylon. Anyway, probably more than anyone wants to know. But just know that lubricants definitely do matter on these nylon, acetal and plastic gears.
Hi there, Thanks for the video! It looks like my gear C failed, however there is a tape stuck inside. This prevents the door being removed and thus accessing the mechanism. Is there a way to remove a stuck cassette, when door won't open and basically the whole machine has shut down becuase of gear c failure? I have a Tascam 112 MkII, which shares a service manual with the 122 mkIII, so I'm assuming the methodolgy (if there is one) would be similar. I have tried pushing largest (cam control) gear gently to advance the other gears, but everything is jammed.
While looking on e-bay for the vendor you mention, I found a different vendor that offers a C gear with a brass hub for 10 dollars less. I'm gambling and getting that one. I'll report back if it's any good. My 122mkIII works fine, but I like preventive maintenance. As far as the idler tire goes, I'll probably try something I use called "Rubber Renue" from MG Chemicals. It's a rubber revitalizer. It's worth a shot!
That gear didn't come up on ebay at the time of this video. Looks interesting. Let me know how the rubber renew goes. BTW my 122 Mk III is humming along fine and sounds amazing!
Hi, I have a Tascam 122 MK3, with 0,16% wow&flutter. Changed the pinch roller, but is still the same issue. Is it something to oil/grease there? It could be the idler tyre? Or the SMD capacitors on capstan board?
does anyone know the size or proper name of the black split washer that holds the gears down? I'm trying to order a new one, but don't know the size or name and how to get one
I don't know what grease they used exactly but yes I would say it is probably the fault of the grease used. The parts were deteriorated in the exact places that grease was used but not where it wasn't.
Also, how do you replace the belt on the Tascam 112 MKII. I’ve got the transport out but I’m not sure how to install the new belt. Any help is appreciated.
Hey I have a Tascam 302 tape deck and it will not turn on or do anything. I cant find any info on it or even a replacement power supply. Can you advise me on how to troubleshoot it or where to find a replacement power transformer?
depressing any button [PRRFF] resulted in all3 [Play/Pause/Rec] to simultaneously illuminate. discovered this video but the gears all look ok. any other idea what could cause this??? thank you!!
Jef- They don't necessarily need to break. In my case (Tascam 134B), gear C was still intact, but the grease on all the gear shafts had hardened and was preventing the gears from turning under motor power. You need to remove them, clean all the shafts, and relube. Be careful, I broke gear C by prying up on it, and had to blow 30 bucks to get it back. If anybody knows the true source of all these new eBay C gears, please post it so others don't spend so much.
This one gear is breaking in ALL Tascam tapes that I own, probably made for this purpose as the other gears never broke on any of mine. At least they lasted for some more years than modern gear ;-)
Massive thank you! I just installed a new belt and tire and the C- gear for a friend. Deck is performing perfect in every way. Did clean the gears and shafts and a drop of oil on the motors. Used synthetic clock grease for the gear shafts sparingly. Wonderful cassette decks these things are. He will be super happy when he hooks it up on his home system.
Thanks for watching!
This was what the internet was originally designed for. Excellent helpful information. Perfection.
Great video! Demystifies the issues on this common and popular deck. Great work. Very thorough, well shot, well paced and informative. Thank you very much!
Thank you!
Thanks for the great video. I acquired a 112 MkII for free and it is in mint condition except for the three flashing lights. I took it apart and sure enough gear C was in two pieces. I Just orderded one on eBay. Took less than 10 min to tear it down!
UPDATE: I received the gear in 3 days and installed it per this video and lo and behold I now have a fully functional Tascam 112 mkII. Thank You Thank You!
Thanks for watching!
An excellent presentation. Thanks for sharing. 😊
Thank you for this excellent series of videos! Very clear, and superbly detailed. I just got my 122 mk III out of storage, to find the transport doesn't run, so I think I'll be carrying out these repairs myself very soon!
Thank you!
I have a habit of winning on many different types of repairs thankfully.
Hey here is from JPOSOLARSOLUTIONS, Thanks for this video......
Thank you for the video! Just successfully repaired my unit!! Dreaded gear C!
Thank god I found this.. My 122 MKIII has so few hours on it, but it had been sitting in a rack unused for the past 15 years.. Powered it on and tried rewinding / playing a cassette, and got the 3 blinking LEDs of death.. Gear C, I guess?
yes indeed!
@@CompactB Fixed THAT, My DA-30 MKII AND My original Blackface ADAT since then! Gear C, Transport loading belt, and Reel Idler wheel, respectively for each.. All three of them are basically pristine other than plastics and rubber perishing. And as far as I can tell none of them need re-caps. The 122 speed sounds rock solid to me. Wish I had a Tascam test cassette tho.
Once upon a time I created my own gear for a NAK deck. Took imprint of broken gear and filled with JB Weld. Years later sill works 100% with no teeth breaking off.
Your videos are premo. Thanks again.
Are you a Texan? You sound just like Michael Nesmith. Thanks for the instruction - very helpful.
I would also add, for other viewers, that these gears appear to be some type of nylon and/or acetal. You mention in the video that you suspect the grease was the culprit. I concur, and would point out that nylon is a material which is very sensitive to certain trace solvents, such as aromatics and halogens found in some lubricating greases and oils. Nylon will SWELL as well as DETERIORATE when exposed to (for example) lubricants which release acids, as well as wet alcohols and even water. I suspect that the relative amount of torque and temperature exerted on gear C, combined with the heating effect of this load at the bearing surface, all contribute to the eventual failure. If one examines the transport, one can see that Gear C runs fastest of all these driven gears - and by a very substantial margin. This means gear C is the "hot" gear, friction-wise. I have microphotographs showing this, including heat discoloration of the grease on gear C shaft. This, as compared to that on gear B shaft. In my photographs, the lubricant on gear C shaft is obviously discolored from excessive heating, while Gear B is perfectly clear and functional. What's more, the excess lubricant spilled onto the shank of shaft C at unit assembly - lubricant that did NOT run in the gear's bearing surface and did NOT get hot - is also perfectly clean and clear. It looks and feels as good as the day it was put in there. It is obvious from a stereo microscopic examination of this gear drive that the heat of the faster running gear C makes the lubricant do bad things chemically - things that cause then the nylon to be exposed to something released or changed by the heating of the lubricant. Those are things that the very same lube on gears B and A simply does not evidence. The gear C I examined was also swollen onto the shaft, a classic symptom of acid, halogen, or aliphatic solvent exposure for nylon. Anyway, probably more than anyone wants to know. But just know that lubricants definitely do matter on these nylon, acetal and plastic gears.
Hi there, Thanks for the video!
It looks like my gear C failed, however there is a tape stuck inside. This prevents the door being removed and thus accessing the mechanism. Is there a way to remove a stuck cassette, when door won't open and basically the whole machine has shut down becuase of gear c failure?
I have a Tascam 112 MkII, which shares a service manual with the 122 mkIII, so I'm assuming the methodolgy (if there is one) would be similar. I have tried pushing largest (cam control) gear gently to advance the other gears, but everything is jammed.
While looking on e-bay for the vendor you mention, I found a different vendor that offers a C gear with a brass hub for 10 dollars less. I'm gambling and getting that one. I'll report back if it's any good. My 122mkIII works fine, but I like preventive maintenance. As far as the idler tire goes, I'll probably try something I use called "Rubber Renue" from MG Chemicals. It's a rubber revitalizer. It's worth a shot!
That gear didn't come up on ebay at the time of this video. Looks interesting. Let me know how the rubber renew goes. BTW my 122 Mk III is humming along fine and sounds amazing!
Hi, I have a Tascam 122 MK3, with 0,16% wow&flutter. Changed the pinch roller, but is still the same issue. Is it something to oil/grease there? It could be the idler tyre? Or the SMD capacitors on capstan board?
what benefit will the idle tire provide? mine looks flat and recently my ff and rw don’t want to go 🙁
If the idle tire is not in good condition it will slip during FF/RW.
where can i purchase these replacement parts?
Mine just went out, IDK if the brass hub would help with friction or not. Mine had the larger outer gears go out
does anyone know the size or proper name of the black split washer that holds the gears down? I'm trying to order a new one, but don't know the size or name and how to get one
Would you say this happens as a result of lack of proper lithium or teflon grease ?
I don't know what grease they used exactly but yes I would say it is probably the fault of the grease used. The parts were deteriorated in the exact places that grease was used but not where it wasn't.
petroleum jelly grease from drug store is the best for plastic, but bad for sex.
Also, how do you replace the belt on the Tascam 112 MKII. I’ve got the transport out but I’m not sure how to install the new belt. Any help is appreciated.
Sorry I missed your comment. Sometimes it's like a puzzle to get belts out.
Mình có 1 cái như này bị hư bánh răng mà ở việt nam ko biết nơi mua...!
Can you fix mine please?
Hey I have a Tascam 302 tape deck and it will not turn on or do anything. I cant find any info on it or even a replacement power supply. Can you advise me on how to troubleshoot it or where to find a replacement power transformer?
Great video! I have 2 of these decks, both with bad belts and both with burnt bulbs. Do you have a source for the bulbs? Thanks.
did you ever figure out a bulb solution? I need some for my VUs on my 112MKII
depressing any button [PRRFF] resulted in all3 [Play/Pause/Rec] to simultaneously illuminate. discovered this video but the gears all look ok. any other idea what could cause this??? thank you!!
Jef- They don't necessarily need to break. In my case (Tascam 134B), gear C was still intact, but the grease on all the gear shafts had hardened and was preventing the gears from turning under motor power. You need to remove them, clean all the shafts, and relube. Be careful, I broke gear C by prying up on it, and had to blow 30 bucks to get it back. If anybody knows the true source of all these new eBay C gears, please post it so others don't spend so much.
This one gear is breaking in ALL Tascam tapes that I own, probably made for this purpose as the other gears never broke on any of mine. At least they lasted for some more years than modern gear ;-)
Super super !
Those caps! : (