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TEAC A-4010S Stop button issue

WiDucPioneer

WiDucPioneer

Member
I recently purchased a TEAC A-4010S from a seller who has a lot of experience refurbishing old TEACs. Mechanically it's in pretty good shape, it's clean, had been lubricated and has serviceable belts. Electronically it's kind of a disaster. I think it's in desperate need of a recap. Bass and low frequency content records and plays back distorted. Highs sound ok. The only way I can get a clean recording is to record at extremely low levels and even then it's not that great. I'm hoping recapping the record and playback boards will take care of the distortion issue. I also plan to replace all the Suzuki .1 uf caps. None of them have popped so far fortunately.

The problem that baffles me is that the Stop button stops working after about 15 minutes of operation. The shut-off lever can be actuated to stop the machine but the Stop button becomes inoperative. The micro-switch works fine and there is nothing else obviously wrong. It seems like a heat-related resistance problem but I can't seem to track it down. The temperature of the big wire-wound resistors near the top of the case correlates with the operation of the Stop button. When the resistors cool down to just warm from hot the Stop button starts working again. I understand it's normal for these resistors to get very hot and there is nothing else affected like the speed of the motors. I'm considering the temperature of the resistors to be just a barometer of whether the Stop button will work or not. Could the Suzuki cap associated with the Stop button be the cause? It's not open but I have not taken it out of circuit to check the capacitance of it yet.

Just wondering if anyone else has experienced this issue?

Thanks in advance for any feedback.
 
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replace all those .1mf caps immediately. about 13 of them. I believe there is one across the stop button, it's probably shorting out when heating up. The large resistors on top are for motor back tension, not related. As for sound quality, what tape are you using? old stock maxell works very well with them.
 
Thanks for the response. From reading posts here I immediately thought about the .1 mf Suzuki caps being the culprit but they are not getting warm or are even near any source of heat so I thought maybe there was something else going on. I posted here to see if anyone else had encountered this issue. I realized from the schematic that the large wire-wound resistors are there to mediate tape tension. It's just when they cool down the Stop button works again although there is no connection to the tape direction switches. So, in effect, the resistors are just an unconnected indicator of when the Stop button will work again.

I am using modern AMR-MDS36 tape but I have an old tape that came with the unit and I bought a reel of NOS 3M Scotch 806 tape and I am getting low end distortion on all types. I am hoping recap of the record and playback boards will resolve the issue. If it sounds better after the recap I plan to take it to a well-regarded R 2 R repair facility to have them adjust the EQ circuit where evidently a few capacitors can be swapped out with different values so the unit will sound good with modern tapes.
 
the more experienced here may correct me, I've never used that scotch tape but read they suffer from SSS. So make sure your heads aren't getting filthy from it. the atr tape maybe inappropriate as the deck needs to be calibrated for it, not sure if it easily doable. After replacing those suzuki bombs, try a maxell. I know they are getting pricey on fleabay tho. I have 3 of those decks, all I did was those caps, new belt, relubed and greased everything. They sound surprisingly good with old maxell. Do more forum searches, you'll find lots of info about that deck. good luck!
 
Thanks for the recommendation. The TEAC A-4010S definitely does not have the right bias/calibration for the AMR tape. The Scotch/3M tape works ok. I will check for Maxell tape. Found 1 UD 35-90 reel NOS, everything else is used on eBay.
 
WiDucPioneer said:
I recently purchased a TEAC A-4010S from a seller who has a lot of experience refurbishing old TEACs. Mechanically it's in pretty good shape, it's clean, had been lubricated and has serviceable belts. Electronically it's kind of a disaster
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It sounds like he sold you a deck that you're going to have to do most of the work on yourself, including getting it actually working at all. If I was the buyer, I'd hesitate to call what he's done "refurbishment" - perhaps definitions vary a bit?

When I'm looking for a deck to buy, refurbished to me, under the most lenient definition, suggests that it has been checked, worked on to some extent, and returned to some sort of working order. If not, I would expect the seller to make clear to the buyer that it is completely a "buy at your own risk" transaction. Any machine I buy under those conditions is, as far as I'm concerned, unchecked and not worked on.

Serviceable belts means the belts haven't been replaced - they may not need it, but no work has been done there. Lubrication could mean anything from a few squirts of contact cleaner here and there to carefully going over all switches and pots in the deck and making sure they are properly cleaned, and greasing/oiling parts that need it; for a TEAC, it should also mean removing the pinch roller arm from the bearing, cleaning the old grease off thoroughly, and relubricating. If it hasn't been done, you're probably going to have to do it yourself before long, the bearing will eventually start to seize up. You can test it by pulling the pinch roller towards the capstan. If it settles back into position slowly, it needs to be lubricated.

From your description, the seller has done a few fairly trivial "housekeeping" parts - and possibly not even some of those - that most users are capable of themselves or that a first time buyer can do following a little advice from forums like this. Any real problems with the deck have been passed along to the buyer; which is fine as long as that was how they represented it to you. "A lot of experience" sounds a bit off here, because people who do have a lot of experience would be likely to have checked more and repaired more and told you what you need to know before you bought it.
 
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Tonoje said:
It sounds like he sold you a deck that you're going to have to do most of the work on yourself, including getting it actually working at all. If I was the buyer, I'd hesitate to call what he's done "refurbishment" - perhaps definitions vary a bit?

When I'm looking for a deck to buy, refurbished to me, under the most lenient definition, suggests that it has been checked, worked on to some extent, and returned to some sort of working order. If not, I would expect the seller to make clear to the buyer that it is completely a "buy at your own risk" transaction. Any machine I buy under those conditions is, as far as I'm concerned, unchecked and not worked on.

Serviceable belts means the belts haven't been replaced - they may not need it, but no work has been done there. Lubrication could mean anything from a few squirts of contact cleaner here and there to carefully going over all switches and pots in the deck and making sure they are properly cleaned, and greasing/oiling parts that need it; for a TEAC, it should also mean removing the pinch roller arm from the bearing, cleaning the old grease off thoroughly, and relubricating. If it hasn't been done, you're probably going to have to do it yourself before long, the bearing will eventually start to seize up. You can test it by pulling the pinch roller towards the capstan. If it settles back into position slowly, it needs to be lubricated.

From your description, the seller has done a few fairly trivial "housekeeping" parts - and possibly not even some of those - that most users are capable of themselves or that a first time buyer can do following a little advice from forums like this. Any real problems with the deck have been passed along to the buyer; which is fine as long as that was how they represented it to you. "A lot of experience" sounds a bit off here, because people who do have a lot of experience would be likely to have checked more and repaired more and told you what you need to know before you bought it.
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Any reccomendatios for one where the capstan motor does not spin. Its free and has a new belt. Possibly starting caps? I see there is a 6 gang cap block in there. Checking voltages is difficult because it is hard wired
 
Just in follow-up to what Tonoje said, you may be at a decision point whether to proceed with efforts to fix the problems you are having with this deck or to initiate a significantly not as described (SNAD) case through eBay and return the deck to the seller. Based on how the seller described the deck in the listing and the issues you have discovered, you may have a valid case for returning the deck at the seller’s expense. If you proceed with making modifications to the deck, you will probably lose this option. You should consider carefully what you do next.
 
jimbo2k said:
Any reccomendatios for one where the capstan motor does not spin. Its free and has a new belt. Possibly starting caps?
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Certainly a possible reason if your deck is of similar age (which model were you talking about, by the way). You may well have trouble finding an exact match for those capacitors, in which case you'll have to get some with quite a different form factor. They'll also be smaller, and likely to be spec'd for a higher voltage - the capacitance must be the same as before though. You might be replacing the capacitor with two separate 2-lead capacitors, in which case, if it was originally a 3-leg capacitor, the ground leads will share a mounting hole in the PCB. If so, you'll need to improvise a bit on how to put them together and install them in the chassis. Shouldn't be too difficult, but not guaranteed to fix your issue either. However, it's a fairly harmless replacement procedure, and will save you having to do it later.


I should add that I'm going mostly from memory here, so do some more research or wait for someone else to weigh in before you go further.
 
It's an A1500 and it appears the capacitors are in a block. 5 or 6 in one rectangular block. One for each direction and speed I assume
 
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