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electronicsguy
electronicsguy, Engineer
Category: Recorders and Players
Satisfied Customers: 600
Experience:  Worked on these instruments for over 15 years.
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I have a TEAC 4010s that was working fine when suddenly the

Customer Question

Hi,
I have a TEAC 4010s that was working fine when suddenly the forward, reverse, and brake function stopped working. It will fast forward and reverse though. I have the manual and see the general location of the relay boards as well as having the back off to see where everything is. I've had this machine since 1970 and hate to lose it now. Any Ideas would be appreciated. Thanks. Paul
Submitted: 11 months ago.
Category: Recorders and Players
Expert:  electronicsguy replied 11 months ago.

Hi Paul welcome to just answer.

The tape system has a number of relays. On the play back, the pinch roller is pushed on the large metal sprindle. Can you check if the spindle is spinning. If yes, then we can focus on relay identification. I am thinking that we might have to change some belts and/or relays.

Would you like to have a phone discussion on this system.?

Customer: replied 11 months ago.
The capstan spins forward and reverse, but none of the following functions work: the pinch roller does not move to the "play" position against the capstan, the brakes don't release on "play"(though they DO work on fast forward and reverse), forward and reverse playback. I have to assume there's a common denominator to these several functions as they would all have to function together in order to play the tape.
Expert:  electronicsguy replied 11 months ago.

Ok, is you system open that you can manually prose the head cover by pushing it by hand? If yes, press play and manually push the head cover and let me know if this works.

Customer: replied 11 months ago.
I can manually move the heads up to the "play" position. The pinch roller moves to "play" position as well, but the solenoid that moves them is not responding when I press the "forward" or "reverse" buttons. Nor do the brake pads release either.
Expert:  electronicsguy replied 11 months ago.

Ok, so you might have to identify the solenoid and try to get replacement..

Expert:  electronicsguy replied 11 months ago.

Any lucky with identification ?

Customer: replied 11 months ago.
No, that's what I was hoping to get some help with. I have the schematic, but I'm not that good at following it as there are many relays each with anywhere from two to six contacts. But even if I could figure out what relay it is, it's still possible that it could be a burned out component associated with it. Then I'd have to try to find a 46 year old relay. It's looking like I may have to just scrap the machine and maybe find another on E Bay or something. Hate to do it, but it's looking like more grief than I'm able to handle.
Expert:  electronicsguy replied 11 months ago.
Would it be possible to scan the curcit diagram and attach it here for me to review and send you suggestions?
On the wiring diagram, you will have a way to trace wires that goes from each relay. What you can do is to measure resistance on the relay using an ohmmeter and if the coil is open, we will know that it is damaged.
If you feel that this might be a tough process, I would probably look on eBay to see is someone is selling parts for these. I have worked on different models and they share some common parts.
Customer: replied 10 months ago.
Hi,
Attached are both the transport and amp schematics for the recorder. I'm familiar with testing the relays, but they are fairly inaccessible(on three separate boards) without pulling a bunch of other stuff first which is why I'd like to have a better idea which relay it may be. But again, my basic problem is that I am not real good at following schematics that have multiple relays that have multiple contacts. I guess I could just pull the boards out on the assumption that the problem IS a relay. I would have to pull at least one of them out anyways. I'd certainly would prefer to not pull more stuff out than necessary as this thing is 46 years old. As you know, you never know what you can mess up when you start working on old equipment. Anyways, here's the schematics. Good luck! Paul
Expert:  electronicsguy replied 10 months ago.

I have looked at both schematics. There are two things you need to know. The solenoid has two sets of connection:- the coil part where voltage is applied and the mechanical part that actually move the system where it is supposed to go.

Expert:  electronicsguy replied 10 months ago.

Now if you look at different coil, each has its own resistance. You can use ohmmeter to measure resistance across the coil when it is disconnected from the circuit. Measure all the coils if you can to see if there is one that is out of normal.

Customer: replied 10 months ago.
Part of the snag is that the relays are A) on separate boards mounted upside down in hard to get at areas and B) they're soldered on. I'm hoping to get a better idea which board might be the culprit before I start yanking things. There has to be a common denominator that makes the: take up reel, the brakes, and the capstan roller arm fire. The mechanism that allows the tape to contact the heads operates from the same solenoid as the pinch roller. Now it's not a done deal that it's a relay, just seems likely. But yeah, maybe we need to do a conversation to get things moving so I know if I need to send this thing somewhere or scrap it, or what.
Expert:  electronicsguy replied 10 months ago.

Do you have electrical measuring instruments?

Customer: replied 10 months ago.
Three of them!
Expert:  electronicsguy replied 10 months ago.

Ok great while power is off, measure resistance a cross one of the coil. It might give you and indication of whether there is continuity or not. Try the same test on the other tests and compare the results.

Customer: replied 10 months ago.
Well a couple of things. I was hoping you would be able to tell me what the common denominator is for this problem so I don't have to unsolder all the relays to test them, which can be dangerous on a machine 46 years old. But now more important is that I decided to put the thing back together to see if by any chance it would take off. Well, I plugged it in and now it's popping it's fuse every time. A brand new problem. I'd like to have this one operational, but this problem is much harder to diagnose. So I'm throwing in the towel and may look for another used machine. Maybe not. I have probably 25+ tapes, but I'm not convinced it's worth the money buying another used one. I don't know right now. But we can hold up diagnose the existing problem in light of this new development.
Paul
Expert:  electronicsguy replied 10 months ago.

I think the fuse problem is probably related to what is going on with play back. I am afraid that you might have pushed some cables and short some wires.

My suggestion will be to get this looked at by a repair person as my online help is limited.

Where are you located?

Customer: replied 10 months ago.
Hi,
I was given the names of several shops here in Michigan by TEAC. So that's not the question. It's become more one of whether or not this thing is really worth putting money into. It's 46 years old, I don't use it that much, and most of what I use it for I can find on YouTube. It would certainly be an end of an era for me but still is it worth it? When I break it down I see that the components are all hard wired in tough to get at areas, I can't quite make out the schematic(which is what I was hoping you could help me with), and TEAC doesn't know if they have the relays (if that's actually the problem). So if you add them all up, it makes it questionable about the value of pursuing this further. Right now I'm sitting back and trying to decide, but I'm leaning toward just scrapping the thing.
Expert:  electronicsguy replied 10 months ago.

Well,

Thanks for using just answer. Unfortunately, we could not get your system up and running. We are limited to online help and if you would like to get further assistance, I would defiantly evaluate repair vs replacement cost.

Thanks very much!

Customer: replied 10 months ago.
I guess I'm not clear why I was charged for a consult that I had not yet rated. It was my understanding that I had to be satisfied with the service first before I was charged and now I see it posted on my VISA. I can't say as I was any further ahead for the consult. What I asked for several times was to be led to the relay or area where I might find the problem. After sending in the schematics for analysis, I was told to test the relays without being told which one(s). I repeated that they are all hard wired in and have 6 to 8 leads on them and that I can't just pull them all. I needed to know more specifically what the common denominator is for the problem. I didn't get that. I have to guess that it wasn't possible to read/interpret the schematic. Were I told that right up front, we could have ended the conversation right then. But to be told to test the relays wasn't answering my questions. I know how to test them, I just wanted to know which one if in fact that was the problem. So help me out, why is the charge posted already? Did I miss some fine print somewhere? On one hand I appreciate the effort but on the other hand I never got the information I was looking for from the beginning.
Expert:  electronicsguy replied 10 months ago.

Paul,

The charge on your card is for security deposit and not a final cost. You will be refunded once you are done. I do not expect you ratell any of this as I could not fix your system online. I will go ahead and ask for you to get your refund. Unfortunately what I provided to you was not good enough. I will opt out and have other experts try to assist you.

Customer: replied 10 months ago.
The charge was listed as "pending" for several days, but then became an actual charge, making us liable for payment. So I would appreciate the refund. At this point I'm going to just scrap the whole project as it's already become more work than I expected just trying to find out where the problem is. So there's no need for a referral. But I appreciate the effort.
Thanks, Paul