Teac 22-4: Relays or something else?

[Scot Solida]

My son and I had my 22-4 deck apart last weekend and gave it a thorough once-over. We cleaned contacts, etc. When we put it back together, it worked better than before... but still not entirely. Track 3 still doesn't play in Sync mode (it did two weeks ago, but this seems an intermittent issue). Much of what I read suggests that this is a relay issue. There is a dedicated relay board with four Omron relays on it. I am assuming that there is one for each track, but I do not have a service manual, so I'm just guessing.

In any event, I was wondering if any of you folks knew the part number for the relay? Anyone have a line on where to find the replacements? And am I on the right track? Can the relays be cleaned if I can't find replacements?

I seem to remember that this deck used to also exhibit minor speed instabilities, but this problem has not cropped up lately. Hopefully it won't... my tech hasn't returned my call, so I fear I may be on my own here.

[Skywavebe]

Hello Scot Solida,
I have not seen one of those in a long time but assuming they used the same small DIP relays as in the 30 series, they can be a problem and from the 30 series design, they ground the head lead that needs to be grounded. The cleaning of DIP relays is not possible if they are the ones I have been thinking about. Pretty much what you need to do to figure a replacement is to go to mouser Electronics online, and put that relay number in and if nothing comes up then you might have to do some research as to what is a compatible item. I did either buy my relays from Mouser or DigiKey but they are available. The way to test the relay contact is to put the unit in sync mode and then on the relay you think is defective solder a wire across the contacts that are suppose to be closed and then you will know if function returns. You could also take the relay out and test it on the bench with an ohmmeter. I usually replace the relay with a machine pin IC socket so that will allow you to change it out when it is needed.

[Skywavebe]

Hi Scot,
I did a little looking and this is the relay I bought- see if it matches the one you need physically. I tried to get a Service Manual from Hi Fi Engine but they don't have it there. The way to get a real one even though it costs is from stereomanuals.com .
The manuals from Stout and associates have always been top notch.

Here is the link to the relay that worked. They also have the SPST relay as well.
http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&site=us&keywords=306-1039-ND&x=8&y=14

http://www.stereomanuals.com/index.htm

[Scot Solida]

Thanks Sam... Those don't look anything like the relays in mine... mine are the clear type. I'll take a picture this weekend. They are all on a dedicated board with some bias controls. This board is accessible from the bottom and sits next to the channel boards.

I have a Mouser account, so maybe I'll get lucky with a replacement part. I have been planning a big order form them this weekend, so if they have 'em, it'll be good timing.

[Scot Solida]

Didn't get a chance to take pictures... (camera battery dead when we were working on it). The relays are the clear type. We popped 'em open and cleaned them, but to no avail, I'm afraid. Sync on track 3 still isn't working. Ah well. Wanna get on with making music... I'll just continue to record track 3 last. My 15-year old son has two of my Tascam 38s on the table now, trying to salvage parts from one and put 'em in the other. He's doing a danged good job of it, too.

[Audiomayvin]

Hi Scot and Sam!
An easy initial test is to swap boards. Each of the 4 channels has it's own plug-in board.
All the best,
Leon(The Audiomayvin, Montreal(514)739-5403)
P.S. You do understand that I will shoot you if it's a dirty head!

[Scot Solida]

Thanks for the advice, Audiomayvin. No dirty heads here. You know, I think we forgot to swap cards out on this one (go figure, we have three decks on the bench at the moment and two in the tech's shop). We'll try that and see if it changes anything. I got the service manual yesterday, so I can finally see what's what (more or less). From a quick perusal of the manual, I think we've been focusing on the wrong relays.

We're getting closer though! The 22-4 is almost there, and we've got one of my 38s just about ready to go (couple minor things left: meter lamp in one channel, sticky needle on another meter).

[tapetech]

If you swap the channel cards and the track 3 sync problem stays on track 3, then you have a defect solder joint on the mother board. Specifically the through-pins, which have a history of going bad. You can ID them by their hollow core. Resolder all of them.

[Scot Solida]

Excellent advice. Thank you! I will check it out!

[Scot Solida]

...Specifically the through-pins, which have a history of going bad. You can ID them by their hollow core. Resolder all of them.

This was exactly the issue. Good call, sir!