Otari MX 5050 BII -2
A very versatile and capable r2r deck. this one has some miles on it. I bought it off ebay circa 2008. It was advertised as being very much used but recently serviced and fully operational. I received the deck pretty much in the condition described. Rough around the edges, but everything worked. And I played some commercial tapes through it and thought it sounded pretty good, considering the output was piped through Otari circuitry and into the balanced input on my integrated amp.

Last year I decided to sell this deck because I had a couple of others in better condition. The sale over ebay went well..... until the buyer reported that he had received the unit in non functional condition. As in, nothing worked. Wow. When I shipped the unit everything worked. So, I had no choice but to refund the buyer and receive the deck back. When It came back to me I could see the problem. Shipping damage.

The deck had obviously been dropped by the shipper, I presumed. And it was likely dropped more than once. The 4 feet on the back side were crushed (smashed to pieces). Once I removed the back cover I found what you see in the above photo. The big tranny held in place by a single steel strap had broken its strap. Several plugs connect into the various features of the deck and these plugs held. So did the wires. However the transformer was free to swing about in pendulum fashion and crash into whatever might be in its path. The only evidence of obvious damage occurred here:

the largest of the PCB has a nasty crack near a fastener point.

Here's a close-up detail of the damage to it:

In the macro photo it can be seen that the crack in the board also wiped out one circuit. This, I presume, is the cause of deck malfunction.

It gives me an idea; 1) use adhesive to seal the crack in the pcb. 2) take a very fine guage of copper hook-up wire and solder it over the missing piece to bridge the gap and repair the break in that circuit.

I did this once before on an old car from the 1970's that had a similar break in the pcb that distributed current to the instrument display on it. That actually worked. Here it seems I have nothing left to lose. Either replace the board with another of same (but undamaged) or try the bridge repair.

For those who want to know, more installments on this project are to come.

-Steve

 FYI - Inmate51 08:18:55 10/13/15 (1)
 RE: thanks...! - user510 09:17:39 10/13/15 (0)
 RE: update.... - user510 19:24:01 10/17/15 (0)

...

Show full thread outline!

 FYI - Inmate51 08:18:55 10/13/15 (1)
 RE: thanks...! - user510 09:17:39 10/13/15 (0)
 RE: update.... - user510 19:24:01 10/17/15 (0)
 RE: A project machine.....with some history. - CAM3XL 13:02:52 10/04/15 (0)
 RE: first attempt.... - user510 11:57:50 10/03/15 (1)
 RE: first attempt....follow-up fix - user510 16:31:52 10/03/15 (0)
 RE: A project machine.....with some history. - Bill Way 17:46:14 10/02/15 (0)
 RE: A project machine.....with some history. - Listens2tubes 16:16:05 10/02/15 (3)
 RE: ...have I tweaked...? - user510 16:27:24 10/02/15 (2)
 RE: ...have I tweaked...? - John Elison 21:25:41 10/02/15 (1)
 RE: ...darn - user510 10:38:04 10/04/15 (0)

Two-part epoxy was used to repair the crack. After 20 hours drying time, I decided it had cured enough to stand up to the next step; creating a solder bridge over the broken circuit. It all seems to have worked.

With the circuit board re-attached, and all plugs re-inserted, it is time to test and see if anybody is at home.

Next step was to try it out. Wouldn't it be nice if the fix was as simple as this?! So I put the deck back on its little table, plugged the power cord in, plugged the balanced IC into the back of the Otari and the Integrated amp.

I pulled out the commercial tape, Blood Sweat & Tears, Child Is Father To The Man. Threaded and pushed play.

It seems to be functioning as before, except the tape counter doesn't light up. Otherwise, function and sound are there.

Additionally, it needs a pair of light bulbs on the left VU meter. That is as before.

But now I am reacquainted with the sound of the Otari output electronics. Not quite full sounding. Kinda' cheap. While I've got the covers off, I should likely do a bypass from playback head to an external tape pre-amp. But that will be the subject of another post on another day.

For now I need to source the problem with the tape counter malfunction. It had worked before.

-Steve

-Steve

• http://www.theanalogdept.com/manuals.htm