TCC1 from LPC480

[rwood]

Hi,

I am trying to get the Seeburg working again.

I made the mistake of turning it on without a dim bulb limiter and fireworks did ensue - inside the 2050s it appeared although I shut the unit down within seconds. It turned out that the 6X4 had been swapped for one of the 0A2s. No idea why….. but nevertheless.

The 2050s test bad with cathode shorts, so I’ve got some new ones coming. While I have the tormat control out I figure I should recap it and wonder if there is anything else I should do.

I see 5 Lytics (one looks to have been replaced) and 7 paper caps (also with one recent one in there). There’s also a FWB selenium rectifier that I’m wondering if I should tend to anything else in there. The 5W 3.3K fusible resistor tests good.

Can I upload a pic?

[jukeboxmarty]

I would make sure the transformer tests good before going any farther.

[rwood]

Good idea; thanks, Marty.

[rwood]

The PT passed a dim bulb test so with no tubes installed I measured all 7 secondaries and all check out okay. They are all very close to the schematic, even without tubes.

What should I do next?

[jukeboxmarty]

At this point I would go ahead and re-cap.

Before powering up, make sure the 6X4 is not shorted.

I usually don't replace selenium rectifiers unless they are bad (or weak).

[rwood]

The 6X4 tested good on one plate but bad on the other so out it goes. I’ve never seen a rectifier wired this way. Is this done to develop negative voltage? I noticed that the Lytics all go Positive to ground.

Should I clean the relay contacts while I wait for parts?

Thanks for the informed replies - it’s most helpful!

[jukeboxmarty]

Yes, the power supply produces negative voltage.

Cleaning the contacts is not a bad idea, as long as it's done right.

Check out this thread:

jukeboxaddicts.proboards.com/thread/5/contacts-care-cleaning-replacement

[rwood]

I put the new electrolytics in and new 2050s, 6X4 and 0A2s. I have not yet changed out the paper caps or the 12AX7s.

It passed the DBT so I tried it out in the juke and there were no fireworks this time but also nothing else happening. The tube filaments warmed up. No scanning action. Are there voltages I should check? I saw some pin voltages on the amp schematic but not on the TCC1.
Thanks as always.

[jukeboxmarty]

Are your 0A2's glowing?

I had to go back to the TSR6 schematic to find one with voltages. Although the two controls centers are vastly different, they share many common basic circuits.

[rwood]

Yes, they are glowing a white light as opposed to amber.

I took pictures but don’t know how to post them here.

I don’t remember which position the service switch should be in, but I tried all positions.

Its possible I don’t have the molex connectors in the right places (since I’ve already proven I can put a tube in the wrong place.)

[jukeboxmarty]

If the 0A2's are glowing you are probably getting appropriate voltage at the regulators.

The scan control circuit is pretty basic. Do you get any solenoids clicking when you toggle the service switch into scan position?

If not check your plugs and possibly the 15 amp fuse across the 25VAC.

[rwood]

Some progress! Reseating the connectors and nudging the carriage and it’s now scanning. It goes down and back several times and rests near the left end. I did that sequence three or four times.

It hasn’t picked up a record yet.

[rwood]

What are my next steps to get it to pick up a record?

Does something need to be reset or cleared out?

Thanks. I feel like I am close. If I can get it to play I will reward it by getting some speakers and maybe even replacing the particle board baffles that got flood swelled. They are usable but it would bother me.

[jukenorman]

You could maybe try the battery test or "battery trick" which is how I think the sticky above is named - check it out and follow the guidance. It's difficult to say how actually close you are but the battey test would certainly give an indication. Nothing needs to be reset.

Norman.

[rwood]

Thanks for that. I did the battery trick on both RCA plugs and the carriage picked up the right record right away. But then it slowed down to zero speed.

Does the turntable drive need to be cleaned and lubed? Or maybe something with the auto/speed?

This forum is great.