"tripping", when selection is made--

[mick1950]

Not a drug related question,all I take are those prescribed for oldies.Just started going through this,been stood many years.Have serviced the receiver,it now has healthily flashing OA2s,battery test works as it should.Next I want to fix why the mech trips on or off every time I make a selection.If I make a selection whilst scanning it trips immediately,make another selection whilst playing the trip solenoid pulls in again.My thoughts are my next task is to go through the ES and scan switch?Please be gentle with me Ron :-).
Mick

[Ron Rich]

Hi Mick,
First change the 12AX7 and 2050. Re check ( I am assuming you changed all lytic and paper caps) the 2 watt 56K resistor in the TSU. Then change the 5.6m resistor in the PA.

If still doing this--check ground (earth) to mechanism--and to TMU. If still doing this, clean WI contacts in pricing unit (which one is in this phono ?) Still doing it--Remove/Wash TES in hot soapy dishwasher detergent--then rinse, in hot water, then re-wash in (sudsy, if you can get it) ammonia--rinse in hot water---allow to dry before using--be sure to remove the solenoid and any meter(s) prior to washing--re-install when dry--

Refer to the above sticky--"random selections"---

Ron Rich

[robnyc]

If this is still happening after proper TSR rebuild or develops later it is caused by faulty ground connections at the tormat male Pin 33 and/or the shell of the RCA plug on the pulse amp.

In order to avoid nusiance service calls at my locations I often just added a short jumper from that connection on the Jones plug to a close-by screw on the chassis front. I do the same for the pulse amp plug shell. Use a spade lug at the screw end.

As Ron points out, both 12AX7 (pulse amp tube) and occasionally the 2050 will cause this problem. The 12AX7 does this when the cathode develops hot spots and the grid loses proper control and the 2050 can suffer from this as well.

RobNYC

[Ron Rich]

Hi All,

ES WASHING INSTRUCTIONS:

What I do, is remove the (T)ES,from the cabinet.  Remove the latch bar solenoid(s-if used), and any total selections meter. Then wash in HOT dishwasher (liquid) soap, followed by a HOT water rinse-- don't use too hot a water on the later units with the black "plastic" guides-- follow this rinse with another wash in hot (soapy,if available) ammonia--followed by a rinse in hot water-- DRY TOTALLY prior to re-installing the items removed-- followed by a drop, of  20 wt. oil on all moving parts-plus a slight coating of a graphite based grease, on sliding parts.

I know that some people like to dis-assemble the TES, and use a "Dremel tool" on the slides--I do not do that, if at all possible to avoid-- slides and all contacts were silver plated-- the tool removes the plating !

Rob's correct--as I mentioned "ground(earth)", above--it also happens due to "contact cleaner" "sprayed" onto the TES--that's why the "washing instructions" above. The TES MUST BE clean/dry and free of anything that can "conduct"--thus preventing "flash-overs". Ron Rich

EDIT--I combined these posts into a "sticky" as this is the same for any tube type Tormat equipped, phono ! Later solid state units are essentially the same circuit, too. "MicroLog" models, and, "100 77/8" models,  differ in Write-in functions, but Read-out is the same, up to the SMC models.

[mick1950]

Many thanks for replies,plenty of areas to check when I get back to it next week.Just to mention I did replace that resistor and the cap in the pulse amp and reflowed the wires on the rca that plugs into it.Before I did the caps in the receiver the OA2s werent lit,they now have a nice glow,two of the fine wires were off the contact block too.Will report back later.
Mick

[vipertblck]

Nov 16, 2018 13:48:58 GMT robnyc said:

If this is still happening after proper TSR rebuild or develops later it is caused by faulty ground connections at the tormat male Pin 33 and/or the shell of the RCA plug on the pulse amp.

In order to avoid nusiance service calls at my locations I often just added a short jumper from that connection on the Jones plug to a close-by screw on the chassis front. I do the same for the pulse amp plug shell. Use a spade lug at the screw end.

As Ron points out, both 12AX7 (pulse amp tube) and occasionally the 2050 will cause this problem. The 12AX7 does this when the cathode develops hot spots and the grid loses proper control and the 2050 can suffer from this as well.

RobNYCJust did this few days ago on a 201; grounded out pin 33.  fixed my issue; although a bit different than here.  mine was accepting the letter and number on the ES, but not releasing them.  acting like a wallbox was hooked up taking selections, so it "disabled" the jukes ES from accepting selections.  by grounding pin 33 as you said, it allowed it to work properly and release the keys, and take the selection.  the V contact in the stepper was open and needs to be closed, by grounding pin 33, it did the same result as if V was closed;  sure enough when I looked in the stepper unit, V was open.  a quick turn of that wheel assembly inside there allowed the contact to close, operate accordingly with the jumper wire removed.  just wanted to share as it was similar to what's going on in this post.

[robnyc]

:"RobNYCJust did this few days ago on a 201; grounded out pin 33. fixed my issue; although a bit different than here. mine was accepting the letter and number on the ES, but not releasing them. acting like a wallbox was hooked up taking selections, so it "disabled" the jukes ES from accepting selections. by grounding pin 33 as you said, it allowed it to work properly and release the keys, and take the selection. the V contact in the stepper was open and needs to be closed, by grounding pin 33, it did the same result as if V was closed; sure enough when I looked in the stepper unit, V was open. a quick turn of that wheel assembly inside there allowed the contact to close, operate accordingly with the jumper wire removed. just wanted to share as it was similar to what's going on in this post."

There isn't any connection between the Jones pin and the stepper holdout so, I don't know what was going on. There are connection on Timing RY #2 that transfer the W-i pulse from KBD to stepper (points R-Q). Another set N opens the pulse. I've always eliminated both sets, if they get slightly mistimed either set can cause enough noise to cause the mech to trip at W-I from the stepper.

RobNYC

[mick1950]

I will go through all these tips,suggestions in the morning and report back.Did notice last week an occasional reluctance of the keys to release.Up to now apart from servicing the receiver and PA and cleaning the memory pips,resoldering rca and wires on contact block nothing else has been touched.Know for sure the amp needs work as its pretty silent bar the odd crackle when I move the pots.
Mick

[robnyc]

Mick, do yourself and the machine a big favor, take the --5U4 out--. An unrebuilt amp of that age will be leaking DC into areas where it must not be. The result will be eventual destruction of the power transformer, and the output tubes and transformer. The fact that turning the volume control produces noise is one sure indication of DC leaking into it.

You can remove the amp altogether and still work on the rest of the machine.

[mick1950]

Thanks Rob,will do!
Mick

[Ron Rich]

Rob,
Never thought about "DC leak" when a VC was noisy-- Just sprayed VC cleaner* into them--cleared it up 99% of the time--1%, I just changed the pot ??
* suggest "Deoxit-5"
Ron Rich

[robnyc]

Nov 19, 2018 14:03:39 GMT Ron Rich said:

Rob,
Never thought about "DC leak" when a VC was noisy-- Just sprayed VC cleaner* into them--cleared it up 99% of the time--1%, I just changed the pot ??
* suggest "Deoxit-5"
Ron Rich

Ron, the way it goes:

Noise only during signal: Dirty pot..

Noise with no signal going through, then you are hearing DC crackling on the carbon of the pot.

One repair shop I occasionally worked at was a owned by a typical crew-cut crook. Tube radios and phonos would come in with noisy pots, he'd just spray them, button it up and charge the customer. A month or so later the same complaints... Finally, at the age of 11 I took it upon myself to find out why this happened so often. It took maybe two minutes with a VTVM on a Zenith Am-Fm table radio (this was 1967).  Mr Crewcut admitted that he knew the capacitors were cheap and leaky but that "it don't pay to bother on these five buck jobs -just get 'em out the door".  He did have a nice American flag in the shop window though..

There were two other repair shops nearby and their owners were a lot more honest and i worked there. BTW: this was the busiest time of the year for repairing phonos and stereo equipment including those huge consoles. It seemed that these people never listened to music except during the holidays. I worked full days  after school and weekends, it was fun and educational..plus, I got to keep stuff the customers didn't want to get repaired.

Rob

[Ron Rich]

Thanks --never dawned that he would be turning pots, with no signal--- Ron Rich

[Ron Rich]

Guyz--One person did not understand that a "proper rebuild" INCLUDES a check of all resistors, and replacing any that are out of spec. Also includes replacing the germanium diode (when used) with a silicone type (1N4004, or better works). Ron Rich

[Ron Rich]

Guyz,
One thing that was forgotten here-- a "dirty" ground connection between the RCA plug and RCA socket- clean the socket ring with a crocus cloth-- tighten the plug rings--slightly-- Ron Rich