Checking the Read Out Contact assembly

[Ron Rich]

Gentz,

The mechanisms that use the Solenoid Assembly Units (SAU), have floating contact blocks ("frogs"), that are held, FLOATING, in place by a "U" shaped spring pressure bracket-- OFTEN when these machines are "tilted" (during transport)  the frog will "jump" out of the bracket. IF you are lucky, you can "wiggle it" back in place without damage. HOWEVER, I have seen these brackets bent, beyond usefulness, and the "spring" bent/broken (See photo a  few posts below, of it sitting in the wrong position-- thanks, Jeff !).

Two types of "frog's" were used to "read out" selected torroids, on TMU equipped phono models (see my "Seeburg Mechanism Guide"). The first is a brown Bakelite version that either has 4 (tube type phono's) or 2 (SS phono's) sensors. These frogs have pins that are supposed to have a silver tip, on them--They get "gouged out", and must be FILED, down to a smooth surface--then, burnished. If there is no silver left  on them--it MUST BE, replaced !!  The tube types also have two pins in the center, that must be in good shape, too--the grounding bar in the center of the TMU must still be silver coated--or turned over ( mounting holes, may need re-drilling), or re-silvered. Cleaning the TMU, both, the gold plated, rivets, and grounding bar (if used), should be done with a non-residue safety solvent--then a VERY light covering with20 wt,oil.  The second type are "fingers" with a contact point on the end--same story--filed down/burnished/replaced. USE CAUTION here, as MANY times, if the mechanism is somehow run it the direction opposite of which "finger" is up, it will catch that finger, and bend it, rendering it useless forever !!  ( When "transporting" the phono--Be sure to use the two "thumb screws" as per the model I & O Manual !)  Also-- in all cases, use MINIMUM upward pressure when adjusting the frog, as excess pressure will only ware out the contact surface surface faster--won't be "more reliable" !!

If having "scans twice--intermittent or, no detent" problems, read all stickies here !! 

The small 32 gauge wires going to the sensors also tend to break--measure them with a meter as often they are broken INSIDE, the plastic coating.

Ron Rich

[nyjb]

Good to know, Ron. I'm working on a 222 with the 4 sensors. No problems with the selecting, though there is a little squeak from the frog that can't be a good thing. The sensors aren't perfectly smooth, just lightly gouged, but I'm afraid to file them too aggressively.

Just to be clear-- the VERY light coating of oil goes on the rivets as well as the grounding bar.

Finally, when it's properly set, should I expect a light chattering as the sensors scan the rivets?

Thanks, as always.

[Ron Rich]

Yes--and yes-- I also oil the pins--very sparingly where they enter the top of the contact block. Pins need to be filed/burnished so as to remove any/all gouges.
Contact block should be set to the lowest possible point --you must see "depressions" as the pins scan and hit the rivets, and the black limit bars must not touch the upper plate between rivets. Ron Rich

[armandh]

since we are in the area

if either the A or B side read out quits check the flexible wire connecting the spring loaded pin to the terminal strip.

they will break after many years of bumping along

FYI

NOTE the pins are offset to provide, mechanically, some timing advance

the first one [V-200] which traverses at a more majestic speed [slower] has a much narrower support block.

[Ron Rich]

Hi Armand,
Yep--true--also, one should be sure when replacing that broken wire, one uses only 30 gauge or smaller wire. Timing on the newer "fast speed" units is 4 ms from the trip signal, till the full detent position(if mechanism is properly oiled !). Ron Rich

[jetusenet]

I had this issue as my jukebox was transported without ANY precautions. Thanks to Ron, who guided me through, I found and repaired the Contact assembly and now are enjoying a beautiful M100C!

pics before the repair.......Note the "crazy angle" this frog holder is sitting at ---It MUST BE "squared off" to work correctly ! (edit:RR)

[joemlog]

I recently offered to get a HF100R-D working for a friend. First thing I've noticed is the contact assembly looks just like your picture! I have the service manual but it's unclear why that bottom portion looks twisted and how to straighten it out.
New here, thanks!

[Ron Rich]

Simple-- "force" the "bake-lite" back into the holder -- spring steel on the left can be "pushed in", to the left, with a small, flat, screwdriver, and frog should "pop" into place-- If the support arm is bent. the SAU will need to be removed and the "bent part" straightened out--or replaced !! Ron Rich

[joemlog]

Well straightened that out- now scans all left side, occasionally skipping a selection- but won’t stop to play any right side of record in scan mode unless I trip the mechanism manually
If this info is covered elsewhere please direct me to the thread.
Thanks so much!

[Ron Rich]

Hi Joe,
Whatz "scan mode" ? Service switch has three positions-- center is "off"-- stops whatever is happening at that point. Spring loaded left position-- start/run motor. Other position "Operate" (or run-normal) position. Didja read the "Hi Newbies" post in FAQ's ? Ron Rich

[joemlog]

According to the service manual, when the service switch is held to the left, it causes the mechanism to scan the carriage

[Ron Rich]

Hi Joe.,
Well, yep-- sorta-- It "turns on, 120 line voltage, and shuts off 25 VAC to the mech"-- If the mech is just sitting,it should be in, or close to the scan mode, it will scan, if the mech was in play, it will play to the end of the record and sit there and spin. It should NOT be able to detent when the switch is held against the spring. Ron Rich

[joemlog]

ok understood, thanks. I guess my next step is to pull the frog and check the contacts. Sorry I was confused lol. In play mode, while going through each selection, the carriage gets to the far right, reverses, but then never stops to play another selection

[Ron Rich]

Hi Joe,
See the service manual schematic-- can be a problem from the reversing switch to the frog sensor contact, on the B side-- Ron Rich

[joemlog]

yup have continuity from reversing switch to all frog contacts. saw earlier where sometimes a small wire breaks off the floating contact. After straightening out the frog unit now overscans past A1- when scanning from right to left won't stop to play a selection unless I manually trip the lever.
Should I wait for your book to arrive? lol thanks Ron