1961 Wurlitzer 2500 Restoration

This was a jukebox brought in by a customer. To me, it was the last good looking Wurlitzer before they decided to hide everything and go with the "box" look. This jukebox is the 2500...200 selections and mono/hi-fidelity sound. The jukebox was in solid shape upon arrival and it was apparent this jukebox led a sheltered life. The large amount of aluminum trim had minor scratches and the pot metal had some minor pitting. Originally the plan was to electronically and mechanically restore it but the customer decided on a full blown restoration. The machine was completely torn down to remove all the pieces that had to be plated, which was every trim piece. The parts were taken to Speed & Sport Chrome Plating in Houston.

Sorry, no "before" pictures! This restoration documentation starts with the jukebox stripped down to just the cabinet:

The cabinet sides were in solid shape with a few dings and scratches but it was not the original finish. The original finish was a light faux finish, similar to blonde finishes of the day. It had been removed by stripping and/or sanding. Although "OK", the current finish wouldn't look nice compared to the freshly plated chrome and something had to be done. I decided to hand sand the finish down to bare plywood. It had a mediocre wood grain typical of plywoods that were intended to be painted:

I went with a red mahogany stain that the plywood accepted well. It allowed some grain to show while largely "hiding" the plain grain.

I then applied 3 coats of semi-gloss lacquer:

Now the fun part...re-assembly. First up, the grille rods. The grille rods with their "hourglass" shaped pot metal pieces are one of the attractive design features but posed challenges. Each "hourglass" is actually two separate pieces. The rods were originally staked underneath and on top of an hourglass to hold everything in place. These stakes needed to be removed to disassemble for plating. How to re-assemble? I decided re-staking was out of the question so I drilled small holes where the stake marks were and then inserted roll pins.

With the grille rods assembled, assembly can begin. The cabinet was laid on its' back for ease of assembly. The light diffuser panel was cleaned and installed, followed by the installation of grille "anti-vibration" strips on the front of the cabinet.

Then the grille was installed, followed by the lower front panels (two pieces) and end caps, grille rods, side angled trim, and side bottom trim.

Now that the cabinet is upright, it is time to assemble the top half of the jukebox. The selection panel, instruction window panels, front glass, side panels, dome hinge panel and dome glass frame are installed.

The selection panel has been serviced (points cleaned/lubricated), new clear plastic caps installed on push buttons, new instruction windows installed, new light diffuser installed along with the coin return push button, coin chute and selection panel fluorescent light.

Before installing the lid glass the lid latch/stop needed to be repaired. Somehow the end of it had been broken off. I had no idea what it was supposed to look like (Wurlitzer manuals don't have that level of detail and I couldn't find anything on the internet showing what it was supposed to look like). So I improvised. The following pictures show the broken piece and the repaired piece.

The lid glass was installed. It is more easily installed with the entire frame assembly removed. The gray glass channel strips were first cleaned. Following glass installation, the dome fluorescent wiring was installed.

The remainder of the cabinet interior (title holders, etc) won't be installed until the mechanism is in place and working, which is the next step. As received, the mechanism was locked up in the "play" position. The carousel motor was removed so that the carousel could be placed in the "start" position. With the motor removed, brushes and commutator were inspected, both were in good shape.

Here, all the components have been installed and temporarily connected. The amp and distribution box have been rebuilt and it is ready to be powered up.

Jukeboxes are like old tv's...they never work right from the git go. Would this jukebox be the exception? After turning it on, the fluorescent lights came on...good. I hit the free play switch. The latch solenoid energized...good. And the "Select" light came on...good. Then a wisp of smoke from the front of the jukebox...bad. It appeared to be coming from an 85 ohm and 150 ohm resistor on the keyboard unit. Let the troubleshooting begin...

Troubleshooting:

The 85 ohm resistor is part of the latch solenoid circuit. The coil is initially powered via a set of contacts at the latch relay. When the coil energizes, these points open and the coil is powered solely through the 85 ohm resistor. For it to smoke means excessive current which in turn could be caused by a low resistor value (rare, resistors usually go high or open) or lower coil resistance due to shorted turns. I measured the resistance of the coil and it was around 50 ohms. I measured the resistance of the coil on a 2310 keyboard...50 ohms. So the coil was apparently not the culprit. I then examined the supply voltage. It is a negative dc voltage coming from a bridge rectifier across one of the power transformer windings. The schematic doesn't call out the exact voltage but it's probably in the neighborhood of 28-30 vdc. I was measuring 36 vdc. The original bridge rectifier was likely germanium diode based and had been replaced with something that was likely a silicon based diode rectifier. Silicon based diodes have a lower voltage drop. Combined with higher line voltages of today, the resulting voltage (20% higher) likely pushed the 85 ohm resistor to the point where it smoked. Same issue with the 150 ohm resistor which is in series with the "Select" bulb. This bulb is a #44...6.3 volts at .25 amps. The 150 ohm resistor is intended to drop the difference. For both, I bumped them up by 25% and increased the wattage to 5.

With the smoking resistors out of the way, I loaded a record in the A1/A2 slot and entered a credit. I selected A1 and the selection motor started as part of the indexing process. It stopped, the credit was canceled but the transfer motor did not start and this was because the associated pin had not lifted. I hit A1 again and this time the transfer motor started, the record carousel rotated until A1 was in position, then the record transfer began. The record arm lifted the record into place and the record began to play! The sound was excellent so at least the amp was working well. So everything is good to go, right? WRONG! I loaded a few more records. Pin lifting was still hit and miss so I still need to determine if this is mechanical or electrical. Then a new problem developed. As the carousel rotated while the unit was looking for the lifted pin it began to stop and go, stop and go, rotating a little each time. I looked at the back and saw the transfer switch flipping back and forth, throwing the transfer motor in and out of search mode and into and out of transfer mode. At this point in the cycle, the transfer motor is supposed to rotate the carousel until one of the indexing arms makes contact with a lifted pin, then the record transfer cycle begins. The transfer switch arm was in the correct position on its'cam but the cam itself was moving so it was obvious there was some kind of mechanical issue causing this. Wurlitzer's mechanism is a somewhat complicated affair with a number of components such as cams, lobes, one way springs, ratchets, and levers/arms that in conjunction with a number of switches forms the sequential operation of the jukebox.

A closer look at the transfer switch arm and control cam lobe indicated the problem. After a record has been returned, the transfer switch and motor are in transfer mode. The transfer switch control arm rides on a hub with the aforementioned lobe. The arm is moved by this lobe which in turn flips the transfer switch to "scan" mode. If no other selections are present, the transfer motor shuts off. The transfer arm is supposed to be totally on the lobe but in this case, it was on the upward slope of the lobe. It ended up being unstable, hence the "stop and go". I adjusted the adjusting screw on the transfer switch arm and that appeared to solve the problem. I also installed the missing stylus wiper brush cable (these always seem to be missing). The wiper assembly places a small amound of spring load on the transfer switch arm so this probably helped the "stop and go" problem too.

The last remaining problem (hopefully), the selection "misfires". At this point, I decided to make an inventory of all 200 selections to see if there was some commonality or other info that might aid in troubleshooting. I loaded records in the "A" and "B" sections, a total of 20 records and began the process. It didn't take long before another problem reared its' ugly head: no matter what number I pressed, a previous record would play. Some poking around the selector unit indicated number coil plungers were stuck in the down position. Could it be as easy as oiling the plungers? NO! The number plungers engage with tabs on the underside of the pivot wheel which in turn is driven by the selector motor. At the end of the selection process the appropriate number and letter coil energize, causing a pin to be lifted. Also at this time, the selector motor is supposed to briefly reverse direction to "free up" the number plunger and allow it to pop back up. This apparently was not happening. I manually closed the reverse switch and the selector motor operated as it should. There is an adjustment for this switch so it and the "play" switch below it likely need adjustment.

The play and reverse switch adjustment fixed the problem of the sticking number coil plungers. The start switch adjustment was close to where it needed to be but the reverse switch was quite a ways off. With two adjustments out of kilter already, it seems like someone with a "golden screwdriver" was in there before tweaking things.

The only remaining issue: the selection misfires. This is usually due to poor contact at the numbers/letters sliding switch units in the keyboard. It had originally passed continuity tests after cleaning contacts I could reach with solvent. I avoid completely disassembling unless I have to but the sypmtoms pointed to a keyboard problem. That means the keyboard had to come out (fairly easy), the switches disassembled, the sliders manually cleaned with a dremel wire brush and everything re-assembled. Only one bank of switches is easily accessible, the other two are blocked by the plate that contains the latch solenoid etc., requiring complete disassembly. Here is a picture of the disassembled keyboard with the numbers switches being worked on:

I installed the freshly refurbished keyboard and selections were still hit and miss! A few would work by repeating the selection but some just wouldn't select no matter how many times I tried. I could hear the selection motor operating, credits cancelling, etc but the mechanism motor would not start. I re-cleaned the points in the distribution panel (reverse relay, timing relay #2 and timing relay #3. Nope, still doing it. It was time to actually watch what was going on. A2 was a chronic misfire. I first hit "2", then while looking around at the back where I could see the electrical selector, I hit "A". The big ring that contains the pivot arms that strike lift pins rotated, stopped, and reversed like it should. The "A" coil fired as it should, the pivot arm struck the lift pin as it should but the lift pin didn't lift. Odd. I tried lifting it manually and it was stuck! Finally I got it freed and it was apparent some kind of crap got in there (it wasn't dried lube). I tried more lift pins, most of them were free at the back of the electric selector but at the front, many were stuck. Relatively inaccessible, I had to remove the mechanism and place it on the cart so I could deal with these sticky pins and there were a bunch of them. It looked like somebody had dumped a soda or a beer down the front of the machine and the sticky residue was causing the problem. I liberally lubed all the pins and worked them until all were moving freely. Then I placed the mechanism back in, hooked everything up, and voila, no more misfires! Case closed.

The Final Stretch:

With the jukebox now selecting properly it was time to finish it up...install the title holder and dome light panel, paint and install the cash box door and frame, install the coin return cup, and install the back components. Here is a picture with the title panel and dome light panel installed:

The cash box door was missing so I bought one on eBay. I painted both the frame and the door gloss black. I still need to buy a lock.