Newbie Wurlitzer X202 problems

Hi all and thanks for the add to the Forum. I've been searching around the topics for a few days, you sure do know a lot about Jukeboxes.

I need some help with getting a 1982 Wurlitzer X202 Estrella back to life. I'm an experienced electronic engineer living in Ireland and I've fixed up pinball machines and guitar amps in the past but this is my first jukebox. I've got a full manual with schematics etc., which is great, but I'm struggling to know where to start as the machine seems to be in a really strange state.

I read some posts of similar vintage Wurlitzer and did the following tests:
On switch on the amp seems to come to life as there is noise out of the speakers, the illumination works and the turntable motor operates but nothing else.
I get 888 on the display and none of the keys do anything when I press them either in operate or test mode.
The gripper arm is past the turntable pushed down by quite a strong spring onto the floor of the mechanism.
Pressing the LT reset on the SCC changes the display to a small u in the upper part of the first display.
The K and Z leds on the SCC are always on.
When I push the credit button the M led flashes and the display changes. It looks like it's counting up but the segments of the display are all wrong.
All the fuses are OK.
Checked the 30v and 2x12v AC supplies to the SCC and they seem OK.
there is no back up battery cell in it so I moved the jumper to memory off position.
I've checked C22 and it looks like it is working although the voltage across it rose to 14.9V and the schematic said it was working off a 10V supply.
I've dismantled, cleaned and tested the keyboard switches.
Also dismantled and inspected the display board, resoldered a few joints but nothing obvious.
Starting to wonder if there's bit missing in the mechanism, not easy to get a good picture online to compare. I'll add a few pictures below.

Sorry for the long first post but I really want to try to fix this machine.

Thanks in advance

Philip

Lichtschranken Lampe Prüfen .

[www.jukebox-world.de]

Ist die defekt dann kann die SCC nicht erkennen wo der Sync Punkt am Korb ist und auch nicht Zählen .

Display Stecker Richtig herum eingesteckt ? Das könnte die merkwürdigen Zeichen im Display hervorrufen .

Hi, thanks for the help.

Tonight I did dismantle and test the light switches on the record holder. The light was not working, the lamp was OK but it had a dirty connection, the photo transistors are ok. When I cleaned the lamp holder it started to work. The record holder still will not rotate but when I rotated it manually the K and Z LEDs on the SCC are now working.

I have attached a photo below of the display connector, is it the right way around?

I think if the lamp was so oxidised that it did not work I probably need to clean all the contacts on the SCC connectors and plug in IC's.

I still think however the machine is not in a normal state. I got the gripper arm adjusted into a more normal playing position but the pin that would release the record for playing seems to be on the wrong side of the lever that would control it, see the photo below. Is there a way to manually cycle the mechanism to get it into a known position.

Thanks again for your help.

Philip



1 mal bearbeitet. Zuletzt am 18.05.21 00:22.

Display Stecker sitzt Richtig .

So einfach lässt sich der Mechanismus nicht Überlisten . Grundposition ist immer Greifarm steht über dem Plattenkorb und die untere Klaue ist geöffnet . Der Mikroschalter unter dem Greifarm schaltet den TT Motor ein und sorgt gleichzeitig dafür das der Korbmotor nicht anläuft .

I still think however the machine is not in a normal state. I got the gripper arm adjusted into a more normal playing position but the pin that would release the record for playing seems to be on the wrong side of the lever that would control it, see the photo below. Is there a way to manually cycle the mechanism to get it into a known position.

Das ist so weil keine Platte eingespannt war im Greifarm als der sich Richtung Plattenteller neigte . Dadurch ist der Stift an der Klaue nicht hinter dem Arm gelandet sondern davor . Wenn du Reject am Verstärker drückst dann muss der Getriebemotor wieder anlaufen und der Greifer in seine normale Position zurück kehren .

Ansonsten mal den Service Schalter Kontrollieren . Der muss Durchgang haben und die sind gerne mal defekt vor allem wenn du schon schreibst das die Box Oxydations Probleme an der Lampenfassung von der Lichtschranke hatte . Die Schalter Oxydieren von innen . Gegenüber Chassis Masse sollten am Schalter 30VDC zu Messen sein .

Thanks for all the help. Tonight I cleaned and tested the test/operate switch, its working. I don't get 30v on the test switch I get about 5V with about a 0.5V drop when I switch it. I have a red wire with 30v from the bottom coin switch pin on the SCC going to the switch assembly but its wired into the simulator switch. The other two wires (green and violet) go from the switch assembly to the green connector on the SCC, which seems right. I can't find the switch assembly in the wiring manual wiring diagram, so it's hard to know if this is right.

There is good news I cleaned and tested some switches on the record mechanism. Now when I close K8 the turntable motor stops. Then if I hold K8 closed and press the lever for M3, the record holder rotates and the K and Z lights work on the SCC. I was very happy to see it turn for the first time. But the reset switch still doesn't reset the gripper. For a while the display did change when I pressed reset, all the segments flashed and the error light lit up, this is not however repeatable.

The display is also still doing weird things. I'm going to try and get some logic probes and a scope onto the SCC tomorrow and see if I can see what's happening in the 7 segment drivers.

Thanks again, another update tomorrow.



1 mal bearbeitet. Zuletzt am 19.05.21 00:13.

Ich denke du hattest die falsche Service Switch . Ich meine die auf dem Chassis vorne zwischen Plattenkorb und Plattenteller . Dieser Kippschalter mit der Aufschrift Service ON/OFF unterbricht die 30VDC ( blue wire in , green wire out ) zum Greifer Motor für Service Zwecke . Diese 30VDC müssen die ganze Zeit dort anliegen . Ansonsten hängt da nur noch ein 18 Ohm Widerstand in der Leitung die zum Motor geht . Somit muss auf dem grünen Kabel am Motor immer annähernd 30VDC anliegen . Geschaltet wird nur Masse über Relais MM auf der SCC . Der Motor hält sich aber selber je nach Getriebestellung über K6 und K1 , das ist die Kupfer Belegte Nockenscheibe im Getriebe .

Yes I was on the wrong service switch, I was on the test/operate switch beside the SCC. I'll test the switch on the chassis first thing tonight.

Thanks again, this is really interesting.

Sorry not a lot of time tonight just managed to test the service switch and load/operate switch on the chassis:
The Service on/off switch is operating OK but it has -30v on it not +30v, relative to 0V on the SCC.
The load operate switch beside it is faulty it is a short circuit in both positions and has 0v on it.

I'll try and do some more later.

It looks like the faulty shorted load/operate switch is not the problem, it carries the supply for the SCC and it being closed all the time is ok. I spent al lot of time studying the manual tonight and noted that this line actually carries 30VAC, and when I switched the meter to AC that was correct.

While I wait for some parts to arrive to test the SCC and display I'm going to focus on the gripper motor. I'm going to look at it more closely tomorrow but it looks to me that you could rig a test for this through pin 1 of the socket mounted on the chassis, jumping it to 0V at pin 6 on that socket.

Also I tried to listen for the credit relay to switch when I pressed the credit button and didn't hear anything, are the relays loud enough to hear them operate.

the manual talks about a K2 cancel button on the amplifier, but I can't find it.


Thanks for your help and ideas

K2 befindet sich direkt neben dem Netzschalter auf dem Verstärker .

Die Relais hört man auf jeden Fall schalten .

Der 9 polige Sockel auf dem Chassis ist für Zusatzgeräte wie Stepper oder Zählwerk . Ob das so funktioniert wie du das geschrieben hast kann ich nicht sagen da ich Momentan mit einem Schaltplan einer OMT arbeite . Da gibt es diesen Sockel bzw. Steckplatz nicht mehr . Du kannst aber eine Brücke am unteren linken blauen Stecker ( X4 ) der SCC zwischen Pin 1 ( grün ) Masse und Pin 2 ( blau ) zum Getriebemotor machen . Dann muss der Greifermotor anlaufen .

Hi the test with the socket contacts is the same as you suggested with the SCC blue connector. it was successful and the gripper motor worked and cycled the gripper arm and the turntable motor, I'm very happy with that. I also tested the A/B solenoid M6 and it worked.

So a lot of key parts on the chassis are working, which is great. There's a couple of things left on the chassis that I still need to work on:
The tone arm does not seem right the cartridge is working (sound out of the speakers if I touch the stylus) but when the gripper cycles the tone arm moves a bit but not anywhere near the right position to start a record. There is a bit of lateral movement but no vertical. Then when the machine is in a play state if I move the tone arm over the record to the end position nothing happens. I did find a loose spring in the bottom of the cabinet tonight I wonder if its off the tone arm, I'll add a picture below.

The other problem is I can't get the solenoid M3 that pulls the latch for the basket motor to work. I see that it gets its power through K71. When I looked at the cam lever that drives K7 it seems loose (easy to move). Through the gripper cycle it never closed K7. Can you please confirm that K7 should have the cam lever pushing against it with the gripper in the rest position. I'm going to try to test K7 next but it's hard to get at with all the moving parts.

Generally I'm quite happy with how things are going, more and more of electro mechanical bits are testing OK and it looks like it's the SCC where the real problem is. These are interesting machines to work on. All jobs have drama, tonight I slipped off a contact during a test and shorted something, small flash and then an anxious wait while I worked out what had happened. I'd shorted out the -27v to GND, blew the fuse, easy fix, drama over, lesson learnt, be more careful next time.

Thanks again for all the help.

K7 ist ein Bekanntes Problem und muss Schalten damit die SCC Richtig arbeitet . Durch K7 fliest eine Spannung sozusagen Rückwärts in die SCC und macht dort eine Rückmeldung .

[www.jukebox-world.de]

Dein Tonarm Problem könnte das selbe sein wie bei diesem Beitrag .

[forum.jukebox-world.de]

Thanks for the link, I checked and that spring is in place. There are some other springs listed on that site that I will also check.

While I was checking under the tone arm I found this small screw in the bottom of the cabinet. I've had a real close look at it and it has not been sheared this was its original size. Where is this from?

Thanks again.

Könnte eine Schraube seitlich vom Münzprüfer sein .

Worked on K7 tonight desoldered it, removed and tested it, it was faulty on K7/2, dirty contact, gave it a good clean and it works now. Refitted K7 and now I can get the M3 solenoid to pull in and move the record rack, good news.

I tried to get the gripper arm to lift a record. It will lift it off the turntable and put it back in the record rack but it can't lift one out of the record rack, doesn't grip it. I'm assuming this is an adjustment issue and I'm not going to spend time on it until I get the rest working.

So now there are two main problem left the SCC and the tone arm.

I looked more closely at the action of the tone arm. It actually make all the right moves but they are way out of position and too small, it never gets over the gripper arm. It is really hard to see what's happening with the tone arm, I think to find out what's happening I will need to take out the chassis.

Before I do that I'm really now going to start work on the SCC properly. I can see that the relays are not operating, the display is all wrong and the input keys have no effect, it's clearly got problems. As a first step I pulled the PIA chip out of the socket and inspected it. Definitely signs of oxidisation on the pins and probably in the socket, I cleaned the pins and tried to clean the socket but it made no difference. Tomorrow I'm going to remove the SCC so I can get a closer look at it.

It's getting very interesting.

Tonight I did a lot of work on the SCC but without any progress.....very disappointing.
I checked all the power supplies are good.
I took the SCC out removed, cleaned and reseated all the IC's in sockets, the sockets were dirty but it made no difference.
I think the power on reset is good but I will change C22 to be sure. I will also try and capture the reset on a logic analyser tomorrow.
The computer will not take any input from the keyboard.
If I simulate the transistors switching the relays operate, I can't get the computer to switch them on.
I read another post and it looks like I have the older model of SCC without the optocoupler IC16, so I checked T22 and it is switching and supplying 0V to IC22 pin 7 when the record is playing and 4.4V when the gripper is at rest.
I've ordered a new CPU and PIA.
Are there any other know common failures of the SCC that I could test.

Thanks

Nicht wirklich , die SCC ist auch für mich immer wieder ein Teil mit Überraschungen .

Hello Philip, to rule out a POR timing violation (slow starting oscillator/ degraded POR cap) force the reset pin manually into reset state after power up. Check the CPU power supply with a scope for excessive voltage drops(bad filter caps). If you see activity at the ports, you can check those for correct hi/low levels, rise- and falltimes. I guess that's about all you can do to check the CPU part unless someone knows a secret testmode for the board.
Rgds Jürgen

Thanks, that's a good idea, I'll force the reset. I've seen some scope shots in the manual I'll try and see if I can test them also.

So I tested the supplies: 14V with 2V ripple, 38v with 1v ripple, 5V with 2mV ripple. Not the worst but I've ordered new smoothing capacitors.

The forced reset of the CPU did make the display numbers change but it did not fix the problem, after a few second it went back into the same broken state, displaying 889 and not reacting to the keyboard.

I then tried to check some of the tests which have timing pictures in the manual, with an oscilloscope.
I tried to check the CPU clock (PIN 39) and didn't get a good signal. I thought this was the problem but with no clock nothing would work and the SCC is reacting to some things, such as the LT switch. Also I checked the CPU Enable signal (PIN37) and it was exactly the same as in the manual, as this is generated by the CPU it leads me to believe the clock is OK. I've ordered another crystal anyway.

I did the other tests and the only one to show anything interesting was when I monitored PINS 14 on IC 21 and 22 which I think are to do with reading the keyboard. I did not get a signal anything like what is in the manual, see the picture below. This probably is why the keyboard is not working. I tested all the keyboard and other inputs into IC 21 and 22 and they all work perfectly. I spent al lot of time cycling the SCC when I was doing these tests and could see a regular pattern on start up. PIN14 is driven from the PIA, so that might be faulty.

It seems that most of the analogue I/O functions are working, it's starting to look like it is a problem in the digital circuits.

The problem that will really stop me is if the program in the PROM has been corrupted. Can you still get PROM chips for these machines or does anyone have an image to burn a new chip.

Any thoughts welcome.

Welche Program Version hast du denn verbaut ? Frühe SCC habe ein Prom ( ohne Fenster ) und spätere ein e-Prom ( mit Fenster ) . Prom könnte ein Problem werden . E-Prom ehr nich wobei hier wirklich die Version wichtig ist um die Checksumme zu Vergleichen ansonsten ist bei 2.4 , 2.5 , 2.8, 2.8.1 alles egal am besten ohnehin auf die letze Version Updaten .

Thanks for the info. It is a EPROM chip M5L2732K with a sticker on it, which I think says MBOX 2.5. Is it possible to get the checksum to test it.

Great progress, the new stylus arrived and I fitted it. I was then able to cycle the gripper arm and get it to play a record, except the tone arm had to be manually placed on the record. It was great to hear the Jukebox play music.

Planning some more testing of the SCC later. I want to see if the multiplex signals for the keyboard and the displays from the PIA look right. Also the capacitors arrived today so I'll change C22 on the power on reset circuit.



1 mal bearbeitet. Zuletzt am 27.05.21 20:51.

So I checked the 3x 7 segment display common cathode driver transistors T6 T7 T8 were switching in turn with a scope and it seemed to be OK, not sure about the levels but the timing was ok.

I got a cheap 8 channel logic analyser off ebay and it worked well with some free software. I used it first to look at Pins 2,3,4 and 5 of the PIA. Pins 2,3 and 4 are the lines that send the switching information to IC 21 and 22 (to read the keyboard switches) and pin 5 is the disable signal for these chips. For it to work pin 5 has to go low but as you see in the trace below it looks like its always high, its Channel 3.

So I need to find out why it's not switching, unfortunately pin 5 does a lot of other things to so I'll have to try and work out if one of the IC's is pulling it high or if the PIA is not sending the right signal out.

I took out the PIA chip and bent back PIN 5 so I could look at it on the scope, isolated from the rest of the circuit. It just stayed at 5V no matter what I tried to get the box to do. this is not right so maybe the PIA chip is faulty, I've ordered a spare and it should be here in a few days. In the meantime I'm going to have a look at the CPU/PIA interface. It will be really hard to work out what's going on but with the logic analyser I might have a chance to make sense of it.



1 mal bearbeitet. Zuletzt am 28.05.21 19:59.

Good news, I think the SCC is fixed. I took it out today and lifted it off the backing plate. There was some oxidation on the underside that I cleaned off. Then I replaced the reset capacitor C22 and the PIA and CPU chips. when I put it back in the machine the keyboard and display started to work correctly for the first time.

When I tested it there are still some problems but I don't think they are the SCC:
Three of the four separate display lamps are faulty. I used the good lamp to check the other positions and the SCC is driving them, I will order new lamps.
The machine would not pick a selection and it wouldn't move the basket in test mode. This again was a problem with the K7 lever. It will not stay in position, when I adjusted it again the machine selected the record I had entered in the keyboard, I was very happy. I think I need a new K7 lever.

This leaves the problem with the tone arm position and no cut off at the end of a record. To look at this I will have to remove the chassis. When I do this I will take some pictures and see if we can work out what's wrong.

When the record was playing I noticed that the quality of the sound was not good and the levels were jumping about. I traced it down to the volume potentiometer and tone switches in the amplifier. I have removed the amplifier and cleaned all the connections and potentiometers. I will put it back together tomorrow and test it again. If the problem continues I will just hard wire the switches in a fixed position.

Making real progress again, thanks for all the help.

Tonight I put he amplifier back in and after cleaning the switches and contacts, it sounded better.

So then I started working on the tone arm. I can't work out if it just needs set up or if there is a part broken or missing, maybe the spring I found. I did test the contacts under the tone arm and they were not good, they worked a lot better after I cleaned them.

I've taken a couple of photos of the tone arm mechanism could you please let me know if you think any parts are missing. I can take more photos if it's not clear.

Thanks again

Hi all I have had a close inspection of the tone arm and I think I have found the problem. The small worm screw that I have highlighted in the picture below was lose. I think it's item 21 in the tonearm diagram in the manual an M3x4mm screw. There is a hole for another worm screw at 90 degrees but it empty.

Does anyone know how to setup this worm screw. what is the position of the tonearm when it is tightened. I've tried to do it by trial and error but with no success.

Thanks again

Just to close out this thread, the final problem was the grub screw. It was loose and after a bit of adjustment and tightening I got the tone arm working ok. I then had to adjust the cut off switch for the end of record K3. With all that in place the Jukebox worked properly for the first time, playing and replacing selections from the keyboard.

It was great to finally get everything working.

That's not the end however, now the real hard work starts, the juke box has been standing unused for a very long time and is very dirty. I will have to dismantle it bit by bit and give it a deep clean, polish all the metal and repaint some parts. I may cover that in another thread. I'm happy to do this work now, as I know the Jukebox will work when I put it back together.

Thank you all for all your support and help during this fix, especially Swen.

Now I need to pick 50 records.