Wurlitzer 2150 Blowing 8/10 fuse on stepper unit

[toberlindacher]

I recently moved my 2150 Wurlitzer that was working fine before and now it is blowing the 8/10 selector fuse when making selections.  It works a couple of times and then blows.  I can't find any pattern to when the fuse blows.  It typically goes after the first selection but it doesn't matter what number or letter is selected.  I have it currently set to freeplay for testing but had on coin operated before with the same result.  Any ideas where to look?  Number and letter solenoids?  I have a manual and cleaned the stepper and keyboard switches with no difference.  Thanks.  

[Ron Rich]

Are you making selections using a "wallbox" ? If not, the "stepper" switches are not in the circuit. I do not have a manual handy, but going from my great, but not too long memory-- isn't there a "rod" on those that determines which set of pins will be pulled ? If so, I have seen that dirty--thus causing a long delay while selecting--which intermittently bows that fuse-- DO NOT use a larger fuse !!! Ron Rich

[Ron Rich]

Upon further reflections-- How, didja "clean" contacts ? I also seem to recall two timing relays were used in this process-- are they clean-- no "dirt" collected between the pole piece and the armature either ! Ron Rich

[toberlindacher]

Thanks Ron. I have a wallbox but was not using that to make selections. I'll ignore looking at the stepper then.  I clean contacts using a piece of businesss card soaked with a bit of deoxit and rub it between the switch contacts. This far, I have only cleaned switches but have not looked at the timing relays. I will have a look and report back.

[Ron Rich]

Also, look at the FAQ's section here-- cleaning contacts post-- IMHO, Deoxit, ain't much good on them ! Ron Rich

[mexnielsen]

Apr 13, 2022 13:53:35 GMT Ron Rich said:

Also, look at the FAQ's section here-- cleaning contacts post-- IMHO, Deoxit, ain't much good on them ! Ron Rich

I have repaired several old amplifiers and radios (Bang and Olufsen from 1960 to 1980), I use Deoxit on all open switches and potentiometers, where I cant get new ones. The most important with Deoxit is that it has to come off again. I apply Deoxit and leave it on for 10 to 15 min I then clean it off with isopropylic alcohol, left on the Deoxit will dry and leave a thin layer that in time will become like an oxidation layer. I have radios and amplifiers where I used Deoxit still playing without problems after 10-15 years. I never use it on plugs and jacks only on open contact and potentiometers

[toberlindacher]

I found the issue in the keyboard switches. I have to push the letter buttons in a bit more to get it to complete the circuit. I'll need to clean and adjust. Thanks for the help.