Re: wurlitzer 1015 cd bubbler no sound

On 2016/03/04 10:01 a.m., John Robertson wrote:
> On 03/04/2016 8:42 AM, [email protected] wrote:
>> Is the CPU the 4CIC1/ST6225?
>> Are those chips available?
>>
> 
> I have no stock on them, but will check with Germany. I am not certain 
> that this is the problem though.
> 
> I suggest you call Rod, he knows a lot more about those amplifiers and 
> probably has that part in his stock.
> 
> John :-#)#
> PS, tell him I said "Hi!"
> 

Turns out the problem was the Zener diode 1ZD (3.3V) on terminal 3 of 
the 8.3VDC voltage regulator 1IC1 (7805). This probably shorted pulling 
the 8.3V down to 5VDC, too low for the circuits to work properly.

Replace that Zener Diode before doing anything else. A 1N4728A (1W 3.3V) 
should be OK, but I don't have the parts listing for the diode so that 
is a guess...won't hurt to use a higher wattage zener diode (1.5 to 3W) 
if the leads fit in the holes.

Thanks to Dietmar of Wurlitzer Germany (ex Deutsche Wurlitzer factory 
repair) for that solution!

John :-#)#
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