TAPCO S8 Studio Monitor - Transformer Blowing fuse - help needed

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aviel

Well-known member
Joined
Feb 6, 2018
Messages
96
Hey folks,
so suddenly my monitor started blowing up fuses, i opened it up, everything looked ok, i disconnected the transformer secondaries from the PCB and the connected back to the mains, and fuse still blows. so i suspect a shorting transformer.

now i am trying to figure out what transformer i need, according the schematic i see +-31V and +-15V after regulation. will a 22-0-22 traffo will do?

accroding to the specs each speaker is 20W on idle, and 100W when loud. fuse is 800mA for 230Vac.
now, what power rating? for 230V the fuse is 800mA, so i assume ,max current rating of 800mA -> so 230*0.8 =~200 VA, is this correct? i am curious because i saw a post forum when someone ended using 2X25 50VA.

also, could someone help me to understand why i have 5 wires on the primaries? not sure what the purpose of the 5th one..
 

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and a schematic (not sure if it is correct though..)
 

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The orginal transformer you can find here:
http://www.loudtechnologies.eu/shop/index.php?item=0012635&action=article&group_id=10000184&aid=2234&lang=en
BTW,  you are correct, a 2x22Vac, 50-80VA transformer would be ok. The primary fuse is always overrated because of a higher inrush current.
 
moamps said:
The orginal transformer you can find here:
http://www.loudtechnologies.eu/shop/index.php?item=0012635&action=article&group_id=10000184&aid=2234&lang=en
BTW,  you are correct, a 2x22Vac, 50-80VA transformer would be ok. The primary fuse is always overrated because of a higher inrush current.

Thanks! will 80VA be enough? the  monitor can use up to 100W..

can a shorting tranaformer happen because of another problem? i am afraid of getting a new one and blowing it also..
 
aviel said:
Thanks! will 80VA be enough? the  monitor can use up to 100W..

can a shorting tranaformer happen because of another problem? i am afraid of getting a new one and blowing it also..

Yes. The power supply components may be shorted.Look for a dead rectifier.
 
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