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PCW voltages on STK7308

Started by squelch41, 12:22, 17 April 24

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squelch41

Hi,
I managed to short out my PCW analogue board (Deeply annoyed with myself!)

I think I blew the STK7308. I'm using a pcw 9256. The data sheets are really unhelpful and I was trying to work out the voltages you'd expect on the stk's pins

With the STK in circuit, the board blows the overprotection diodesd d505 d511 and d512.
R501 gets very hot then burns out.

Removing the STK means none of this happens.

The transformer windings dont seem to be shorted (there is 'OL' reading if compare primary to secondary pins).

I just wanted to check before I solder in a new STK7308 to minimise the risk of killing it if Ive missed something!

Thanks


squelch41

Quote from: jevicac on 21:22, 17 April 24Consult this manual, I hope it helps you.

https://www.habisoft.com/pcwwiki/lib/exe/fetch.php?media=manuales:servicio:manual_servicio_tecnico_pcw_9256.pdf
yes, been using that but it doesn't show voltages at the primary or secondary windings of the transformer or the expected voltages an the STK chip

squelch41

In the end, I just converted to running on USBC PD.
12V feeding into the 12v line and a buck converter to derive 5v and feed that into the 5V line - all at the analogue board connector.

3D printed a new peice to cover where the mains cable used to come out.
Available on thingiverse for anyone who needs in future
(https://www.thingiverse.com/thing:6595466)

No 24V supply but I dont have a printer.
Could be generated from a boost converter but I'd imagine the wattage is quite high.

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