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Help identifying toaster controller/timer chip

winelight

Dec 15, 2020
4
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Dec 15, 2020
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Below is the schematic for a control board for a toaster that uses a chip which is obviously functionally very similar to the PT8A2511 and the many other chips which have the same functionality and pinout as the PT8A2511 however, as you can see from the following schematic (which I have tried to lay out much the same as the one in the Pericom PT8A2511 datasheet), the pinout is different!

Of course the chips are unmarked. It seems the only possibility is that (for whatever reason I cannot imagine) this is a custom version? Does anyone have any other ideas please? I think I've tracked down every toaster chip I possibly can and they are either the same pinout as the PT8A2511 (or they are the simpler 4-pin version).

PSX_20201215_144921.jpg
 

PETERDECO

Dec 19, 2019
239
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Dec 19, 2019
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239
Welcome. It looks possible they replaced the chip with a microcontroller. The 8 pin PIC series that I use has pin 1 for B(+) and pin 8 for (-) ground.
 

winelight

Dec 15, 2020
4
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Dec 15, 2020
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That seems like a very logical explanation! Thank you. It does mean though that I've no nope of replacing them. But at least I know now.
 

PETERDECO

Dec 19, 2019
239
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Dec 19, 2019
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239
Are you sure that chip is the problem? If so, perhaps you can use the PT8A chip and alter the pinout with wires to the circuit board.
 

winelight

Dec 15, 2020
4
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Dec 15, 2020
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All the other semiconductors are fried (one transistor has physically blown apart, as have the electrolytics) so I cannot believe there is much left alive there. Certainly replacing with the PT8A is a possibility, but it would have to be on a daughterboard with a bunch of wires, the layout of the PCB is not really conducive to the amount of rerouting necessary. It would just be too much work really, I think.
 

winelight

Dec 15, 2020
4
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Dec 15, 2020
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Indeed. Sadly, this belongs to a customer (I volunteer in one of those community repair centres). But at least I can give my boss a proper explanation. They aren't easily put off by "Looks a bit complicated"!
 
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