PC-3000 Forum

Hi, this Seagate ST3250310AS (7200.10) has a blown TVS, some resistors and
who knows what else because it doesn't work after replacing the obvious chips.

So, I tried to find donor controller. I have MANY with same board number:
"100468303 REV A" BUT, they all have a ROM chip on the bottom right of
the card. My blown one does NOT! And the other 2 8-pin chips that physically
have the same package, are not ROM chips, in my experience.

Out of desperation, I tried transplanting these 2 chips to a good card,
but it will not power up. If I add the ROM chip (ya, I know it's wrong)
to this Frankencard, it now powers up, but of course, stays BSY.

So, has anyone triumphed over this dilema, What to do?

(I will likely order the correct card (and still transplant the two non-ROMs??)
which has "100505691" on the white label. There are many other such
numbers on the ROM-equipped controllers.

Thanks,

Drew
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Hi there !

Either you try to acquire a PCB that is exactly the same as yours (without ROM chip) or you try to remove the ROM chip and the 2 resistors near it from a card that have the ROM chip on the place where your original pcb doesn't have any.

7200.10 pcbs on my experience are "compatible enough" for you to get in a easy way a replacement without even the need of ROM swap.

At any rate let's imagine that the pcb have masked ROM on the MCU and that code must be updated later on, they will add a ROM and populate some resistors near it so that the MCU reads ROM from the external chip instead of reading it from the contents on the masked ROM on the MCU.

If you remove the ROM chip and if original ROM content is still written inside the MCU, then the PCB should load to RAM the code on the masked ROM instead of the code on the external chip.

If you get a pcb with the same MCU number as yours you should be able to get it to be compatible.

Not sure if this will work but it's worth a try.

On the cases that I've done (on 7200.10) a simple PCB swap was enough (maybe I was lucky).