Portastudio 2488 (v1) - Error 4 - SDRAM

[Neo1607]

Got a portastudio a friend wants me to look at for them. Has a SDRam error 4, not much info googling it but the couple of posts I found suggest repair centres say to just scrap it and put in a new/refurb board.

I was wondering if anyone on here had successfully repaired this fault, I am assuming it's down to a failing ram chip, I am quite capable of replacing it, but with it being an intermittent fault. Is it a particular chip or cap that causes the issue or is it worth just replacing all the ram chips in one go?

 

[Adrian Pollock]

Hi, got the same error, did you ever get it fixed, if so can you give me some pointers. I have opened it up, ordered 3 x RAM Chips same as what is in the board, replaced the single one by the cpu but no difference. There are 2 more ram chips by a corner beside each other, both showing no output signal activity using and oscilloscope. Clock signal is present, chip select, RAS, CAS all getting correct vokrage, no output from either chip, the one by the cpu that I replaced shows loads of activity on the chip. Any help from anyone would be appreciated. Also if anyone has a schematic / service manual. This is for 2488 mk1. Thank you.