C128D repair IC # = C128?

[polishedball]

Hello trying to get a c128D up and going again.  It will boot to c64 mode,  the cart does work.   ON power up I get a boarder but no text just blank screen after a flash page of garbage.  From ray's repair docs I suspect.
U33       318018-02  C128 BASIC LO ROM
     No BASIC startup screen in 128 mode only. Computer goes into
"monitor" mode.

U34       318019-02  C128 BASIC HI ROM
     Blank screen with border at 128 mode startup. Lines or "garbage"
inside border.

   I have a donor c128 but the do the IC locations equal the same spot on a 128D board?  The chip #s are different between the two.   I did swap U34 as the board layout and trace that i tested was exact;  this gave me a "break error" and some ML code (?) following it when booted instead of the blank screen.  I think i am in the right area, suggestions or any info please.  Are there bin files and what type prom if they exist could be used to replace these. 

I have another working 128D, but dont want to chip swap it with this one as there is some hum in screen and audio of the broken one and I don't want to wreck anything know good.  I'll pick up caps and repair supply in the AM>

Thanks

John

[RobertB]

I have a donor c128 but the do the IC locations equal the same spot on a 128D board?  The chip #s are different between the two.

Why don't you send an e-mail to Ray Carlsen in order to find out exactly?

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[polishedball]

It appears that the chip for basic 7.0 in my 128D has both the high and low in one prom part number basic.318022-02.bin that equals 318018-02+318019-02 this would explain the break I got in the middle when only the low code was present from the swap and not the high.   

I have download a bin file for the basic.318022-02.bin  any idea what type prom size this burns onto?  the factory chip is a MOS and not a prom.  I am thinking it is a 27_256 but looking for opinions.

Thanks

[polishedball]

 :)Repaired    burning and swapping u34 fixed it up.

[maraud]

Great news!  Was it a 27256 or a 27512 that you needed?  I can't remember the size of the BASIC ROM.

[polishedball]

Great news!  Was it a 27256 or a 27512 that you needed?  I can't remember the size of the BASIC ROM.

27256 took care of it.