dreamshell bios flasher cannot detect bios chip

[chth96]

I finished to dual bios mod.
But when I boot off with DS boot loader in original bios and switch to MX29LV160TMC-90 new bios then select bios flasher from dreamshell menu and select detect option...But It display unknown Model, size 0kb, voltage 5v, access read only.
It cannot write any bios file and display error code2.
I don't know what caused it fail to detect new bios..

https://ibb.co/c8tbDXy
https://ibb.co/vwpW3Mn
https://ibb.co/X3XMk3B
https://ibb.co/g4Fp3KM

[megavolt85]

need debug information, open console and make screenshot

[chth96]

Thank you very much for reply.
I tried to melting more solder in order to strongly join original bios and new bios(MX29LV160TMC-90).
But...While soldering..I mistakely broke pin 12 of MX29LV160TMC-90
https://ibb.co/x6GdkmK

I think that there is no hope to revive pin 12 of MX29LV160TMC-90,so I desoldered new bios(MX29LV160TMC-90)..And to make it worse... dreamcast is unable to boot off anymore...
I fiddle with soldering iron and solderwick for 5 hours in order to correctly solder original bios, I narrowly fix the problem of unable to boot off by desoldering remnant solder which join adjacent pin in the back side (gap of pin and origianl bios is too narrow, It was extremely very very hard to desoldering remnant solder from back side)
hah...dual Bios mod is very difficult for soldering novice like me...

[megavolt85]

you can cut through the microcircuit case and solder a thin wire to pin 12

[chth96]

I know this tweak of cutting microcircuit case.I saw it from dragoncity's blog.
https://www.obsolete-tears.com/sauver-un...r-119.html
But it require grinder which I don't have..