Started by Tw3ek, August 03, 2014, 09:08:29 AM
QuoteCommand * 1 Compatible models EffectRESET + [STOP] All models I will start with no memory check.RESET + [TAB] With HDD (connection) machine Display the OS selection menu.RESET + [ESC] With HDD (connection) machine Display the OS selection menu.RESET + [COPY] RAM drive loading machine Booted from the RAM drive. (Auto mode)RESET + [SHIFT] + [STOP] + [CTRL] PC-9801VX later I recorded in the FD a memory dump. * 2RESET + [CTRL] + [CAPS] + [Kana] + [GRPH] PC-9801RA, RX later CPU name, operating frequency, screen resolution display. * 3RESET + [CTRL] + [SHIFT] Only NOTE machine I want to initialize the memory SW of the body.RESET + [GRPH] + [SHIFT] PC-9801DA, DS, DX or later I want to initialize the memory SW of the body.RESET + [HELP] PC-9801DA, DS, DX or later Display the setup menu.RESET + [HELP] + [RETURN] CPU machine retrofit of some 4 * Display the setup menu.RESET + [GRPH] +  A MATE and later The 24kH view the display.RESET + [GRPH] +  A MATE and later The 31kH view the display.RESET + [HELP] + [ESC] +  PC-9821 and later Display the BIOS revision of the body.RESET + [HELP] + [ESC] +  PC-9821 or later The start sending memory refresh signal to the C bus.RESET + [HELP] + [ESC] +  PC-9821 or later The stop sending the memory refresh signal to the C bus.RESET + [HELP] + [ESC] +  PC-9821 or later View the BIOS update menu of the body.RESET + [HELP] + [ESC] +  PnP-compatible devices I want to initialize the PnP BIOS.* (PC-9821Xa / W, Xv / W, Vxxx, etc.) models no 1 RESET SW, Please replace the POWER SW.* Press the 2 [COPY], and then recorded in the FD a memory dump from being 1.2MB FORMAT forcibly.* There may not be displayed correctly when being replaced with a standard 3 CPU.* 4 PC-9821 Xa / W, in Xv / W, etc. VRM socket mounting machines, body retrofit to K6 series, such as the AMD CPU is intended for.
Quote from: SkyeWelse on September 11, 2014, 04:24:25 AMThat sucks to hear Caius. I did take a look at that guide and it does give instructions for soldering directly to the YM2608. I wonder if it's possible that the chip got damaged somehow? Have you by chance desoldered the DB9 and booted it in it's original state?If it is the chip there might be some places where a YM2608 chip could be still be ordered online, but likely in bulk. Maybe if you took pictures of what the mod looks like now that could be of more help. I'm not an electronics person myself, but there are a few of us that are that might be able to give feedback or tips to try. I still need to replace the capacitors in my Ce2 as well. I'll be honest in that I'm kinda scared to do it, but it must be done if I want to preserve it.Good luck with getting this working again!-Thomas
Quote from: caius on September 11, 2014, 05:47:22 AMHi,I fear the motherboard is fried.I soldered the wires directly to the YM2608 IC on the solderside and for that little I could play game it worked, I could correctly use my FM-TOWNS joypad connected to DB9.Then I got some scrambled white lines on screen so I immediately turned off the pc and removed the mod but now all I get is a beep.I'm a bit uncertain on what to do, if try to repair replacing the Overdrive CPU or accelerator card or put a new YM2608 (the best would be use a new motherboard but it's nearly impossible to get it) or get a new pc.Regarding replacing capacitors I higly recommend it since they were almost all bad, my PC-9821AP2/U8W uses strange SMT capacitors that look like tantalum but are electrolytic instead.Anyway thanks for your interest, I'll keep you informed about