FS-A1FX video repair

By majors

Supporter (3)

Аватар пользователя majors

14-11-2018, 23:58

I picked up a FX that had a video issue. Upon first boot I was greeted to this screen:

Trying other games, I discovered issues with a few more:


It seems to only be on MSX2 games and not MSX1 titles. I looked over the mobo and did not see any glaring problems. Searching the site for similar issues, a few posts talked about video DRAM going bad. Here is what was installed before I replaced them.

So I went out an got some replacement DRAM, but I could not source 8ns and ended up with 10ns(D41464C). After installing(and adding sockets so if it did not fix it, I could keep trying or put back the old DRAM) it corrected the video issues I had. Just thought I share my experience with the group.

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By jepmsx

Rookie (31)

Аватар пользователя jepmsx

15-11-2018, 09:34

Thanks a lot for sharing your experience.
Could you post the picture of the final result? Thus the new sockets that you added would also be seen.
I think that the information would be more completed.
Thanks again!

By Alexey

Guardian (2457)

Аватар пользователя Alexey

15-11-2018, 11:53

Yep, thanks for sharing. Unfortunately we will see more and more failures of the RAM chips in our machines as the years go by...

By SkalTura

Master (192)

Аватар пользователя SkalTura

15-11-2018, 15:48

Did you also replace the elco capacitors, these cause all sorts of problems after a few years...

By luppie

Paladin (854)

Аватар пользователя luppie

15-11-2018, 20:13

Have you tried a memory tester, to check the vram?
Could also be a defective VDP

By majors

Supporter (3)

Аватар пользователя majors

16-11-2018, 15:58

jepmsx wrote:

Could you post the picture of the final result?

Here is a shot of the replacement DRAM installed with sockets.

SkalTura wrote:

Did you also replace the elco capacitors...

No, I did not see the need at this time but I'm well aware of cap failure with my other hobbies.

luppie wrote:

Have you tried a memory tester, to check the vram?
Could also be a defective VDP

I did run testram and it would crash while testing video RAM(further suggesting I had bad DRAM) but after installing the new modules, it passes the test with no errors. I'm glad b/c I feel it would be more of a challenge to source a replacement video chip.

By Nprod

Resident (37)

Аватар пользователя Nprod

16-11-2018, 18:45

Good call trying it out with MSX1 games, since those use only 16KB of VRAM you're less likely to run into a bad block of memory.