I will dig around but am curious if when you set the switches back to 90mhz setting does it boot and look ok ? DId you install a 133 and with switches still set at 90 does it look ok (and boots at 90mhz) ?

Horun wrote on 2023-10-22, 02:29:

I will dig around but am curious if when you set the switches back to 90mhz setting does it boot and look ok ? DId you install a 133 and with switches still set at 90 does it look ok (and boots at 90mhz) ?

The laptop starts without any issues when I change the switches back to 90mhz.
At least, the colors return to normal with the original switch settings.
The laptop is currently unable to boot due to the BR1225 CMOS battery being dead.
I won't be able to boot to an operating system until my replacement arrives.
(This is normal for the FMA7500AC, FMA7600 and Highscreen BlueNote I & II.)

The replacement battery has arrived today.
I am now able to confirm that this laptop is fully functional.
(At least with the Dip switches set to 90 MHz)

My plan is to set the Dip switches back to 133 MHz again. (With the internal Display removed)
I'll then use a benchmark program to verify if the CPU is actually running at 133 MHz.
The results will be posted here once I receive them.
Though, I'm uncertain if I'll do it this week.

Try settings for 100 and 120, and see if either of those send it screwy. If 100 does, it's the 66Mhz bus speed it doesn't like, maybe 66 had better RAM parts or wait states set. If that's fine and 120 does it, then it's something messed up with the multi setting. Possibly, you might have to try an external monitor to get into CMOS setup and relax timings or set wait states to get 66 working. If it should be that it works on 100 fine, then there might be a multiplier workaround by using a "wire trick" in the socket, or conductive pen on backside of pins.

BitWrangler wrote on 2023-10-24, 15:39:

Try settings for 100 and 120, and see if either of those send it screwy. If 100 does, it's the 66Mhz bus speed it doesn't like, maybe 66 had better RAM parts or wait states set. If that's fine and 120 does it, then it's something messed up with the multi setting. Possibly, you might have to try an external monitor to get into CMOS setup and relax timings or set wait states to get 66 working. If it should be that it works on 100 fine, then there might be a multiplier workaround by using a "wire trick" in the socket, or conductive pen on backside of pins.

No matter what frequency the CPU is set to, the laptop boots and displays without any issues when connected to an external monitor.
Despite my attempts to set the DIP switches, the internal LCD remains either unresponsive or displays incorrectly.
With 100 and 120 MHz, I only see vertical lines, and with 133 MHz, every text appears in red.
I already went to the CMOS setup, but there is no function that allows me to change the timings or set the wait states.

I performed the same actions on my second FMA7600 (the DSTN one) and surprisingly it behaves differently.
With 100 and 120 MHz, the internal LCD works just fine. However, with 133 MHz, it glows orange.
It's the same thing with the CMOS Setup though. It is not possible to modify the timings and set the wait states.

The multiplier workaround seems like a feasible solution.
If there are no other DIP switch settings available, I might give this a try.

Strange, I wonder if it's a power deficiency, pulling the PSU low enough with demand that the LCD is starved.

That's a good point. We shouldn't neglect the possibility of a power deficiency.
Though to me, it seems unlikely.
The vertical lines bear more resemblance to a defective GPU.
But this is most certainly not the case.
As I mentioned earlier, with an external monitor, it works perfectly.

I am willing to share some pictures if it is helpful.

Keep in mind that the vertical lines extend across the entire LCD Panel.

Wilius wrote on 2023-10-24, 18:40:

That's a good point. We shouldn't neglect the possibility of a power deficiency. Though to me, it seems unlikely. The vertical l […]
Show full quote

That's a good point. We shouldn't neglect the possibility of a power deficiency.
Though to me, it seems unlikely.
The vertical lines bear more resemblance to a defective GPU.
But this is most certainly not the case.
As I mentioned earlier, with an external monitor, it works perfectly.

I am willing to share some pictures if it is helpful.

Hi there, I'm a little late but I just found and have been testing an FMA7600 laptop. It was horrendously unstable and I couldn't figure out why until I ran CHKCPU.EXE and saw it was running at 120MHz, this thing is supposed to be 90!

I took some pictures before I started testing it and noticed that the dip switches for 7 & 8 were in halfway positions so who knows what they were set to.
I found this great newsgroup post from 22 years ago that had some ideas for dip switch settings - https://groups.google.com/g/comp.sys.laptops/ … /m/OC1HvSrPEvUJ

That lead me to trying out different settings and here's what I've learned so far:
SW1-4, 5 & 6 are for the C&T graphics chip LCD driving mode settings. I was able to get lines and red text on my TFT by messing with these. These should not be changed unless you're swapping out the screen.

x = on
- = off position

4-5-6
- - - displays on tft but shifted halfway down (different resolution than 640x480?)
- - x normal vga tft display
- x - no display on tft
- x x normal vga tft display
x - - tft displays but is shifted to the left (different resolution than 640x480?)
x - x no display on tft
x x - no display on tft
x x x tft displays but white text is now red
Changing these changes the display type between mono / colour dstn and TFT, possibly with different manufacturer timings. The video bios contains tables for different display types and these 3 binary switches toggle through those 8 settings.

SW1-7 seems to switch between 50MHz and 66MHz, sort of. I don't really understand it too well.
SW1-8 appears to relate to cache settings, enabling it makes the computer far slower and looking at this - page 31 of the Clevo 7200 service manual suggests it switches between pipeline burst and cyrix mode. This is a slightly later Pentium laptop from Clevo. That description matches with my tests which showed L1=60MB & L2=40MB when enabled, disabled gives L1=160MB & L2 = 52MB

Knowing that SW1-4,5,6 are display related, SW1-7 is speed related and SW1-8 should not really be changed, I started testing all the combinations. This CPU doesn't overclock well and I won't change the processor out, it's not overheating since the heatsink thermal pad was replaced to no positive improvement. I just want it stable.

Here's the initial testing, to show how much difference turning SW1-8 on and off makes:

Now the tidy version which shows what results with my P90 SX968:

I'm not sure whether the dip switches would all behave the same on your one with a different CPU. Be aware also that there may be two versions of the FMA7600, one that had the P90 and a later one which may have had a P100 but I'm not sure what the differences are between the two. You could check whether yours has the same chips as the ones in these two pictures:

Now the dip switch settings are known and the CPU is back at its initial 90MHz setting, the laptop is stable enough to install an OS 😀 If only the fans were a bit quieter...

Hi! I apologize for not responding to you sooner. I haven't had the time until now.

You deserve a medal for the amount of effort, you've put into your research. Thank you a lot for your help, I appreciate it!
Thanks to you, we now have a comprehensive guide on how to easily upgrade the CPU of the FMA7600.
That's awesome!

Admittedly, I'm a bit disappointed that this thing can't handle CPUs faster than 120 MHz. I had high hopes of pushing it a little further.
It appears that I was overly optimistic about the FMA7600.
After testing both my FMA7600 laptops (DSTN and TFT versions), it seems that they both run stable at 120 MHz.
I'm satisfied with that.

I guess my next mission will be to find a RAM module that is larger than 8 MB.
Also, I'll attempt to replace the old hard drive with a CF card, provided that the BIOS supports CF cards to begin with.

In any case, you have answered all of my questions.
Having said that, we can consider this thread to be resolved.

Thank you a lot!

Wilius wrote on 2024-07-12, 22:03:

Hi! I apologize for not responding to you sooner. I haven't had the time until now. […]
Show full quote

Hi! I apologize for not responding to you sooner. I haven't had the time until now.

You deserve a medal for the amount of effort, you've put into your research. Thank you a lot for your help, I appreciate it!
Thanks to you, we now have a comprehensive guide on how to easily upgrade the CPU of the FMA7600.
That's awesome!

Admittedly, I'm a bit disappointed that this thing can't handle CPUs faster than 120 MHz. I had high hopes of pushing it a little further.
It appears that I was overly optimistic about the FMA7600.
After testing both my FMA7600 laptops (DSTN and TFT versions), it seems that they both run stable at 120 MHz.
I'm satisfied with that.

I guess my next mission will be to find a RAM module that is larger than 8 MB.
Also, I'll attempt to replace the old hard drive with a CF card, provided that the BIOS supports CF cards to begin with.

In any case, you have answered all of my questions.
Having said that, we can consider this thread to be resolved.

Thank you a lot!

Glad I could help, the other day I was trying to figure out what all the DIP switches do on an Acer 350PC laptop which has no service manual. I learned a fair amount in the process, specifically that this stuff isn't unique to any laptop and the operating system can lie or guess what the CPU speed is rather than knowing any accurate figure for the Pentium era CPUs.
The DIP switches are toggling multiplier and frequency settings, which will differ between CPUs and there are differences between socket 7 (mmx capable or not) and 5.
This page has great exhaustive info that's great for a quick reference: https://www.pchardwarelinks.com/cpuspeed.htm

Checking out the pins with the CPU removed and my previous board shots, I determined that there's no switch or connection for the BF1 pin so only the "BF" pin can be toggled and it's very much a Socket 5 with no split voltage capability. Checking with the oscilloscope I determined which sw1-1 and sw1-3 combinations give which frequency settings - so my test results weren't too far off.
Also it looks like SW1-2 should just be off, I've found no positive to setting that to On.

I'd love to know what the button / hotkey to toggle the Turbo is, I've only been able to change that by modifying that setting in the BIOS.

For reference for others, perhaps if anyone has display issues in future. Could you add in what the SW1-4/5/6 dip switch settings currently are on your DSTN and TFT displays?