I did get past this screen just now but then when I reset it, I get a black screen - no beeps etc. Please help

limboy777 wrote:

Hi chaps. […]
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Hi chaps.

Please can you help. Ive got an Amstrad 486 SLC 33. This is a special motherboard for me as I can use it to upgrade my 386 sx Amstrad Mega PC so giving up is not an option.

It was all working fine. I changed the Dallas battery which kept BIOS settings all fine. Then I tried installing Windows 95 using floppies (used on track disk manager first). Partway through the installation, it had some kind of CAB Error which I couldnt do anything about so I aborted the installation. The PC has been running for a good few hours to let the Dallas battery charge.

After I did this , I think it said something about restoring it to back what it was (cant remember). When it did this, it went to a black screen with a white line that seemed to be showing some sort of progress. It was stuck about midway through so I switched the power off. Since then it wont get past the initial screen which states the following:

GL-GD540x/542x VGA BIOS Version 1.10
Copyright blah blah blah

(see photo)

It doesnt even get to the point of listing the processor, ram etc. I cant even reset using CTRL ALT DEL!

Ive tried unplugging HDD, FLOPPY, Soundcards etc. Checked everything was seated. I just dont have a clue why it suddenly has frozen on this screen.

If I take the Dallas battery out, it makes a beeping sound, ive tried the dead dallas battery which used to at least get to the specs list before saying CMOS error.

I would be grateful for any help on what may have caused this.

Try to disconnect the Dallas battery and any power to the PSU.
Wait a couple of hours and then try again.
This is to clear the CMOS.
Most motherboards also has a jumper to clear the CMOS.
Just make sure that your replacement battery does match the specifications of the original one.

jesolo wrote:

Try to disconnect the Dallas battery and any power to the PSU. Wait a couple of hours and then try again. This is to clear the C […]
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Try to disconnect the Dallas battery and any power to the PSU.
Wait a couple of hours and then try again.
This is to clear the CMOS.
Most motherboards also has a jumper to clear the CMOS.
Just make sure that your replacement battery does match the specifications of the original one.

Thanks for your reply. I will disconnect now and try in the morning.

I think the bios of the motherboard is worn out.. Maybe some bit errors in cmos.. Now checksum isnt correct, motherboard doesnt boot anymore..

Try to see if you can replace the older cmos with a new cmos chip with the right value and maybe you need a new rom image. Dont think that the motherboard is bad..
Otherwise the computer give you a blank screen if something.. Now it only hangs in boot.

Robin4 wrote:

I think the bios of the motherboard is worn out.. Maybe some bit errors in cmos.. Now checksum isnt correct, motherboard doesnt boot anymore..

Try to see if you can replace the older cmos with a new cmos chip with the right value and maybe you need a new rom image. Dont think that the motherboard is bad..
Otherwise the computer give you a blank screen if something.. Now it only hangs in boot.

Thanks for replying.

I tried taking the Dallas battery out and the power cable and leaving it overnight but still a black screen 😢

The other chips I can see that can be taken out are one that states American Megatrends and another thats says AMI (this one looks like a programmable rom). Is one of these a CMOS chips (sorry if thats a dumb question).

are the chips getting warm when you leave the mobo turned on by lets say 5 minutes?

jcarvalho wrote:

are the chips getting warm when you leave the mobo turned on by lets say 5 minutes?

Which chips should I check?

I touched the processor last night to check and it was fine.

Can anyone tell me which on is the jumper to reset CMOS?

(Are you JCarvalho from Amibay? - I sold you a commodore 1084s monitor a long time ago if you are!)

Hi! Yes I am!!! 😀
The 1084s is in good health and pumping 😁, great monitor!!
I am sorry that you have all these problems with the Mobo 🙁
I was asking if you feel the chips like cache and CPU warm (it means that power is on MB)
Thanks!
Jorge

jcarvalho wrote:

Hi! Yes I am!!! :) The 1084s is in good health and pumping :D, great monitor!! I am sorry that you have all these problems with […]
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Hi! Yes I am!!! 😀
The 1084s is in good health and pumping 😁, great monitor!!
I am sorry that you have all these problems with the Mobo 🙁
I was asking if you feel the chips like cache and CPU warm (it means that power is on MB)
Thanks!
Jorge

Hi Jorge

Its good to hear that. That monitor was excellent especially with all those inputs!

I can hear the power on the PSU (fans spin but will check if everything else gets warm in a few moments)

EDIT - just checked - the cpu gets warm so motherboard gets power. Someone help!

I get no picture on the monitor - tried different monitors.

my guess is to try find the bios for the Mobo. I will be happy to program it for you if you send me the eprom and the .bin file to me. dont want money only postage costs. I also can do the mod on dead Dallas bat. once more, only postage costs to send it back to you

The PC has been running for a good few hours to let the Dallas battery charge.

Afaik Dallas RCT's are no rechargable, and even "new" ones are likelly to be depleated of battery power, as they are not new manufactured.

Best to try and follow http://www.mcamafia.de/mcapage0/dsrework.htm to modify the Dallas RTC with an external new CR2032.

I have a Soyo 5ctu that also as a Dallas rtc and didn't even boot without the modification above to add a new battery.

jcarvalho wrote:

my guess is to try find the bios for the Mobo. I will be happy to program it for you if you send me the eprom and the .bin file to me. dont want money only postage costs. I also can do the mod on dead Dallas bat. once more, only postage costs to send it back to you

Hi Jorge. Thank you so much for your kind offer. I am going try modding the dallas rtc battery then i will get back to you. I will send you a pm later today

limboy777 wrote:

jcarvalho wrote:

my guess is to try find the bios for the Mobo. I will be happy to program it for you if you send me the eprom and the .bin file to me. dont want money only postage costs. I also can do the mod on dead Dallas bat. once more, only postage costs to send it back to you

Hi Jorge. Thank you so much for your kind offer. I am going try modding the dallas rtc battery then i will get back to you. I will send you a pm later today

No problem, we need to help each other... I have done that procedure in my Dallas bat. using also a coin bat. holder and double face tape ho hold both pieces from a pentium1 mobo and it is working great...

Thats excellent. I have a spare dallas battery so will try it myself and if that doesnt work then we will try the bios reflash
Where do i get the bin file?

A good friend of mine gave me this link with BIOS dumps
http://phantom.sannata.ru/software/
http://sannata.ru/bios/
I think that you wll find yours in 486 folder!!! I found acompatible here 😀 ... but didnt worked after all 🙁

jcarvalho wrote:

A good friend of mine gave me this link with BIOS dumps http://phantom.sannata.ru/software/ http://sannata.ru/bios/ I think that […]
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A good friend of mine gave me this link with BIOS dumps
http://phantom.sannata.ru/software/
http://sannata.ru/bios/
I think that you wll find yours in 486 folder!!! I found acompatible here 😀 ... but didnt worked after all 🙁

Thanks I have sent a PM. I appreciate your time and help.

I also have a question re VRAM. As I get power but a black screen, I suspect there may also be a possibilty with the VRAM chips not being fully functioning. The ones installed are in this folder:

http://postimg.org/image/3qo6xzt6j/

I have some spare (more than likely lower memory - these are in this folder:

http://postimg.org/image/cf4v4rn8r/
http://postimg.org/image/rcdc5s0h7/

are they compatible?

Take those out you have installed. And try it with the ones that are soldered in the mainboard. Also these Rams are 60ns.. Trying to keep them on 60ns.. Otherwise the ram can be slower if 70ns are installed.

The problem with you motherboard bios, you could try to make a *.BIN dump from the older chip, and try to program a new eprom with it.. Maybe you would have luck.. Otherwise you have to find a new bios program for it.

Robin4 wrote:

Take those out you have installed. And try it with the ones that are soldered in the mainboard. Also these Rams are 60ns.. Trying to keep them on 60ns.. Otherwise the ram can be slower if 70ns are installed.

The problem with you motherboard bios, you could try to make a *.BIN dump from the older chip, and try to program a new eprom with it.. Maybe you would have luck.. Otherwise you have to find a new bios program for it.

thanks for your reply. Are my ram chips 70 and the soldered ones 60? (Is 60ns faster than 70)?.

What do you mean by bios program?

About the memory, yes the 60ns are faster.. If you put 70ns near them, the 60ns chips will also running at 70ns.. So when you installing slower chips on a board with faster memory, you are making them slower..

http://postimg.org/image/3qo6xzt6j/
This is good..

The bios program to boot your computer is in the ROM on your motherboard.. You can try to dump it, and write it to a new chip that can be erased.. It could work with the new chip, but it also it can fail..

If the programmed chip with your older bios is bad (corrupted) you have to find the orignal one that the program code is still intact. Then you program a new eprom with it.. Then replace your old chip.