Mega STE keyboard problem

[Fletch]

I recently purchased a Mega STe from a fellow that thought the keyboard had died. The Mega basically just clicks continuously when the keyboard is attached and it does not recognize the keyboard or mouse.

 

So.... I ordered a brand new keyboard from Best Electronics and when I hooked it up I have the same problem. I took the Mega apart and reseated all of the socketed chips but that did not seem to make any difference.

 

Does anyone have any advice on what may have gone wrong?

 

Thanks in advance.

 

Fletch

[+poobah]

I recently purchased a Mega STe from a fellow that thought the keyboard had died. The Mega basically just clicks continuously when the keyboard is attached and it does not recognize the keyboard or mouse.

 

So.... I ordered a brand new keyboard from Best Electronics and when I hooked it up I have the same problem. I took the Mega apart and reseated all of the socketed chips but that did not seem to make any difference.

 

Does anyone have any advice on what may have gone wrong?

 

Thanks in advance.

 

Fletch

 

Does it do the same thing with no keyboard attached?

[belboz]

Weren't there two 6850 UARTS used in the ST's. One for midi port, the other to communicate with the keyboard?

 

Pretty sure that is what was used. Don't have any schematics handy, but it could be the 6850 used to communicate with the keyboard controller is dead.

 

Pretty sure the picture below shows them. One is directly to the right of the keyboard connector, the other above it.

 

http://www.maedicke.de/atari/hardware/pictures/megaste_5.jpg

[Fletch]

Nope, only with the keyboard attached.

 

I recently purchased a Mega STe from a fellow that thought the keyboard had died. The Mega basically just clicks continuously when the keyboard is attached and it does not recognize the keyboard or mouse.

 

So.... I ordered a brand new keyboard from Best Electronics and when I hooked it up I have the same problem. I took the Mega apart and reseated all of the socketed chips but that did not seem to make any difference.

 

Does anyone have any advice on what may have gone wrong?

 

Thanks in advance.

 

Fletch

 

Does it do the same thing with no keyboard attached?

[Fletch]

I found the two chips. They look exactly the same so for giggles I swapped them around to see what happens. Sadly I get the same result.

 

I'm guessing I'm going to have send her away to Brad at Best or something if I want the Mega to live on. Maybe I'll just pop out the TOS roms and put them in my 1040 STE and build an adapter to use my new $110 keyboard.

 

I have such the luck

 

Fletch

 

 

Weren't there two 6850 UARTS used in the ST's. One for midi port, the other to communicate with the keyboard?

 

Pretty sure that is what was used. Don't have any schematics handy, but it could be the 6850 used to communicate with the keyboard controller is dead.

 

Pretty sure the picture below shows them. One is directly to the right of the keyboard connector, the other above it.

 

http://www.maedicke.de/atari/hardware/pictures/megaste_5.jpg

[belboz]

On my schematics for the Mega ST (not a Mega STE, but they are probably very similar) I see the signals for transmit and receive from the 6850 goes through an inductor (L9 on the Mega STE). There is a chance that is blown.

 

There are also a pull up resistor and some caps on the signals coming out of the 6850. Pin 6 is the transmit pin from the 6850 and pin 2 is the receive pin.

 

The troubleshooting section of the manual says that a keyboard not responding is generally related to the 6850 or the MFP chip.

 

You can also verify the signals on the 6 pin keyboard connector.

 

On the schematic it says.

 

Pin 1 = +5

Pin 2 = +5

Pin 3 = TX

Pin 4 = RX

Pin 5 = GND

Pin 6 = GND

[Fletch]

I think I'm just going to sell the Mega STe for parts. I'm going to keep the TOS 2.02 roms to put in my 1040STe, the disk drive (which I took out of my 1040STf), and the hard drive in case I can find a LINK or ADSCSI for a decent price.

 

So if anyone is interested in a semi functional Mega STe or parts make me an offer. If you want the brand new Keyboard with it I'd be willing to part that too, but I just paid $110 bucks for it so I'd want to recoup at least a decent portion of that if possible. I might just make an adapter to use that keyboard with my 1040STe if nobody needs a new keyboard.

 

I'd be willing to trade the Mega for a 1040ST power supply if anyone wants to work that deal. I need one of those.

 

Thanks in advance.

 

Fletch

 

 

On my schematics for the Mega ST (not a Mega STE, but they are probably very similar) I see the signals for transmit and receive from the 6850 goes through an inductor (L9 on the Mega STE). There is a chance that is blown.

 

There are also a pull up resistor and some caps on the signals coming out of the 6850. Pin 6 is the transmit pin from the 6850 and pin 2 is the receive pin.

 

The troubleshooting section of the manual says that a keyboard not responding is generally related to the 6850 or the MFP chip.

 

You can also verify the signals on the 6 pin keyboard connector.

 

On the schematic it says.

 

Pin 1 = +5

Pin 2 = +5

Pin 3 = TX

Pin 4 = RX

Pin 5 = GND

Pin 6 = GND

[Fletch]

The Mega is now sold.

 

Thanks for all of the help.

 

Fletch

[Fletch]

The Mega is now sold.

 

Thanks for all of the help.

 

Fletch

[Chandler]

did you actually change the cable from the keyboard to computer?

[Fletch]

did you actually change the cable from the keyboard to computer?

 

 

I sure did. It turned out to be a bad PSU. The fellow I sold it it to replaced the PSU and she apparently runs like a top.