Dead FALCON (SOLVED)

[zfrenchy]

I need help troubleshooting my Falcon.

I was ready for installing the DFB1X booster, following the tuto, I start my falcon before installing anything, but the falcon didn't start, white screen, no activity !

After an inspection, nothing blowup on the board, 12V present on the floppy drive, and 5V on multiple IC.

removing keybaord, IDE card, floppy drive, external SCSI, still no boot, white screeen sometime, but mainly black screen now.

after a time, the screen showing this patern with vertical lines, sometime, but now completely black, no more any activity!

20251204_125423.jpg (212.37 KiB) Viewed 161 times

I tried to put the diagnostic cartridge and connect another computer in VT52, but nothing, DEAD !

Screen Shot 12-04-25 at 02.36 PM.PNG (152.35 KiB) Viewed 161 times

What is my next step ? I have oscilloscope or a logic analyzer to work with, but my knowledge on these materiel is limited.

I used a thermal cam and nothing is excessively hot

[mikro]

You can follow my posts here on the forum, most importantly start with the Exxos guide for the basics (clocks going to all chips, address/data bus activity etc). Could be a dead Videl but that's too soon to tell. Any clock patch installed?

[zfrenchy]

more info ...

The diagnostic cartridge is working, but the way to make working is weird:
1- power down
2- install the cartridge
3- disconnect the 3-in-1 video adapter
4- power up
5- connect the 3-in-1
All good

But, if I try the same sequence without the diag cartridge (boot on TOS) nothing happen, white screen.

How can I checked if the TOS is still good ?

[zfrenchy]

I installed the DFB1X:

jumper JC1 - short: 40Mhz
jumper BS1 - short: Bank 0 (TOS 4.04)
jumper option - short: CPU at 16Mhz
jumper disable - short: Booster disable


ALL WORKING, booting as normal.

Is that mean the original TOS on board is dead ? How ?

[HigashiJun]

Do you have the jumper installed on the expansion header when your DF1BX is removed ?

[zfrenchy]

Do you have the jumper installed on the expansion header when your DF1BX is removed ?

the header on the motherboard where the DFB1x goes ?

[HigashiJun]

the header on the motherboard where the DFB1x goes ?

Yes.

[zfrenchy]

Do you have the jumper installed on the expansion header when your DF1BX is removed ?

I guess you are talking about this ...

20240526_151556.jpg (297.42 KiB) Viewed 130 times

NOPE, I didn't !!!!

good catch ! Problem SOLVED !

[HigashiJun]

[zfrenchy]

At least I learn two things:
1- always make a note of what you do
2- how to set VT52 serial comm between atari st and falcon !