Tandy 1000HX Won't Boot

[rorysl]

I tried to power up my HX the other day, hooked to a CRT Television with a video RCA composite cable and am getting no proper picture.

There are no error beeps on start-up, unit seems to power up fine. Power light comes on and stays on. 3.5" drive light comes on and stays on Number lock and Caps lock lights respond to their button presses.

Screen, however, is black with garbled white lines. These lines could be the white Dos text scrambled or could just be interference, I can't tell.

I've tried hitting F2 when starting the Tandy to see if that will restart TV mode with no luck.

I've also tried typing MODE TV once the computer has booted with no effect either.

I made a video of the booting process for reference: https://youtu.be/AGH4LsxKfJQ

Unfortunately I have no Tandy monitor to hook it up to test and see whether or not it is only the composite output affected.

Hoping someone here might be able to offer up some advice!

[digress]

Keyboard

The Tandy 1000 series computers have 12 function keys (analogous to modern PC keyboards) whose functions depend on the program you are running. Some function keys have special functions during boot up, if you press them right after the startup "beep", while MS-DOS loads

* F1 = Switches the computer into monochrome video mode.

* F2 = Switches the computer into composite/TV video mode (40 Column/200 scanline mode). This can also be achieved by issuing a MODE command from DOS.

* F3 = Reverses the drive references so B: becomes the primary drive, and A: becomes the secondary drive, this lets you start the computer from the B Drive.

* F4 = Starts the computer in slow (4 MHz) mode. This is useful if a program runs too fast or not at all in normal (8 MHz) mode.

[rorysl]

As noted in my OP, I've no monitor to hook it up to so F1 doesn't help me and I've attempted to use F2 and the MODE command with no luck. What is helpful from your reply, though, is the fact that the function keys must be pressed after the startup beep, which I didn't know. As I'm not getting a startup beep it appears to be a bigger issue than display.

 

Based on some preliminary research, it appears to be the power supply. In any case, I've got a guy looking at it. Will report back with results, for those interested.

[digress]

Is the volume turned up.? Check to see if the volume disc is damage too. Hx has built in dos in rom so it should boot. I have a hx here and when I first got it I couldn't get it out of monochrome mode till I found this info. Could be something loose inside shorting it too like a disk drive cable have inor slanted etc.

[rorysl]

Hey folks, well after some tinkering it looks like the power supply is fried. Anybody know if the power supply from an EX and an HX are transferrable -- practically the same computers so just wondering.