EII can´t boot from the disk

[xmota]

EII Nr. 2 (used to work with SD, now broken)

- Logic Board Rev 0.1 (scanner 3.1, main EPROM 2.1. OS 3.1, 2x 5,25 floppy drives),
- RS422 piggy board inside
- memory expansion piggy board inside
- used to work with SD with no problems
- about 1 year ago some voices missed, later can not boot from the disk (no tac, tac, tac at the beginning)
- we checked the power supply and its connectors (as recommended), did not help

[dr.c]

I already answered that one. This you try lower software version ? (Easy with an EII)

[xmota]

Did you mean lower version of Scanner and main EPROM?

[dr.c]

Noooo, disquette !

[xmota]

It doesn´t try to read anything from the diskette. The disk does not start at all.

[dr.c]

Geee....

Is there anything written on the display ?

Tired to repeat again, and again :


First : take off the power supply, look under : the solderings of the Molex conncetor may be crackeled.
Take off the old solder and resolder after cleaning.


As well, the connector distributing the power to the boards, the one having the multicolour wires, mays be overheaten. You may see it by a brown trace. Try to clean the contacts with a special cleaner for printed circuits.

Put everything back in place.

Is there anything written on the display ?

[xmota]

Just Boot in progress, we already did everything you suggested with the power connectors, no result.

[dr.c]

Ahhhhh !!!!! At last, we have got something ! (Man, that was hard... )

Okay : this means that the main and scanner boards are not communicating.

I am EXTREMEY SURPRISED that the PSU trick doesn't work.

Can you please power the E2 and check one thing :

WITHOUT  a floppy : does the floppy reader blink (the LED, obviously).
If it blinks, does it blink fast; or slowwwwww

If it does not blink, does the motor start and stop (spinning of the diskette) ?

WITH a diskette : led blinking ? Fast/Slow ?

Does the motor start and stop (spinning of the diskette) ?

These are important topics, it telles where the mess starts

[xmota]

The LEDs of both drives together blink right after Power On (very shortly about 0,1 sec), no acoustic effects (motor does not start, heads do not move) with diskette or without the same.

We followed the service manual. The main processor does not start cpmmunication with the PIO (probably). M1 signal is cycled (square). We think that there is mess between main CPU and PIO or EPROM eventually.

[dr.c]

There are many socket problems, contacts. Take off the Z80 CTCs and put them back, as well the 6116 static rams. Otherways, you would need the debuggin eproms.

[xmota]

Well I´ve already took off all chips, clean the contacts and put them back (nice weekend by the way). What would the debugging EPROMs do for me (if I have them)?

[dr.c]

Debug Eproms would allow you to test the logics of the boards.

Well, I don't really know now what to tell....

[xmota]

Are they available somewhere?

[dr.c]

Naaa... I don't know, I didn't use them. The reason is very simple : the debug eproms are usefull only if the system works, otherways they are useless. Its a bait "the snake wich bites his tail". Well, sometimes, it may be usefull.

Sometimes, I banged under the machine with my flat hand and it restarted. A nightmare....

[Jim Stout]

I just had my PSU rebuild and I am having the same problem.

the drive come on for .01 sec then nothing.

The screen says "Emulator 2 Boot in Progress" but nothing going on.