My New EII, some problems, any suggestions?

[tomc]

Just got an EII yesterday.
1st few times switched on, it got to boot screen, and no further.
So I opened up, reseated a few memory ICs around what I think is first segment (IC13 area?) - used some deoxit and replaced.

Then this time, it booted up and all seemed good. A Bank loaded. I then tried to load a bank from another floppy, started loading, then after a bit froze and blanks screen.

Since then I have removed and reseated just about every IC on the digital board.

Generally all I get is black blocks on the top row of the LCD, nothing on second. And usually ALL of the LEDs lit.
about 1/10 times I might get the boot screen, but no further (doesnt try to read discs).

So in theory most of the machine is OK since I got as far as loading 1 bank.

Wondering if this is a bad connection somewhere.

Maybe RAM/Scanner problem?

Can any suggest anything I can try?
Which Ram ICs should I check first,
Any tips appreciated.
I am very good with electronics, however, not too familiar with EIIs (but learning fast!)

[tomc]

BTW, oddly, my boot up screen is unique(?)


  **Emu 3-1 SC ***
Mulhouse 1-02-90

custom? maybe just the message has been changed? (maybe Mulhouse is one of the previous owners?)

[sfbaytech]

These are classic symptoms of corrupt memory (that is why you have garbage displayed). If you are lucky it is just a memory chip, and your first task is to run the memory test (if you don't have a test floppy then you can download and burn a diagnostics eprom from the Yahoo group). If the test fails and it is not a chip (takes a bit of decoding and reference to the schematic to figure out which RAM chip) but is location sensitive it is often a corroded pin on the socket. The other thing that could be happening if memory tests good is that bad data is coming from the floppy, but if you have 2 drives you can isolate that (plus the diag eprom has a disk exerciser).

This is the easier stuff on an EII, and diagnosing the harder stuff is patience, a scope, and the schematic (and I have spent too many hours at that on EII's). You should also check your power rails (but don't start twiddling pots), with a common issue being dry joints/high resistance connections at the psu output.
 
Chris
www.thisoldsynth.com

[tomc]

if any one out there is listening (this is a quite forum!)

I am both a genius and an idiot,

I found, that after cleaning IC sockets, I put a Zilog back in wrong 

Fixed that, and now reliably boots each time.

But no sound
So I will run a memory test next

[dr.c]

Mulhouse is a damn city in Alsace ! And you live at 117 km (roughly 70 miles) of it, at Strasbourg !