Re: New Echoplex

[Matthias Grob <matilists@atarde.com.br>]

this means that the processor and most of the digital part runs

and possibly the CODEC does not (the other square chip)

it starts up at one crystal frequency and then switches to the other at the end of the loop circus, which is when your crashes now.

On 7 Oct 2008, at 07:50, Daniel Hegarty wrote:

Hey Matthias,

Thanks for you fast reply!

Unfortunately things have gone from bad to worse. I knocked on all the chips and gently manipulated the board but nothing seemed to make a difference. When I put it into test mode and generated the 60hz signal its just a wall of distorted hiss!

I re-seated all the EPROMS without any difficulty, and they've all sat in nicely with no bent pins or anything. But..... now when it boots it just loops around the LOOP IV scrolling on the display and then re-boots again. It repeats this cycle endlessly!

Oh dear......

Thanks again

Daniel

On 7 Oct 2008, at 00:06, Matthias Grob wrote:

EPROMs have labels on them... 

any chip on a socket can be lifted a little (better not take it out completely) with a screwdriver on the side and then pushed back

its harder with the two square chips, since you can only insert a fine thing in two corner and the socket may be forced... there is a special tool for those.

contact spray is another method.

since its working correctly sometimes, a bad contact is quite likely

often it can be produced or "fixed" by just bending the board or hitting on it in different places (softly drop the back of a screw driver on chips) and thus aproximate the bad spot\

good luck!

and sorry for the confusion

some of the parts went out of fabrication years ago, so "new" is relative...

Matthias

On 6 Oct 2008, at 19:07, Travis Hartnett wrote:

I can't recall where they are right now.  Whenever I had to reseat them, it was in the process of doing an upgrade, so I was holding the two new EPROMs in hand, so it was a simple matter to find the two things already on the board that looked like the new ones.  Maybe someone else can chime in with a diagram, since I'm unable to find one online.

TH

On Mon, Oct 6, 2008 at 2:58 PM, Daniel Hegarty <danielphegarty@googlemail.com> wrote:

This will sound stupid but..... which bits are the ERPOMS and how would i go about re-seating them?

Thanks

D