English Amiga Board


Go Back   English Amiga Board > Support > support.Hardware

 
 
Thread Tools
Old 03 October 2019, 01:07   #1
Glen M
Registered User

 
Join Date: May 2017
Location: Belfast
Posts: 497
M1202 memory expansion help please

I recently bought a M1202 ram expansion from ebay sold as faulty.

It has 4mb of ram and fpu fitted. There is also a coin cell battery for the clock.

I noticed on the eBay add that the crystal wasn't fitted for the fpu and I suspected that to be the problem as to why the seller couldn't get this card to work.

First thing i did was to remove the FPU and it posted but brought up a screen saying the expansion was faulty.

I then looked over the board with my magnifying glass and found a few dry solder joints so I reflowed them tried it again and it booted showing the 4mb of fast ram. Happy days I've fixed it I thought....

I then thought maybe I'll try that FPU again so I put it back in and back to black screen but now since removing it I've only been able to get the Amiga to post once. All I get is a black screen quickly followed by no signal on the TV generally followed by a reset and either black screen again or some garbage on screen. I've tried reseating all chips that are socketed with no change and also reseated the ram module. I do note there is some slight damage on one of the ram chips so possibly a bad stick of ram? Its only 4mb so I was going to get an 8mb stick anyway.

Does anyone have a link showing how to set the jumpers on this board just in case something is set wrong.

p.s. I've also tried cleaning the edge connector in the 1200 and the slot on the card, they were a bit dirty but no difference.
Glen M is offline  
Old 03 October 2019, 01:44   #2
lesta_smsc
Registered User

lesta_smsc's Avatar
 
Join Date: Feb 2012
Location: United Kingdom
Posts: 1,830
Is this of any help?

https://www.bigbookofamigahardware.c...t.aspx?id=1007

Sent from my SM-G925F using Tapatalk
lesta_smsc is offline  
Old 03 October 2019, 01:51   #3
Glen M
Registered User

 
Join Date: May 2017
Location: Belfast
Posts: 497
thanks, that link has the manual.

I've since tried the card in my main A1200 and its booted fine and has been running ok for the last 30 minutes or so. I'm thinking its maybe still a dirty connection on my 2nd A1200 for which this card was intended.
Glen M is offline  
Old 03 October 2019, 01:52   #4
lesta_smsc
Registered User

lesta_smsc's Avatar
 
Join Date: Feb 2012
Location: United Kingdom
Posts: 1,830
That's great news. How much did you buy it for?

Sent from my SM-G925F using Tapatalk
lesta_smsc is offline  
Old 03 October 2019, 02:05   #5
Glen M
Registered User

 
Join Date: May 2017
Location: Belfast
Posts: 497
Quote:
Originally Posted by lesta_smsc View Post
That's great news. How much did you buy it for?

Sent from my SM-G925F using Tapatalk
Paid £30 including postage. Did OK I think.
Glen M is offline  
Old 03 October 2019, 13:37   #6
Glen M
Registered User

 
Join Date: May 2017
Location: Belfast
Posts: 497
Just thinking out loud here but could it be that my spare 1200 needs a recap? I've ordered the caps and hopefully will be doing it this weekend.

Or could it be the timing fix needs done i.e. the fix i had to do to my main 1200 to get it to boot with the ACA1233n?
Glen M is offline  
Old 04 October 2019, 11:40   #7
Glen M
Registered User

 
Join Date: May 2017
Location: Belfast
Posts: 497
Just to let you lot know and anyone else who may be searching for resolutions to such problems in the future I fixed it. But you will not believe just how stupid it was. To fix it all I had to do was to pull the card back off the edge connector slightly, maybe 2-3mm back. Works fine now every time but if I push it back in fully it fails.

What is it with these edge connectors not making good contact? Is it a failing connector on the memory expansion or would it always of been bad? All I can guess is that the connector is going to far over the pins on the 1200 loosing contact.
Glen M is offline  
Old 04 October 2019, 21:40   #8
paul1981
Registered User

paul1981's Avatar
 
Join Date: Oct 2013
Location: England
Posts: 178
Could be dirty edge connector contacts on the A1200? I have had that before. I like to use WD-40 on those (applied with a cloth of course, or there would be a mess wouldn't there). Normally you'll see green copper oxide on the cloth.
paul1981 is offline  
Old 07 October 2019, 16:50   #9
Glen M
Registered User

 
Join Date: May 2017
Location: Belfast
Posts: 497
Quote:
Originally Posted by paul1981 View Post
Could be dirty edge connector contacts on the A1200? I have had that before. I like to use WD-40 on those (applied with a cloth of course, or there would be a mess wouldn't there). Normally you'll see green copper oxide on the cloth.
I've went over it with IPA and it took off a fair bit of dirt but the problem persists unless the card is pull out a few mm.

The machine also has various other minor issues that I'm putting down to bad capacitors. I have the replacements now, I just didn't get time at the weekend past to swap them out. Maybe do it between this evening and tomorrow evening. I'm going to do a video on it for my channel and recording such things just makes it take 2 or 3 times longer.
Glen M is offline  
 


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Looking for memory expansion for A1200 paulo_becas MarketPlace 1 12 April 2010 15:10
Looking for some memory expansion to my 1200 paulo_becas MarketPlace 0 03 March 2010 17:21
For Sale: Gasteiner M1202 RAM/RTC A1200 expansion Voz79 MarketPlace 9 05 December 2009 13:55
Memory expansion for A500 source support.Hardware 2 10 August 2009 22:54
A4000 Memory expansion manicx MarketPlace 2 24 July 2003 16:32

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +2. The time now is 05:34.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Page generated in 0.06703 seconds with 15 queries