English Amiga Board


Go Back   English Amiga Board > Support > support.Hardware

 
 
Thread Tools
Old 03 June 2018, 10:22   #61
CRP
Registered User

 
Join Date: May 2018
Location: Milano
Posts: 56
sorry I used the wrong words, here is what I did in order:
1) connected usb-to-ttl adapter to my pc, and there I connected tx and rx pins to make a loopback and verify that the adapter is working, which it is.
2) connected rs232-to-ttl adapter to the above, and repeated loopback test at db9 connector, again everything ok.
3) connected amiga serial port to rs232 adapter, pins tx->rx, rx->tx and gnd->gnd, but when I turn on amiga I get no consistent output, just occasionally random characters, but they look more like the result of noise to me than an incorrectly transferred output from the amiga; nonetheless, diagrom's status line shows serial 9600 bps, so it does recognize something at the serial port.
4) suspecting that the ami's serial port is not working, built a loopback connector for the amiga, connecting pins 2-3, 4-5-6, 8-20-22 but did not attach the leds to +12v and -12v pins, started diagrom's serial test and they all fail, although test passes are much quicker than when nothing is attached to serial port, so again I guess this means that something is recognized.

So my question is: should I first get leds to complete the loopback, or should I move straight to debugging the components in the amiga around the rs232 port? I already swapped the CIAs, and read I should also check caps and resistors, and finally U38 and U39.

thanks


Quote:
Originally Posted by Chucky View Post
you should not SHORT anything.. you should CROSS so TX on the Amiga is connected to the RX on the PC and the RX on the Amiga is connected to TX on the PC..

if you get an echo. you have shorted and done it wrong as when you send data. it is getting back to the PC again.. and thats wrong and a reason why you do not get any data.
CRP is offline  
Old 03 June 2018, 10:48   #62
Chucky
Registered User

Chucky's Avatar
 
Join Date: Mar 2015
Location: Karlstad / Sweden
Age: 46
Posts: 473
Diagrom always say 9600 bps unless you have a loopback adapter attached (then it says LOOP)

so. if you get random data and are using 9600 BPS on your PC.. paula is not getting all 8 bits needed to produce serial data.. so I would do a continuty-test on all datapins from paula.
Chucky is offline  
Old 03 June 2018, 13:33   #63
tnt23
Registered User
tnt23's Avatar
 
Join Date: Feb 2008
Location: Saint-Petersburg / Russia
Posts: 321
Quote:
Originally Posted by CRP View Post
I switched the two CIAs, but nothing changed. Can I assume the two rs232 chips are fried?
On an A500 I was resurrecting for a friend, either U38 or U39 was bad and would not let the computer start normally. Got extremely hot right from turning power on. (We just chopped both off, did not bother having working RS232). Could be worth checking.
tnt23 is offline  
Old 03 June 2018, 14:51   #64
plasmab
Banned
plasmab's Avatar
 
Join Date: Sep 2016
Location: UK
Posts: 2,917
DiagROM V1.0 Released

The CIA does not do serial on the amiga. It’s Paula

EDIT: the CIA’s are just used for the handshakes which DiagROM does not use
plasmab is offline  
Old 03 June 2018, 15:34   #65
Chucky
Registered User

Chucky's Avatar
 
Join Date: Mar 2015
Location: Karlstad / Sweden
Age: 46
Posts: 473
I do not think the TTLs are dead. they are hard to kill. I think that you have issues with datalines to paula it seems that you can get picture on diagrom. do a audiotest and listen.. same signals are used there.

Paula handles serial.. NOT CIA.. this is a common misstake.
Chucky is offline  
Old 06 June 2018, 04:31   #66
crashserious
Registered User

 
Join Date: May 2018
Location: Beverly HIlls, Ca
Posts: 17
Minor update. I desoldered a bit over half the memory chips today (I was finding inconsistencies I couldn't figure out and had new ones in hand.


I did find that CAS on the higher numbered 6 of 32 (Last?) chips was missing completely. Which lead me to a bad CAS trace between the 7th and 6th highest numbered chip. It does sort of appear to have been some form of corrosion, though there's no damage close to the battery so I can't account for it's source.



Getting there. A rev 4.5 schematic would come in so handy right now since it has more chips than a rev 6. grrrr.



Quote:
Originally Posted by Chucky View Post
this is most likely not a memorychip. but a trace that is bad.
but IF memory (it can draw thebit all high.. or all low) a easy method figuring out what memorychip it is. is to short the datapins of the memory ICs and look on screen (as it is updated in realtime) and see what chip you can short without 2 stripes gets changed. then you have found the chip.

but now I am quite surtain it is a trace or pullup/down resistor.
crashserious is offline  
Old 09 June 2018, 04:45   #67
crashserious
Registered User

 
Join Date: May 2018
Location: Beverly HIlls, Ca
Posts: 17
Making progress!!! It's no longer displaying a green screen! Now it's YELLOW with teh Kickstart ROM in, and DIAGROM appears to work just fine!

I replaced all the RAM chips for good measure (and socketed them) and fixed a CAS trace between the 25th and 26th RAM chip causing CAS to not be present of the last 6 chips. I replaced all the 74244's, 74245's and 74737's.


I also had to fix a data line (D8 I believe) from the 73737 between the ROM and RAM. (I may have damaged this trace replacing the 74737)

The tests all work as far as I can tell. but the Fast Mem (slow or fast) reports: "Bad Block start at $FFFFFFFF and ends at $00000003 with a size of 0KB".

The serial logs prior to this I don't see issues.

(One final tidbit that I tried on a whim.... I cut J500 since I also have a 8Mb Zorro II IDE card to put in this thing. I get greeted with a kickstart screen!!!! booting with gotek floppy works, after enabling the RAM on the Alfa Data AT-BUS 2008 by un-jumpering JMOFF it sees the memory and the IDE CF card is formatting now. The A2090A doesn't seem to work, but that could be a bad HDD I bought off ebay, since that drive is very small, I may not care a lot about it.)
Attached Thumbnails
Click image for larger version

Name:	20180608_192102[1].jpg
Views:	90
Size:	983.7 KB
ID:	58520  

Last edited by crashserious; 09 June 2018 at 22:09. Reason: adding info to avoid reposts, but keep information accurate.
crashserious is offline  
Old 11 June 2018, 00:20   #68
Chucky
Registered User

Chucky's Avatar
 
Join Date: Mar 2015
Location: Karlstad / Sweden
Age: 46
Posts: 473
Either there is a bug.. or you do not have memory at that location..
I am in process of making a completley new memorytest..
Chucky is offline  
Old 16 June 2018, 05:13   #69
crashserious
Registered User

 
Join Date: May 2018
Location: Beverly HIlls, Ca
Posts: 17
I've been thinking of getting a Programmer myself. I'd be willing to put the jumper back in and test it, if that helps.


At the risk of turning this into a request thread, I'd love to see some sort of indicator of which bar is which chip. I knew there were 32 of them-- but I didn't know what was where.



Quote:
Originally Posted by Chucky View Post
Either there is a bug.. or you do not have memory at that location..
I am in process of making a completley new memorytest..
crashserious is offline  
Old 24 June 2018, 22:10   #70
CRP
Registered User

 
Join Date: May 2018
Location: Milano
Posts: 56
I just got myself a cheap USB scope. The TTL serial signal comes out of Paula's pin 40 correctly. From there it goes into pin 9 of the MC 1488. The same signal, converted to RS232 levels, should come out of pin 8, but here all I get is a constant +12V signal, which should correspond to logical 0. So I am assuming that the MC1488 chip is dead. I will replace it and see what happens next.

UPDATE: replaced MC1488, now serial works fine

Quote:
Originally Posted by Chucky View Post
I do not think the TTLs are dead. they are hard to kill. I think that you have issues with datalines to paula it seems that you can get picture on diagrom. do a audiotest and listen.. same signals are used there.

Paula handles serial.. NOT CIA.. this is a common misstake.

Last edited by CRP; 29 June 2018 at 00:51.
CRP is offline  
Old 29 June 2018, 02:40   #71
cerebralcortex
Registered User

 
Join Date: Jun 2018
Location: Virginia USA
Posts: 1
Question Need some help with chipmem error output please...

I just received my Diagrom from GGLABS and I'm ready to fix several of my old A500 boards each with different issues. First system is a 6A with a chip mem error. I removed 1 chip where there seemed to be some liquid (coffee?) damage and replaced with new MEM chip but i think there is another or more that will need to be replaced. Can someone please help my figure out what this output is telling me. I looked all over the web and didn't find a "guide" for the Diagrom, if someone can please point me to one or good reference guides I would be very grateful. I REALLY want to fix these! See attached pic of Extended ChipMEM test.


CerebralCortex
Attached Thumbnails
Click image for larger version

Name:	20180628_181714.jpg
Views:	91
Size:	364.3 KB
ID:	58692  
cerebralcortex is offline  
Old 21 October 2018, 04:52   #72
nolunchman
Registered User

 
Join Date: Aug 2018
Location: Hayward
Posts: 47
my diagrom set works on a healthy 3000 motherboard and i am trying to use it on a damaged board (battery damage). i get no output from the serial port. although diagrom is not working with this board, that still may give clues where to look. what parts of the motherboard does diagrom need to still be functioning?
nolunchman is offline  
Old 21 October 2018, 12:49   #73
Chucky
Registered User

Chucky's Avatar
 
Join Date: Mar 2015
Location: Karlstad / Sweden
Age: 46
Posts: 473
Quote:
Originally Posted by cerebralcortex View Post
I just received my Diagrom from GGLABS and I'm ready to fix several of my old A500 boards each with different issues. First system is a 6A with a chip mem error. I removed 1 chip where there seemed to be some liquid (coffee?) damage and replaced with new MEM chip but i think there is another or more that will need to be replaced. Can someone please help my figure out what this output is telling me. I looked all over the web and didn't find a "guide" for the Diagrom, if someone can please point me to one or good reference guides I would be very grateful. I REALLY want to fix these! See attached pic of Extended ChipMEM test.


CerebralCortex
Addresserror can be much different things. this is a error exception so something is screwed.. my guess it is something handling memory.

also. it is not THAT often chips die. more traces/passives.
Chucky is offline  
Old 21 October 2018, 12:51   #74
Chucky
Registered User

Chucky's Avatar
 
Join Date: Mar 2015
Location: Karlstad / Sweden
Age: 46
Posts: 473
Quote:
Originally Posted by nolunchman View Post
my diagrom set works on a healthy 3000 motherboard and i am trying to use it on a damaged board (battery damage). i get no output from the serial port. although diagrom is not working with this board, that still may give clues where to look. what parts of the motherboard does diagrom need to still be functioning?
Batterydamage on A3000 usually affects Paula, Denise etc. with datalines bad to paula serialoutput can be broken then it is harder. then you can check if powerled flahes, so you know that diagrom can run. then it is back to "oldfashioned" troubleshooting checking datalines etc to the chipset.
Chucky is offline  
Old 22 October 2018, 03:04   #75
nolunchman
Registered User

 
Join Date: Aug 2018
Location: Hayward
Posts: 47
Quote:
Originally Posted by Chucky View Post
Batterydamage on A3000 usually affects Paula, Denise etc.
what about a 3000T motherboard? aside from the kick roms, the chips near the batt are the FPU and a few other unfamiliar ICs...
i've replaced the 40pin sockets and and jumped the traces but diagrom still doesn't output to serial. the paula and denise chips are on the opposite end of the motherboard.

here is a pic of the chips near the battery

https://1drv.ms/u/s!AnzbjMU9nUZpixIZhd8fols1iPke

Last edited by nolunchman; 22 October 2018 at 03:18.
nolunchman is offline  
Old 25 October 2018, 23:36   #76
Chucky
Registered User

Chucky's Avatar
 
Join Date: Mar 2015
Location: Karlstad / Sweden
Age: 46
Posts: 473
does powerled staert to flash?

and not sure but you maybe need to change some jumper is fpu is missing
cant remember now
Chucky is offline  
Old 26 October 2018, 01:45   #77
amigakit.com
Registered User

amigakit.com's Avatar
 
Join Date: Aug 2004
Location: www.amigakit.com
Posts: 1,742
@Chucky

The ROMs are great work.
amigakit.com is offline  
Old 26 October 2018, 20:35   #78
nogginthenog
Amigan

 
Join Date: Feb 2012
Location: London
Posts: 671
@Amigakit - you should sell them (with a few € going back to Chucky of course)
nogginthenog is offline  
Old 26 October 2018, 21:16   #79
Chucky
Registered User

Chucky's Avatar
 
Join Date: Mar 2015
Location: Karlstad / Sweden
Age: 46
Posts: 473
V1.1 out any day..
Chucky is offline  
Old 27 October 2018, 19:13   #80
Chucky
Registered User

Chucky's Avatar
 
Join Date: Mar 2015
Location: Karlstad / Sweden
Age: 46
Posts: 473
http://www.diagrom.com/index.php/201...v1-1-released/
Chucky 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
DiagROM V0.9 Out Chucky support.Hardware 14 31 August 2017 16:35
DiagROM V0.8 Chucky support.Hardware 3 27 October 2016 14:49
New "Stable" of my DiagROM Chucky support.Hardware 4 07 August 2016 11:28
In search for defective custom ICs to test DiagROM Chucky support.Hardware 2 11 May 2015 19:49
Never released??? tomcat666 project.aGTW 18 18 January 2010 15:44

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 04:43.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.
Page generated in 0.11905 seconds with 14 queries