DKB1240 crashing

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Tajmaster

Tajmaster

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:sos:please:

https://www.amibay.com/showthread.php?t=50873&page=2

I got this yesterday, and Im having problems :-(

The Amiga constantly freezes with this card in.
Ive tried it on 2 A1200's (both recapped, and previously used with a RAM card and a Blizzard respectivly).
Tried on 3.0 and 3.1 ROMs
Tried with and without RAM
Tried different RAM sticks
Tried different PSUs
Only have a mouse/PSU/AV leads plugged in.
Tried with hard drive unplugged.
Edge connecter on board and Amigas cleaned with IPA.

It only has 2 jumpers that I can see (one for the FPU clock and one for turning the RTC on and off, Ive tried changing these too)

It freezes everytime I switch on the Amiga, usually within seconds of switching on, sometimes it will get to WB then freeze.

Can anyone help? Any ideas what it could be?

The only constant is the DKB. I fear its faulty :-(:-(:-( :help::help:
 
What Rev are the MBs you used and also
what PSU are you using..

:coffee:
 
The socketed oscillators never really good contact with the sockets.. I removed the oscillators and slightly curved the legs for better contact and grip... Never had any issues since :)
 
ChrisUnionNJ said:
What Rev are the MBs you used and also
what PSU are you using..

:coffee:
Click to expand...

A 1d1 and a 1d4 :)
Im using 2 heavy duty 60W types, both were used on these systems when they had the Blizzard and RAM cards in before.

---------- Post added at 22:24 ---------- Previous post was at 22:23 ----------
ptp170 said:
The socketed oscillators never really good contact with the sockets.. I removed the oscillators and slightly curved the legs for better contact and grip... Never had any issues since :)
Click to expand...
One of the oscillators can be removed, the other is soldered in. The socketed one is in solid (I think its used for an FPU though)

---------- Post added at 22:30 ---------- Previous post was at 22:24 ----------

I removed the socketed oscillator just now, no change.
Could the CPU be faulty?
 
Is the FPU socketed, can you remove that (and the oscillator for the FPU too)
 
fitzsteve said:
Is the FPU socketed, can you remove that (and the oscillator for the FPU too)
Click to expand...
It doesnt have an FPU installed Steve :) It did have the oscillator for it but Ive removed that tonight and it made no change :(
 
Is there also an FPU jumper you can set to 'No FPU' ?
 
Tajmaster said:
Edge connecter on board and Amigas cleaned with IPA.
Click to expand...

I'd do this again. Be fairly ruthless with the brush you use. I used to have one of these cards and it was very flaky, sometimes crashed, sometimes didn't even power on. Took a toothbrush and scrubbed the edge connector on it and it sprang into life.

On mine, the contacts had developed so much cruft on them that a gentle wipe with IPA and a paintbrush wasn't making a jot of difference. It really did need a good scrubbing. Might be worth a go.

:thumbsup:
 
There shouldn't be a secondary oscillator in place if there is no FPU... Remove the oscillator closest to the edge connector and set the XTAL1 jumper to CPU
 
I have a 1D4 and a 2B and it only worked on the 1D4
and I used A 300 watt PSU also if my simm came
lose it would give me problems.


:coffee:
 
ChrisUnionNJ said:
I have a 1D4 and a 2B and it only worked on the 1D4
and I used A 300 watt PSU also if my simm came
lose it would give me problems.


:coffee:
Click to expand...

That's a very good point. It's worth cleaning the SIMM contacts as well, they can get pretty grotty, too.
 
AndyLandy said:
Tajmaster said:
Edge connecter on board and Amigas cleaned with IPA.
Click to expand...

I'd do this again. Be fairly ruthless with the brush you use. I used to have one of these cards and it was very flaky, sometimes crashed, sometimes didn't even power on. Took a toothbrush and scrubbed the edge connector on it and it sprang into life.

On mine, the contacts had developed so much cruft on them that a gentle wipe with IPA and a paintbrush wasn't making a jot of difference. It really did need a good scrubbing. Might be worth a go.

:thumbsup:
Click to expand...

Ill scrub the CPU and SIMM connnector again when I get home :thumbsup:

---------- Post added at 08:17 ---------- Previous post was at 08:16 ----------
ChrisUnionNJ said:
I have a 1D4 and a 2B and it only worked on the 1D4
and I used A 300 watt PSU also if my simm came
lose it would give me problems.


:coffee:
Click to expand...
The SIMM socket is solid, no broken clips and it sits in the socket firmley :)

---------- Post added at 08:18 ---------- Previous post was at 08:17 ----------
ptp170 said:
There shouldn't be a secondary oscillator in place if there is no FPU... Remove the oscillator closest to the edge connector and set the XTAL1 jumper to CPU
Click to expand...
The oscillator has been removed and the jumper set to "CPU", still no change :(

Could this be a dodgy CPU??:blink:
 
OK, Ive scrubbed the connector on the A1200 and on the accelerator card, its still crashing randomly and very frequently :blink:

I dunno what it could be?? Could it be a dodgy CPU??

Im going to have to PM the seller if I cant get it resolved :(
 
@Taj

1. Is there a heat-sink on the CPU, if not there should be
2. Power, I would hook up a 300w ATX to ensure it is not a lack of power*


*It is entirely possible that the 5 volts might be just a tad low or a tad noisy for the operation of the Cobra / DKB1240

Once you have isolated the above, change the PS2 SIMM and retry - pick a 60ns FPM it matters not the size of the RAM, the operation of the unit.
 
try to reflash the rom. It helped a friend of mine with the same board!
Sometimes they get corrupted.
I can give you a contents if you want ,your serial number will not be the same though.
Cheers.
 
Marmes said:
try to reflash the rom. It helped a friend of mine with the same board!
Sometimes they get corrupted.
I can give you a contents if you want ,your serial number will not be the same though.
Cheers.
Click to expand...
I could try, if it can stay stable for long enough (it sometimes does but rarley). I have had a look here: http://amiga.resource.cx/exp/dkb1240

Apparently the Ferret disk has the ROM update, is that true? If not, how would I update the ROM?
 
Tajmaster said:
Marmes said:
try to reflash the rom. It helped a friend of mine with the same board!
Sometimes they get corrupted.
I can give you a contents if you want ,your serial number will not be the same though.
Cheers.
Click to expand...
I could try, if it can stay stable for long enough (it sometimes does but rarley). I have had a look here: http://amiga.resource.cx/exp/dkb1240

Apparently the Ferret disk has the ROM update, is that true? If not, how would I update the ROM?
Click to expand...

29C I believe it's an eeprom
So you need to just run the software. but if the rest of the rom is corrupted you will need a new one and a programmer.
Hope this is the problem, because it's easy to repair :)
Here is mine! I have the bad habit of backing up all eeproms and flashes of all cards I owned. :)
 

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