Dragon's Lair Fans - Arcade Lifestyle
General Chat => Technical Area => Topic started by: anunaki on November 24, 2013, 09:29:19 PM
-
Hi,
I picked up my DK cabinet from Tyrems place. Today I connected the board and powered it up. It wasn't working :( :(
I hear the startup sound but the image is all messed up and way to small .
I measered the voltages on the board (edge connector) 5,03 V and 11.96V and checked the dipswitches.
I'm not really that technical unfortunately, but are there some easy to do checks I could perform?
Cheers, Patrick
-
Try contacting RobinHolland, maybe he can help you, he is a pcb wizzard 8)
-
Try reseating all the roms, and the flat cables.... sometimes that helps...
-
I did some googling and I found I have to check the 5V on the IC's instead of the edge connector. It could be the voltage needs to be a little higher. There should be an adjustment pot inside the power supply.
So what I can do is:
- measure the voltage on the IC
- reseat ICs
Could The issue with the image being too small be fixed with the capkit?
-
that could be, of if you are unlucky its the ceramic adjustment in the horizontal width coil that is broken..
you can try to adjust that to see if id does make any difference..
(http://www.opdenkelder.com/pics/HWC.png)
DON'T use a alanwrench in that thing ! us a TV adjustment tool (plastic)
http://www.youtube.com/watch?v=QuTlChCko4k
Let's first do the capkit, then adjust the B+ to 108 volts and then screw around with other pots
you say too small, question is, is it horizontally too small or vertically ?
-
The picture is not to clear I think, but if you look at it, you see the image is too small horizontally and vertically
-
Maybe this will help: http://www.brasington.org/arcade/tech/dk/
And congrats with your cabinet, would love to see some pictures.
-
tx
there will be some pics for sure, I'm a little short on time these days
-
I'm trying to reseat the EPROMs and the very 1st one I do leaves one leg behind in the socket :( :( :(. This never happened before to me and I'm really sad it happens with my DK board.
so now I'm pretty much lost in my attempts to see if it works, because I have no way to burn a new 2532 eprom
my batronix device can only read it
is there one of you guys able to get me a new 5A eprom
-
Take an old resistor or cap and clip off one leg, solder it to the left over of the broken off pin. Clip off the leg so that it at the same level as the other legs of the EPROM, now, at least, you can still read it........
....or just get the image from the internet :)
How do you remove chips ? FORGET every tool ever made for removing DIL chips. Use a small screwdriver and lift it up slowly and take turn on both sides of the chip.
-
that's what I do, I use the screwdriver all the time
never had any problem doing this
about the image: My device cannot brun this kind of eprom so that;s the issue here. Can yours?
-
Don't worry, it's not your fault, I've had it happen one or two times too, sometimes you cannot prevent it from happening because these things are 30 years old.
I actually did get one of those chips back working again with the method I mentioned. You just have to "fumble" a lot to get all the pins in the socket back in nice order including the "replacement leg".
-
I'll try to solder a new leg to it
-
My Old Friend teached me a trick for this, cut off a leg from a broken chip, put it to the socket first and insert the chip after that, now you will only have to drop a piece of solder between the 2 components. ;)
-
tx
well, the IC is socketed again, and I reseated all the eproms and CPU
result: it still doesn't work, but I see stuff moving now instead of a frozen screen
I see there is a kind of stripe on the PCB, I need to find out if the lines are cut, this is kind of a bummer.
I figured it would be working right away, another board will cost me about 150 euros or so
-
tx
well, the IC is socketed again, and I reseated all the eproms and CPU
result: it still doesn't work, but I see stuff moving now instead of a frozen screen
I see there is a kind of stripe on the PCB, I need to find out if the lines are cut, this is kind of a bummer.
I figured it would be working right away, another board will cost me about 150 euros or so
talk to jochen about it. i am sure he can fix the board.
-
I asked Robin, he lives very near to me, maybe he can help me. If not, I like every help I can get ofcoruse.
I checked the voltages on the ICs, those are 5,03V
I powered the DK a couple of times with these results
-
you can see its running, first pic you see the DK screen (messed up, but its there)
second is looks like the highscore screen (again messed up, but its there
and at last there is the barrel screen, also messed up, but its there
so the cpu is fine, its running and doing its job.
what about sound, is there anything ? and does it make sence with above explanation ?
i think you have some sort of rom / ram problem, because both character and sprite data are present, but totally screwed up
or something in the area that muxes the sprite and character data
i think Robin is your best bet at this stage, close to you and full of knowledge.
-
How the hell do you recognize those screens ?? :shock:
-
It's going to Robin
-
How the hell do you recognize those screens ?? :shock:
i need to admit that you have to be a little creative to "see" it..
I imagine the attract screen running, thats what happens when powering up the game.
from there , i know that the attract screen does the following ;
1. display "donkey kong" title screen
2. display highscore screen
3. display a demo from the barrelscreen
put this together with some of the characters and sprites that you see, and you have this :
parts of the sprites that are used to build the word Donkey kong :
(http://www.opdenkelder.com/pics/compare1.jpg)
very vague stretched repeated pattern of this :
(http://www.opdenkelder.com/pics/compare2.jpg)
And i see parts of the griders:
(http://www.opdenkelder.com/pics/compare3.jpg)
now, i am not 100% sure that this is it, but it sure looks close to it IMHO.
-
It froze alle times but one, maybe it actually IS the CPU. It's pretty frustrating not knowing anything about this
I can replace it for a known good, before bringing it to Robin
-
please do, and let me know, i am curious 8)
-
what do you want to know, if putting another Z80 will fix it?
-
replaced the Z80, same result
-
i am not surprised, it looks like the CPU is working.
if the CPU is not working, you will not have anything on the screen AFAIK
-
Been trying to call Robin whole week....did you contact him by phone ?
-
I don't have his phone nr. He said I can bring the pcb so thats great. Now I am waiting for him to give me his address
It will be ok. Just some patience.
-
He's the master.
The only thing I can figure out of those screen shots is that your monitor needs C407 replaced.
At least. :D
P.S. Etienne.......don't drink and visit the forum at the same time, your fantasy is running with you ;D ;D ;D ;D ;D
-
Yeah etienne will do the full cap kit
-
Lets see what Robin's opinion is, i am curious if my analytic skills are what i hope them to be ;D
-
it's going to Robin tonight so we'll soon find out.
he's kind of busy ATM, but he still wants to help me, that's really extar great :spaceace:
-
Your pcb is working again
-
That's really great news Robin.. tx so much
can you send me a PM with all info ($$, parts, tel nr)
:spaceace: :spaceace: :spaceace:
-
Awesome Robin, you did it again ;D
want to share the solution ?
-
A real magician never explains his tricks ;)
-
some EPROMs were broken, some in the wrong spot and the CPU didn't make very good contact with the board
-
some EPROMs were broken, some in the wrong spot and the CPU didn't make very good contact with the board
somebody tried reparing it before you ;D ;D