The Simpsons PAL dumps added

 PAL Updates  Comments Off on The Simpsons PAL dumps added
Aug 312014
 

I have dumped the two PAL16L8’s from The Simpsons PCB.
The PCB is a non worker right now so I cannot test them so if anyone out there in internet land can test these I would be grateful.

 Posted by at 4:13 pm

Star Jacker repair log

 PCB Repair Logs, Repair Logs  2 Responses »
Aug 302014
 

Got a mammoth box of boards from Ben76 the other day. This Star Jacker PCB is one of them.
Game gave a black screen when powered up and there was no sync signal.
Ben also gave me a scan of the schematics for this board so was quickly able to determine where the sync came from.
My heart sank a little bit as the sync comes from a PAL16R4 chip
sj-sync

On investigating I found the VCC pin was not making a good contact in the socket so I removed both of the PAL sockets and replaced them.
IMAG0839

So booting now gave me sync but solid white screen. Ive seen this before on quite a few boards and its almost been RAM issues. I started probing the RAM chips and found a 2016 SRAM at location IC151 had completely dead outputs despite being enabled and having active inputs. I desoldered it and replaced it with a 6116 SRAM chip.
IMAG0840

Now I get this (NOTE: the red colour is actually present but I have to edit my pictures these days as the HTC One makes low light pictures all purple)
IMAG0842

IMAG0843

All fully working again.

Under Fire PAL dumps added

 PAL Updates  Comments Off on Under Fire PAL dumps added
Aug 292014
 

Bad_ad84 has sent in some dumps from an Under Fire PCB.
They are untested right now and are still in PAL format.
At present ive left them all in a single ZIP file until we can check them out to see if at least the equations look plausable as its always possible some of the devices were locked.

Thanks to Bad_ad84 for his contributions, much appreciated.

 Posted by at 9:05 pm

Jigoku Meguri (Bonze Adventure) repair log #1

 PCB Repair Logs, Repair Logs  Comments Off on Jigoku Meguri (Bonze Adventure) repair log #1
Aug 282014
 

I got this Bonze Adventure (actually, it ended to be Jigoku Meguri, the japanese version) PCB as gift from my friend Silvio:

Bonze_Adventure_PCB

 

Board was in decent state but it was missing the YM3016F DAC and the TC0100SCN tilemap generator :

missing_IC

so I used a Drift Out faulty PCB as donor for these two ICs.

Besides, some pads of the TC0100SCN ASIC were missing and the RGB module TC0070RGB fell off in my hands once I touched it.I rebuilt missing pads using some AWG30 wire and I exposed the TC0070RGB pins using my Dremel in order to  solder new legs:

TC0100SCN_rebuilding

TC0070RGB_rebuilt

 

RGB module doesn’t use a standard 2.54mm pitch but 1.77mm so I used an half of a 64 pin S-DIP socket for its installation on PCB:

TC0070RGB_installation

 

All was set and ready for powering on the PCB.Once done, I got a solid black screen but all activity on 68000 adreess/data bus seemed fine.So I’ve started to think about a video RAM failure and I piggybacked a 62256 RAM over the one @IC4 which had some data lines stuck HIGH, this was the result:

Bonze_error

 

so I desoldered it and tested out of circuit resulting as showed:

62256_failure

 

 

But, though I replaced this RAM, I got the same error.So I remembered that my friend Silvio told me a lot of Bonze Adventure had both the tile RAMs bad so I decided to desolder also the other one 62256 RAM @IC5 and he was right, it  was really bad!

Fitted another good one and  :

Bonze_Adventure_fixed

 

I could enjoy this weird game!Thank you again , Silvio, for donating me this PCB and  for your precious advices! 🙂

 

 

 Posted by at 10:06 am
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