Robocop repair log #1

 PCB Repair Logs, Repair Logs  Comments Off on Robocop repair log #1
Jun 152011
 

Bought a Robocop board from the AO forums. Seller says the jump button didn’t work.
Doing a visual inspection revealed a burnt out track just off pin 23 on the edge connector, which is button 2, in this case, the jump button.

image

I repaired the trace but still no joy with getting the controls back.
Further inspection showed that the custom resistor array had burnt out. This resistor array has some modified characteristics compared a normal array, it passes an input out to a different pin and has a few other differences too. As I don’t have any spares of the custom array I decided to use a standard one pulled from a scrap board.

image

To make this work I had to short pins 6 and 7 together and 8 and 9 together. These are for button 1 and button 2.
The board is now fully working but ill keep an eye out for an original replacement part to fit.

Taito F3 region change

 General  Comments Off on Taito F3 region change
Jun 132011
 

I got a Puzzle Bobble cartridge today so I could test the F3 motherboard I got in the job lot a bit back.
The motherboard itself doesn’t do anything at all without a cartridge so I wasn’t sure if it worked or not.
The cartridge seemed to be a different region than my motherboard is but the lockout is a physical one rather than a software based one and requires cutting the posts out on the pin header sockets. With this done, the game fits and it booted up no problem.

Happy this thing works and Puzzle Bobble is really addictive.

More information on converting F3 games and boards can be found here

Commodore 64 loading devices

 General  Comments Off on Commodore 64 loading devices
May 292011
 

Ive recently got a couple of devices for loading games onto the Commodore 64.
The first is an SD2IEC which allows ROMs to be loaded from an SD card. This is a homemade version (thanks go to SirMorris) but works very well. If you install JiffyDOS then loading time is as fast as it gonna get on the 64. I loaded up Last Ninja 2 in about 4 seconds!


Second device is something called a Cassadapt. This allows me to load .WAV files straight into the C64 from a PC or other sound source.
Its not something many people would want as it brings back the long loading times that plagued the 64 but being a bit of a purist I happen to like some of the loading screens and music you get with some games, plus its that whole nostalgia thing too.
Its a very nice device which has the ability to copy .WAVs onto cassette using the original Commodore data cassette unit and vice versa. It even has a built in program that helps you calibrate the trigger level to obtain optimum sound levels.



I came across a small problem with JiffyDOS installed as it doesn’t support tape drives or similar, only disk based devices so I removed the 27c128 EPROM that JiffyDOS was on and fitted a 27c256 with both the C64 kernel and JiffyDOS programmed onto it and fitted a switch at the back to switch between the 2 as needed. Its a simple case of toggling pin 27 (A14) high an low to select kernels.

Commodore 64c repair log

 Computer Repair Logs, Repair Logs  Comments Off on Commodore 64c repair log
May 282011
 

The data cassette player would not power up and there was no sound outputted.
There is a big 1.5A fuse inside labelled F1. This supplies the +9v to pin 28 of the SID chip and is also used in powering the cassette unit.
Replacing this fuse brought everything back to life.

The C64c boots up fine without this fuse. I have been using an SD2IEC adapter to load games and didn’t realise at the time that the cassette unit was not working either.

Amiga Apollo 1230 expansion card repair log

 Computer Repair Logs, Repair Logs  Comments Off on Amiga Apollo 1230 expansion card repair log
May 272011
 

My good mate Andy over at RCM gave me his 1230 MK2 expansion card to have a look at last time I was there. The problem was the PLCC socket on the FPU was cracked at one corner.


I did manage to confirm this was the problem by holding the socket together so I ordered some socket from China and removed the old socket
The old one came off easy enough with a hot air gun.

The sockets came and I set about fitting it. I decided to use solder paste as it makes the job quite a bit easier when soldering surface mount things with many pins.
5 or so minutes later the new socket was on and after a quick check under the magnifying glass it was time for a test run.

Workbench reported the extra RAM and my 1200 was now a flying machine so im happy its working. Tried Scorched Tanks to make sure, its the only game that was on the compact flash drive!

 Older Entries  Newer Entries