Bought a non working Jaleco Astyanax pcb for a good price. Already had a perfectly working set so I felt this could be quite useful in fixing the broken one.
Seller said it didn't power up, so after powering it up, I just confirmed it- blank screen. What I like to do first is a good visual inspection of the pcb, front to back, top to bottom, looking for broken pins, broken traces, lifted SMD pins and such. It looked pretty good to me visually. I also like to power the pcb up and run my hand lightly over the chips to see if any get hotter than the average chip would. Upon running my fingers over a couple of the ram chips, I noticed right away these (2) chips were HOT.
Becaue I don't have an eprom writer that tests these ram chips( as far as I know), I decided I would grab the trusty Hakko desoldering gun and take these (2) chip out. As hot as they were, I knew they were toast, literally.
After pulling them and getting some help with replacements, thanks @ShootTheCore , they were socketed and installed.
Next I started pulling and testing the mask roms from the romboard. On my romboard, (7) are socketed, and (5) as soldered right to the pcb, aaargh. So out of the (7) socketed, (5) of them tested bad when compared to the Mame rom set. So, I figured I would test what was easy and see where I stood. I used my Needhams EMP-21 to burn some fresh eproms to replace those bad maskroms.
Now to test, fingers crossed:
OK, it's progress anyway! Backgrounds, etc were obviously messed up. I was hoping I wouldn't have to deal with those (5) mask roms soldered to the board, but looks as if they would have to be dealt with. So, I desoldered them and placed sockets on the board.
Here's where it got confusing for me. All of the rom sites I frequent. and ones I don't only contained Astyanax romsets that contained (23) roms, in which none of them were of 512KB which were what these (5) were- 27C4001 maskroms on my pcb. I found this surprising seeing out of all the Atsyanax pcb's I have seen, almost all of them looked like mine, and not a fully maskrom populated romboard. I really had to search to find one that was fully populated. I just knew there was altleast one, maybe more of these maskroms that were going to be bad on this romboard. After asking around to some fellow collectors, I just finally came down to the conclusion that I was just going to go to my fully working Astyanax pcb, desolder the known good maskroms I needed and get the files from those chips. So, after desoldering and putting sockets on my working rom pcb, I read out all (5) maskroms and burned the files to some fresh eproms for the non-working pcb. Once everything was put back together, this is what is what I was presented with:
Beautiful! A great feeling to take something from a broken state and make working again. Sure, this was just an easy one for the experts, but goes to show that just an average guy like myself can get a victory too. Not sure if any Mame people would be interested, but these (5) roms I pulled from the soldered maskroms may be useful. Like I said, I could not find these roms anywhere. Would have saved me quite a bit of work, not to mention technically altering an original pcb by putting in sockets on my working pcb, etc. Thaks, hope this can help someone out-
Seller said it didn't power up, so after powering it up, I just confirmed it- blank screen. What I like to do first is a good visual inspection of the pcb, front to back, top to bottom, looking for broken pins, broken traces, lifted SMD pins and such. It looked pretty good to me visually. I also like to power the pcb up and run my hand lightly over the chips to see if any get hotter than the average chip would. Upon running my fingers over a couple of the ram chips, I noticed right away these (2) chips were HOT.
Becaue I don't have an eprom writer that tests these ram chips( as far as I know), I decided I would grab the trusty Hakko desoldering gun and take these (2) chip out. As hot as they were, I knew they were toast, literally.
After pulling them and getting some help with replacements, thanks @ShootTheCore , they were socketed and installed.
Next I started pulling and testing the mask roms from the romboard. On my romboard, (7) are socketed, and (5) as soldered right to the pcb, aaargh. So out of the (7) socketed, (5) of them tested bad when compared to the Mame rom set. So, I figured I would test what was easy and see where I stood. I used my Needhams EMP-21 to burn some fresh eproms to replace those bad maskroms.
Now to test, fingers crossed:
OK, it's progress anyway! Backgrounds, etc were obviously messed up. I was hoping I wouldn't have to deal with those (5) mask roms soldered to the board, but looks as if they would have to be dealt with. So, I desoldered them and placed sockets on the board.
Here's where it got confusing for me. All of the rom sites I frequent. and ones I don't only contained Astyanax romsets that contained (23) roms, in which none of them were of 512KB which were what these (5) were- 27C4001 maskroms on my pcb. I found this surprising seeing out of all the Atsyanax pcb's I have seen, almost all of them looked like mine, and not a fully maskrom populated romboard. I really had to search to find one that was fully populated. I just knew there was altleast one, maybe more of these maskroms that were going to be bad on this romboard. After asking around to some fellow collectors, I just finally came down to the conclusion that I was just going to go to my fully working Astyanax pcb, desolder the known good maskroms I needed and get the files from those chips. So, after desoldering and putting sockets on my working rom pcb, I read out all (5) maskroms and burned the files to some fresh eproms for the non-working pcb. Once everything was put back together, this is what is what I was presented with:
Beautiful! A great feeling to take something from a broken state and make working again. Sure, this was just an easy one for the experts, but goes to show that just an average guy like myself can get a victory too. Not sure if any Mame people would be interested, but these (5) roms I pulled from the soldered maskroms may be useful. Like I said, I could not find these roms anywhere. Would have saved me quite a bit of work, not to mention technically altering an original pcb by putting in sockets on my working pcb, etc. Thaks, hope this can help someone out-
