Thanks man I'll let you know. I think A and B are good. I bought a busted multi for "fun" and slowly trying to revive it.If its A and/or B board issue let me know. I have spares so can send a set your way to test on, just pay shipping
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Johnfan1986
Professional
I had the same issue before. I removed and plugged the F pal and soldered the tin again on F pal leg and pin on multi. The bar and line fixed. Maybe you can try it.Oooo, some progress! I reflowed U34 pins 8,9, and 10 and graphics improved significantly. I still got jail bars and lines over some sprites and text, but I can actually make out what's on the screen now.
Thanks @Johnfan1986. I tried disconnected and booting, no change. Re-soldered both ends and same issue.
Johnfan1986
Professional
O... You use G pal? (If not, Maybe try to change it as g pal).
I checked the instruction manual. It mentions:
1. Kit has broken pins. (Need check up)
2. B board has damage sockets. (?)
3. Kit is not good contact. (?)
4. A & B board are not making good contact. (May not be yr situation, however press the A&B board hard again)
Hope it can help to fix the jailbars
I checked the instruction manual. It mentions:
1. Kit has broken pins. (Need check up)
2. B board has damage sockets. (?)
3. Kit is not good contact. (?)
4. A & B board are not making good contact. (May not be yr situation, however press the A&B board hard again)
Hope it can help to fix the jailbars
I have F PAL with pin 7 soldered to multi J17. If I disconnect J17 from the PAL there is no change in graphics or functionality that I can tell. I don't think I have any broken pins, I've tested 2 different known working A boards.
Had enough for the night. Here are some other things I uncovered:
U53 pin 8 stuck low, pin 16 floating unless sprites on screen. Replaced, same issue.
U52 pin 8 and 16 stuck low
U51 pin 15 stuck low, pin 10 stuck high unless sprites on screen, 9 stuck low unless sprites on screen, 8 stuck high unless sprites on screen
Edit: Fixed typo, PAL wire is on pin 7, not 9.
Had enough for the night. Here are some other things I uncovered:
U53 pin 8 stuck low, pin 16 floating unless sprites on screen. Replaced, same issue.
U52 pin 8 and 16 stuck low
U51 pin 15 stuck low, pin 10 stuck high unless sprites on screen, 9 stuck low unless sprites on screen, 8 stuck high unless sprites on screen
Edit: Fixed typo, PAL wire is on pin 7, not 9.
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U51, U52 and U53 are level shifters. They translate the data from pins 14-21 towards 3-10. The pin that chooses direction is pin# 2 and it's connected to GND, so direction is always B->A.
All these pins that you mentioned are data, so they should be all floating....The level of activity in pin 21 (input) should be the same as in pin 3 output, the same for pin 20 and 4, etc. so if you see differences there, that probably means a bad level shifter.
All these pins that you mentioned are data, so they should be all floating....The level of activity in pin 21 (input) should be the same as in pin 3 output, the same for pin 20 and 4, etc. so if you see differences there, that probably means a bad level shifter.
This is good to know. I did quickly check the datasheet for the pin out, but didn't realize the pin relationship. I'll go back and probe these again.
First time really using the logic probe, still learning. When I said floating I meant there was no signal on the probe. Hopefully I'm using the right term here.
First time really using the logic probe, still learning. When I said floating I meant there was no signal on the probe. Hopefully I'm using the right term here.
I think the level shifters check out ok. My only known issue at the moment is not being at to successfully flash U83 (Flash 12) with the 10101010 test rom set. I just swapped the flash chip out for a second time and still the same issue. It flashes with 01010101 ok.
