The A500 is still throwing yellow screens at startup and the parts are lost in USPS limbo (Apparently they had a vacation in Chicago for 10 days and are now 5 days into a roundtrip) In the meantime the RAM expansion can be dealt with and I suppose I could refurb the floppy drive. What would you like to see?
Thanks, maybe we need to get together and come up with a middle ground process. Most of these are taking way too long to produce. 2 weeks into the bench power supply right now although it was interrupted by our annual canning fest
I like to use super capacitors in coin battery holder form factor. They don't leak, should last for ever and take charge from the original charging circuit, or you can hack one together with a resistor and a zener if there's no charging circuitry in the original. They will keep the clock running long enough if you use the machine somewhat frequently. And if you don't use the system for a long time.. it stays ready to serve :-)
Ben, That's a good point and one I had not considered for this project. I used a 1 Farad cap for the settings battery on my Bally pinball machine and it does work as long as it gets powered up at least once a month. Since its not used once a month anymore it can be funny the random settings that come up when its started. Have you had issues with the clock chip getting into an invalid state? I understand that's a risk every time the battery dies, coin cell or not.
The battery is just to keep the Realtime clock running while the computer is off. The RAM expansion is unaffected if it is missing. The clock will work as well, you just have to set it manually each time you power cycle the machine
Thanks. I asked because I just removed the leaked battery of my ram expansion of my amiga500 by cutting the metal-holders.. For some reasons games like turrican did not start with it... after I remove the expansion the game will load... So I guessed they may could have some routines requiring a working real-time-clock of the expansion... when expansion is available
I doubt its a cap but anything is possible. My A500 is still a bit buggy so I am planning to dig into it soon. It seems like they have a lot of issues with bad sockets.
Good question. I was concerned that the proximity of the caps to the leaking battery could have compromised them so I went ahead and replaced the electrolytics just to be safe.
Well, recently found my A500 in a dead state. :( Pulling out the A501 RAM expansion module DID bring it back to life, so I suspected a battery leak. Sure enough, it leaked indeed, but cleaning it with rubbing alcohol did little good (at one point it booted but wouldn't detect the extra 512K, and created significant instability). Right now booting the Amiga cycles through colored screens but never gets to the white screen--that appears before the Kickstart ROM version shows up. So the RAM module is unusable. The battery still holds ~1.5v, but I suspect I'll have to remove it and figure out what else has gone bad....DRAMs? capacitors? resistors? I may have a spare A501 module in storage, but it likely will have the same leakage issue (ditto for my A2000, need to check that!)
@@RavenWolfRetroTech - Any idea what component on the A501 is causing the Amiga to halt its start up process? I looked with a magnify glass and didn't see any advisably damaged components or traces where the battery leaked. It's populated with "MT" brand DRAMs, which I vaguely remember people in the Apple II/C64 community saying are prone to failure (they have a strange part number, but I take it they're just 256Kx1's?). It worked last time I used the machine, it just sat on the shelf a few years, battery leaked and now the A501 is preventing it from booting up. :/
Its hard to say, this video is of the only A501 I have restored but you are very right to suspect MT RAM, the stuff is garbage. You can try piggybacking but that only tests for certain failure modes. You can also see if any of them get hotter than the rest if you can get to them while the machine is running.
The A500 is still throwing yellow screens at startup and the parts are lost in USPS limbo (Apparently they had a vacation in Chicago for 10 days and are now 5 days into a roundtrip) In the meantime the RAM expansion can be dealt with and I suppose I could refurb the floppy drive. What would you like to see?
Enjoying this and your last Amiga video. Thanks for sharing your retro fun!
Thanks Matt, I'm glad you enjoyed them!
Great video. I have an Amiga 500 coming soon to me. I think adding a Ram expansion will make a great project for me.
That sounds great Tron, are you thinking of finding an older one to restore or are you going to make a new one from the plans online?
@@RavenWolfRetroTech I'd like to get an original one if possible.
Great video! Thanks! My channel lives up to my opener after watching yours. You do good work. Mine…..yeah.
Thanks, maybe we need to get together and come up with a middle ground process. Most of these are taking way too long to produce. 2 weeks into the bench power supply right now although it was interrupted by our annual canning fest
I like to use super capacitors in coin battery holder form factor. They don't leak, should last for ever and take charge from the original charging circuit, or you can hack one together with a resistor and a zener if there's no charging circuitry in the original. They will keep the clock running long enough if you use the machine somewhat frequently. And if you don't use the system for a long time.. it stays ready to serve :-)
Ben, That's a good point and one I had not considered for this project. I used a 1 Farad cap for the settings battery on my Bally pinball machine and it does work as long as it gets powered up at least once a month. Since its not used once a month anymore it can be funny the random settings that come up when its started. Have you had issues with the clock chip getting into an invalid state? I understand that's a risk every time the battery dies, coin cell or not.
Can anyone tell if the battery is necessary for the expansion to run correctly (games) ?
The battery is just to keep the Realtime clock running while the computer is off. The RAM expansion is unaffected if it is missing. The clock will work as well, you just have to set it manually each time you power cycle the machine
Thanks. I asked because I just removed the leaked battery of my ram expansion of my amiga500 by cutting the metal-holders..
For some reasons games like turrican did not start with it... after I remove the expansion the game will load...
So I guessed they may could have some routines requiring a working real-time-clock of the expansion... when expansion is available
I don't know why.. but today Turrican worked with the Ram-Extenstion..
Maybe there's just a problem with a faulty capacitor ...
I doubt its a cap but anything is possible. My A500 is still a bit buggy so I am planning to dig into it soon. It seems like they have a lot of issues with bad sockets.
Is there a reason why you replaced the caps ? I just tested mine on my rev 5 A501, all within tolerance and ESR is normal so I just kept them.
Good question. I was concerned that the proximity of the caps to the leaking battery could have compromised them so I went ahead and replaced the electrolytics just to be safe.
Well, recently found my A500 in a dead state. :( Pulling out the A501 RAM expansion module DID bring it back to life, so I suspected a battery leak. Sure enough, it leaked indeed, but cleaning it with rubbing alcohol did little good (at one point it booted but wouldn't detect the extra 512K, and created significant instability). Right now booting the Amiga cycles through colored screens but never gets to the white screen--that appears before the Kickstart ROM version shows up. So the RAM module is unusable. The battery still holds ~1.5v, but I suspect I'll have to remove it and figure out what else has gone bad....DRAMs? capacitors? resistors? I may have a spare A501 module in storage, but it likely will have the same leakage issue (ditto for my A2000, need to check that!)
I would start by removing the batteries from all of them to prevent further damage... good luck, it sounds like a nice stable of machines
@@RavenWolfRetroTech - Any idea what component on the A501 is causing the Amiga to halt its start up process? I looked with a magnify glass and didn't see any advisably damaged components or traces where the battery leaked. It's populated with "MT" brand DRAMs, which I vaguely remember people in the Apple II/C64 community saying are prone to failure (they have a strange part number, but I take it they're just 256Kx1's?). It worked last time I used the machine, it just sat on the shelf a few years, battery leaked and now the A501 is preventing it from booting up. :/
Its hard to say, this video is of the only A501 I have restored but you are very right to suspect MT RAM, the stuff is garbage. You can try piggybacking but that only tests for certain failure modes. You can also see if any of them get hotter than the rest if you can get to them while the machine is running.