Amiga 500+ repair... battery leakage

[roMancer]

hi,

it's my first a500-repair job, this is how it was when i got the amiga500+ and what I did so far:
just quickly boots over and over again.
battery leakage, some parts do not look too good, some traces on the pcb damaged.
did some soldering adding wires, with some success (yellow screen, green screen, red screen).
did more soldering adding wires, more success :-)
now it sometimes shows the bootscreen (rom2.04 insert disk animation)

but it's very unstable, this is the situation now:
- sometimes the amiga shows the bootscreen, then after some amount of time (varies from seconds to minutes) -> powerLED flicker, reboot, software failure guru screen
- sometimes it doesnt, screen colors go from black to grey -> powerLED flicker, reboot
- sometimes it doesnt, screen colors go from black to grey to light grey -> powerLED flicker, reboot
- sometimes it doesnt, screen colors go from black to grey to light grey to white -> powerLED flicker, reboot
(the latter three may rarely show a software failure guru screen, too)

I have to add that U12 got fried pretty good by my soldering "skills", just in case that might be relevant.

does that sound familiar to anyone?
any suggestions what to look for or to check next?

thanks!
regards,
ro

[pyrre]

Been working on my A500+ as well.
Luckily it was not damaged from the battery, i got the battery removed before it could do serious damage. But the a501 trapdoor ram is damaged beyond repair.

Now i continue working on the 500+. Trying to solder the derringer to the board, at an angle.....(!) to get it under the keyboard, bot above the indievision.
Still a work in progress.
And i am hoping to find any clues to how to add another 1MB of ram.
The motherboard already has one. after that i am going to attempt making the 128 MB ram mod to the derringer. Just got to get my hands on a 128MB module first.

And if possible. find a hdd controller to place on the cpu socket (under the derrigner) that will work with the derringer.
In the trumphcard i only have an old SCSI controller with a faulty disk. Bad sectors. and i have no clue to how to exclude them from the drive.

Anyways....
Try retrogamemods channel on youtube. great inspiration from him. Trying to find a way to contact him about modding the ram on the motherboard of the 500+
Oh.. and vinegar worked nice to neutralize the corrosion from the battery.
But look at his videos.

[Oldsmobile_Mike]

Soldered to the board?!  My VXL*30 fits underneath the keyboard and above both an Indivision and a Megachip, using only one additional spacer on the CPU socket. But good luck with that!

[Motormouth]

hi,

it's my first a500-repair job, this is how it was when i got the amiga500+ and what I did so far:
just quickly boots over and over again.
battery leakage, some parts do not look too good, some traces on the pcb damaged.
did some soldering adding wires, with some success (yellow screen, green screen, red screen).
did more soldering adding wires, more success :-)
now it sometimes shows the bootscreen (rom2.04 insert disk animation)

but it's very unstable, this is the situation now:
- sometimes the amiga shows the bootscreen, then after some amount of time (varies from seconds to minutes) -> powerLED flicker, reboot, software failure guru screen
- sometimes it doesnt, screen colors go from black to grey -> powerLED flicker, reboot
- sometimes it doesnt, screen colors go from black to grey to light grey -> powerLED flicker, reboot
- sometimes it doesnt, screen colors go from black to grey to light grey to white -> powerLED flicker, reboot
(the latter three may rarely show a software failure guru screen, too)

I have to add that U12 got fried pretty good by my soldering "skills", just in case that might be relevant.

does that sound familiar to anyone?
any suggestions what to look for or to check next?

thanks!
regards,
ro

The errors you are getting make sense.  The battery is near the gary chip and the traces going to the chip ram.  Also it is near the audio filter, which also effect the power LED

I would get the A500+ wiring diagram, it sounds like you "may" be missing some of the chip ram signal lines.

Have you every been able to boot far enough to fine out if your audio works?  Does your amiga have audio???

[pyrre]

Soldered to the board?!  My VXL*30 fits underneath the keyboard and above both an Indivision and a Megachip, using only one additional spacer on the CPU socket. But good luck with that!

With an additional socket the derringer squeezes so tight at the indievision that a simple bodge to the case and it pops off....
And it collides with the keyboard. somewhat two - three millimeters before the keyboard hits the post it is supposed to rest at...
Don't dare to run the computer that way