amiga 500 plus (dead?)

[skywalkgr]

Hello to everyone

I bought an amiga 500 plus computer from ebay/DE. The problem with this is when i power it on the green led (power) is blinking and i get a green screen on my tv.

I opened it and i removed the battery, it looks that there is no leak from battery but i am not an expert. The board is revision 8A (b52/rock lobster) with kickstart 2.04. I used also a tool and i removed fat agnus and i put it back again but with no luck.

Is there a person that he can help me with this? I can send the machine worldwide i dont care about the cost, i would like that it will be fixed

Thank you

[skywalkgr]

I believe green screen is an indication of bad ram. Do you have a ram board in the underside (trapdoor) expansion? I've gotten a few 500's with good onboard ram but the expansion ram was bad somehow. If there is a ram expansion board in the underside port, remove it and see if it will boot.

Steven

Thanks for mention it, no i dont have something plugged in the underside (trapdoor).
I took  the expansion card (512k) from my other amiga 500 and put it to amiga 500+ with no luck :/

[skywalkgr]

If that doesn't fix it, it's probably a bad RAM chip.
There are people closer than myself but I could probably fix it if you really need to. I'm in the UK though, so postage would be expensive.

YES?? This would be great!!
I can send the mainboard to UK and i am willing to pay for the service Can we arrange it?

[skywalkgr]

Give still a wiggle/push to every socketed chip. And look at the Agnus socket if it's not cracked; you could gently scrape the Agnus contacts to be sure that they pass the voltage thru. I had a 500 that gave green screen because of defective Agnus contact.

I pulled out fat agnus with tool extractor and i check the socket and it looks in great shape. When you say "you could gently scrape the agnus contacts to be sure that they pass the voltage thru" what do you mean? How i will do this? is there a possibility that i can harm the chip?

[skywalkgr]

Yes thats another thing that sometimes works, push down hard on every socketed chip. Clean the motherboard, disconnect and reconnect everything tightly and try to boot it again...

Steven

When you say push hard -- how hard is hard?? I hope i will not break something...
Everything seems to be in place except kickstart chip (close to agnus). i dont know if its normal but there is space between chip and the socket so i can see  through the other side of the chip.

[skywalkgr]

Close to the battery (on the left) there is one chip, the pins on this chip seems to be green , maybe its fluid from battery i dont know. Does anyone know what kind of chip this is?

[skywalkgr]

Can you send us a close-up photo of the area? It shouldn't be green....

Here is the close-up photo, its not my mainboard. Its a picture from an amiga hardware site. I am at work now so its difficult to make a photo of the board

[skywalkgr]

SN74LS244N - LOGIC, BUFF/DVR TRI-ST OCTAL driver chip.

i have a question , under SN74LS244N there is also a second code "FFCZ9133" i searched on ebay and i found some SN74LS244N from Texas instruments and also a few motorola. But the second code is not the same :/

Where i can find this chip?

[skywalkgr]

A photo of your particular motherboard was what I meant.

I've got several LS244s here... they cost about £1 on eBay. But yes, do check for traces and things like that - it could be something really simple that's gone wrong!

Is it possible to use this chip that you have to my amiga 500+? Do i have to flash them or do something before i use them?

[skywalkgr]

Nope, the LS244 is a bog standard logic series chip. But to be honest it's probably not at fault, even if the legs are a bit green. The green will come from corrosion from the battery, yes, but chances are it's just on the surface. What you need to look out for is corrosion around the base of the chip - check the tracks around it. Any chance of a photo of your board around the 244?

i will check the mainboard today, sorry i didnt have time yesterday to upload photo. I will do it today

[skywalkgr]

Nope, the LS244 is a bog standard logic series chip. But to be honest it's probably not at fault, even if the legs are a bit green. The green will come from corrosion from the battery, yes, but chances are it's just on the surface. What you need to look out for is corrosion around the base of the chip - check the tracks around it. Any chance of a photo of your board around the 244?

i will check the mainboard today, sorry i didnt have time yesterday to upload photo yesterday. I will do it today

[skywalkgr]

Here are some photos of my board, i hope that they will be helpful

[skywalkgr]

Have you checked all the traces around the battery thoroughly? especially the one that comes down between R11 and E10.

With naked eye i can see that something is wrong there, but i am not an expert I will check the lines today with magnify glass. You think that if its something wrong it can be fixed easily? i hope for a yes!