Amiga 500 no display no boot

[the_bandit]

Hi, just wondering if anyone can give me a clue as to what I'm forgetting or what the fault might be. I moved interstate 3 years ago and left 2x Amiga 500 at my in-laws in their shed. I just got my hands on them now and set them both up and cant get the Workbench screen to come up on either machine (worked fine prior to storage). They both power up (red power light) and caps light come on but no floppy will boot when inserted. So far this is what I have tried with both units, connected to original crt monitor (blank screen) connected to lcd T.V via A520 adapter and it just sits on a blank blue av screen. tried both power supplies on each machine and nothing, the last thing I have tried is cleaning and inspecting all hardware and chip's (boards are clean no corrosion or oxidising). I removed the Cpu, Rom, Paula, Gary, Denise, and even reversed the cia chips and no luck (haven't tried Fat Agnus). The only problem I found was the battery leaked on both the expansion 512k cards, they didn't seem to do any damage to the cards as it was minor leakage. I'm assuming it should still boot up on the main 512k on board chip memory with the expansion memory removed (any thoughts on this).
I'm at a loss with this issue as I cant understand why both machines have identical faults, I cant even get one machine working out of the two. Any help would be great before I buy a third machine and use these two for parts.

[ElPolloDiabl]

Tell us exactly wha the lights are doing at power on. Is the floppy light coming on at all?
You can rule out the power supply as the problem. Are the floppy drives clean?
Did you do a 1MB chip ram hack while you had the 512k cards?

What happens at power on with the 512k card installed?

[the_bandit]

power lights seem normal, bright red, the floppy light does nothing unless you take the Gary chip out then it lights up green so that seems normal. there are no memory hacks as I have had these machines since new from a kid. I have given the floppies a clean out from any dust with caned air, not sure how to clean the head on it I haven't looked into that yet but I wouldn't think a dusty floppy drive would not give a display on the screen. With the 512k memory installed in the trap door it does exactly the same as it would with out the card. I'm leaning towards more of a cpu problem with the blank black screen as described in the fault codes (I have swapped both machines cpu's over and still nothing, but they both have the same fault so cant be sure if this test is accurate). I get no greys or whites not even a flick of the screen at power up to indicate self testing, its weird there both doing the same thing yet never had a problem since I have owned them.

[ElPolloDiabl]

I googled a bit and found out this problem can occur from:
a: Agnus is not seated correctly
b: the chip RAM has been damaged

Also one person had a faulty A520 modulator. Make sure you test with your CRT first.

[spirantho]

If you don't get a gronking floppy drive, then it's not booted (so the A520 is out of suspicion).

A black screen in my experience is caused by a bad track between the CPU and the Kickstart ROM, or bad capacitors preventing it from reaching a clean 5V supply. If there's no corrosion at all, then I'd guess the caps.

[the_bandit]

the only thing I haven't pulled out and re-seated is the Agnus chip so you may be right however I don't have a tool to remove it, any tips how to get it out with out damaging anything?
I'm sure the A520 is fine I have tried the crt monitor via rgb 23 pin socket so unless the socket is faulty the adapter and monitor should be o.k
 
one machine makes the gronking floppy sound the other one not so much but one is a rev5 the other is a rev6a which have different floppy's (cant remember how they gronked when they worked)
I'm on they same suspicion that it may be cpu or rom related, the boards seem O.K. but I might take another good look at it again. All chips legs are clean and shinny now but were a little cloudy when removed, I tried getting into the sockets on the mainboard but they still looked cloudy as I couldn't get in-between the plastic moulded socket. Does anyone know how to clean the sockets with out damaging any of the hardware, I have read that some electronics spray work to get rid of dirt and grime but is there something out there that might get rid of any oxidisation that might not be visible. I did a bit of reading that white vinegar removes oxidisation and battery leaks from electronics but one needs to be careful its not left on there to long. any thoughts

[Oldsmobile_Mike]

Electrical contact cleaner?

Also try just pressing down on the Agnus chips first, although if you really want to remove them you can pull the motherboard and press them up from underneath (carefully!).

There's an old story that Commodore techs used to just drop the machines from an inch or two up to reseat the Agnus's,  because a speed bump at the plant would knock every one loose on its way out.  

[the_bandit]

I think I'm at a loss, I had another go at it today and removed the angus chip (gave it a clean) and no luck. the boards look very clean no indication of anything wrong with a visual inspection. I think I'm going to have to use them as parts machines. I just purchased another A500 with a GVP II and some other upgraded goodies that I'm told is in working condition. The other two were part of my child hood and have sentimental memories, but I need to keep the memories alive "AMIGA FOREVER".
 
if anyone still has any ideas or feed back please let me know I would still love to get at least one of them or maybe both working

[Oldsmobile_Mike]

Agreed, definitely leaning toward the chip ram or the caps, but since you've got another one coming save them for parts at least!  Oh, and you'll love the GVP controller, I just posted a link to where you can get 8 MB of memory for it for $11 with free shipping, off ebay, over in the marketplace forum.  Lots of cheap upgrades you can do on an A500: throw in a 68010, ECS chipset, 3.1 rom, do the 1MB chip ram hack, all for under $20 each.  Love 'em!  You'll be able to use WHDload to get just about any old game you can think of running on this kind of machine, just watch out you don't start staying up till 5am messing with it, like I do mine.  

And also I recommend checking out the Indivision ECS, it's about $100 from AmigaKit but will allow you to use any modern LCD monitor or TV for your display, and adds a bunch of new high res graphics modes.  Have fun!  

[the_bandit]

I have been wanting a GVP for a while, I hate it when your favourite game gets corrupted and having to swap the disks back and forth. I have read heaps about all the cool things that can be done with these old machines. I could never imagine being able to do all this stuff before in the day with out eBay & Google.
I'm not 100% sure what's in the machine I bought, hoping it already has the 8mb if not that's easy to sort out.
I also have 2 old Seagate 2gb Barracuda SCSI drives in the garage that I'm sure should fit so I will refit and re-load workbench (can you double up drives in the GVP with master/slave settings or not, never worked with one of these before)
I was also told it has a ADSpeed card on the cpu but I believe its the one with out the ide port. not sure when I will get my hands on it my brother picked it up today from the seller and has it his house (2hour drive to get it).

[the_bandit]

PROBLEM FIXED!!
anyone having the same issues change the kick rom chip.
I just got my 3rd Amiga and I nearly cried no display again, this time I had no red power light and a solid green floppy light so I just pushed the Gary chip back in and thank good I got V1.3 boot up floppy hand on screen. so now I had the thing opened I thought I would take out my 2.04 kick rom from the other machine and stuck it in and what do you know I got no display on my new machine. Put the 1.3 rom in my original Amiga and it booted up. I haven't tried the 3rd machine yet but I cant be bothered to have 3 machines in pieces. I'm going to order two more kick roms and see if I can get them all up running. any suggestions should I get v3.1 roms or stick with the 2.x versions.
just also which mother board would be better to use out of the two rev 6A
 /87/88 with moss chips or /89/90 CSG chips
 
Thanks for all the help guys I hope this might help someone else out there with the same problem