A1200 Boot up issues

[sturulez]

Hi,

I turned on my Amiga 1200 yesterday and noticed something wasn't right. First thing i noticed is that when i turned it on the Amiga the power light came on but the HDD and FDD where not active, no ticking sound from the floppy drive so i thought I would change the power supply but that had no effect.

Secondly I opened up the Amiga, disconnected the accelerator and CF Card turned it on and nothing happened. I then removed the ROM 3.1 chips and replaced them with 3.0 ROM, turned on and nothing happened. I then put the 3.1 ROM's back in and the Amiga came back to life.

I noticed after I rebooted the machine a few times a green light appeared on the screen, but not every time, am I right in believing this might be a RAM issue?

[sturulez]

How easy is this to fix?

[sturulez]

I've never tried flashing ROM chips or used Diagrom before


 

[sturulez]

No this Amiga hasn't been recapped. I purchased it from Amiga kit about 10 years ago.

Okay so this evening I took the amiga apart. I am yet to clean the chips and remove them from the sockets.

I did replace the 3.1 ROM chips with 3.0. Couldn't see an issue. I then thought I would use the 3.1 chips again. everything booted up okay into workbench. I left the amiga for about 10 minutes and when i came back the screen was green. I then turned the amiga off, back on again and the screen was dark grey with black vertical lines. No sound was coming from the floppy drive and the hard drive wasn't doing anything.
Performed a Ctrl + A + A and rebooted it, the screen flashed up purple for a few seconds and then went back to black again.

Could my 3.1 ROM chips be faulty?

[sturulez]

If my ROM chips are not at fault would a recap resolve the issue?

[sturulez]

Okay this evening I removed the motherboard from the outer casing. Luckily I have a spare Amiga 1200 so I’ve managed to test the ROM’s on that machine and they work fine.

The faulty board is a Rev 1A and the working board in a Rev 2B

Upon inspection of the faulty motherboard I noticed round circular component near to where the PSU plugs in looks like something might of leaked out of it. See the attached photo

When the 3.1 ROM’s and floppy drive are plugged into the faulty board nothing happens when power it up, Just presented with a blank screen now.

Am I right in believing a recap for this would possibly resolve the issue?

[sturulez]

Please see attached image

[sturulez]

I have a feeling it might be the tracks under the ROM, they have had various ROM's in there over the last few days. 

Certainly not the easiest chip to get out if you have taken the heat shield off.

Hi!

A recap won't fix the issue unless there has been major leakage but does not really affect the A1200 in this way. It maybe Gayle or simply clean up the expansion connector. Careful removing ROMS as you could damage the tracks under the ROM.

Good luck!

Steve

Not sure about that but every Amiga should be recapped, especially smd models like 600/1200.
My 1200 had floppy issues, it was caused by this.

[sturulez]

Many Thanks to Amigakit for sorting out my A1200.

All working now 

[sturulez]

Power caps leakage, full recap and replaced 4 x RAM chips