Coleco Adam Black Screen Hum

[INTVCruise]

Hello everyone, just got an extra adam console portion only, no drives in it or anything, and when I power it on the screen is just black and a loud hum, sometimes no hum. Power supply was tested and works on my functioning adam. I tried a working cassette drive in the broken adam and it spins if you hold the center plunger in with a tape, but resetting doesn't get the tape or spin normally. Keyboard plugged in does get a red light, but typing does not get the printer to print any characters. Resetting the ColecoVision portion also does nothing, except that it makes the hum go away sometimes as well, inserting a cartridge doesn't bring up the game nor does having nothing in the slot. Tried all three video ports, rf, monitor and aux, all give a black screen. Just wondering if it is fixable at all or if reseating the chips on the bottom adam board will have any affect. Thanks for everyone's help in advance! 

[NIAD]

You will need to disassemble the Memory Console to get to the multiple PCBs to give them a thorough cleaning and as you said, reseat all socketed chips.

 

Good Luck

[INTVCruise]

2 hours ago, NIAD said:

You will need to disassemble the Memory Console to get to the multiple PCBs to give them a thorough cleaning and as you said, reseat all socketed chips.

 

Good Luck

Thank you for the advice, quick question would a problem on the adam computer portion be preventing the colecovision portuon from booting? If i try the colecovision motherboard on the good adam i have is it possible it would boot up? Just asking since I noticed there no socketed chips on the CV board if I am remembering correctly. Thanks in advance!

[crisalan44]

I had this same exact problem on a Adam expansion model 3 that I bought a while back down to the humm and colecovison not working and all the same stuff you described. It was the Adam in my case and not the colecovision and if I remember correctly it had to do with a short on the power supply connections on the Adam motherboard it was shorting out the 12v I think it was and not sending enough power to run everything just enough to fire it up and humm. I removed the mother board and underneath where the plug is for the power supply it was shorting out and had some bad soldering on it. Cleaned it up removed the solder overflow causing it to short out and it fired right up. Hope this helps.

Edited July 18, 2020 by crisalan44

[NIAD]

19 hours ago, INTVCruise said:

Thank you for the advice, quick question would a problem on the adam computer portion be preventing the colecovision portuon from booting? If i try the colecovision motherboard on the good adam i have is it possible it would boot up? Just asking since I noticed there no socketed chips on the CV board if I am remembering correctly. Thanks in advance!

Depending on what the issue is on the Adam Logic Board or the little Power PCB. It’s really hard to say.

 

All systems that I had issues with, the problem was on the Adam Logic Board.

 

Pay close attention to the ribbon cable/connector that joins the two boards.

 

Yep, the CV Delta Board does not have any socketed chips. The Adam Logic Board usually has about 5 iirc.

 

[INTVCruise]

3 hours ago, crisalan44 said:

I had this same exact problem on a Adam expansion model 3 that I bought a while back down to the humm and colecovison not working and all the same stuff you described. It was the Adam in my case and not the colecovision and if I remember correctly it had to do with a short on the power supply connections on the Adam motherboard it was shorting out the 12v I think it was and not sending enough power to run everything just enough to fire it up and humm. I removed the mother board and underneath where the plug is for the power supply it was shorting out and had some bad soldering on it. Cleaned it up removed the solder overflow causing it to short out and it fired right up. Hope this helps.

Thank you for the suggestion Crisalan, I looked underneath the small power with the 9 pin connector, didn't see anything that could be causing a problem. 

[INTVCruise]

2 hours ago, NIAD said:

Depending on what the issue is on the Adam Logic Board or the little Power PCB. It’s really hard to say.

 

All systems that I had issues with, the problem was on the Adam Logic Board.

 

Pay close attention to the ribbon cable/connector that joins the two boards.

 

Yep, the CV Delta Board does not have any socketed chips. The Adam Logic Board usually has about 5 iirc.

 

I see, if I were to swap out the coleco board in my working adam and place it into the broken one would that be okay or is there a risk of damaging the known working board. If there is I'll probably just save myself the hassle of trying to fix it and part it out online. Thanks again! 

[NIAD]

There is always a risk involved with electronics especially when the issue is unknown. I have performed this transplant numerous times without any issues, BUT.........