Sears Intellivision-not working!

[SoundGammon]

Recently got the Sears version of the Intellivision.

 

Always wanted one because I love the look of it!

 

Anyway, when I power it up, all I get is a black screen, no game video or sound.

 

Using the rf output channel 3.

 

Any ideas where to start?

[Porte048]

Did you try channel 4?

 

 

Also, clean it up:

 

Contacts, different games, compressed air,

[SoundGammon]

Did all that!

[Porte048]

If youve already tried stuff, tell us! What else have you tried

[SoundGammon]

I'm going to pop it open this week-end and check the power supply.

 

I'm thinking the 5 volt supply is dead. I've seen a schematic awhile ago and do some checking!

 

Also, I've got 2 standard units to check it against!

[mr_me]

You can find the service manual and test voltages here.

https://console5.com/wiki/Intellivision

Also test the ribbon cable for continuity; be carefull with the ribbon cable, it's delicate.

 

The Sears Intellivision is no different than a model 2609. Remove the rf shield and give it a good visual inspection. Unless your TV gives a black screen with no signal, a black screen from Intellivision usually means the signal/channel is working but no cartridge program is running. So yes the first thing to check is the cartridge and cartridge port.

Edited April 4, 2018 by mr_me

[SoundGammon]

Looking at the schematic, looks like the rf unit gets it power from 12 volts, and I know that is working!

 

So my bet is the 5 volt supply isn't working.

[HunterZero]

Checking the power supply and 5 pin ribbon cable is always a good start. From my experience, the power board itself is usually good (there's just AC to DC bridge rectifier conversion, and 7805/7812 voltage regulators), it's the ribbon cable that disintegrates.

Do you get a flash on the screen when you press reset?

The Intellivision's cartridge connects directly to the main bus, so problems with the cartridge contacts eg dirt can cause black screen. A good clean with Deoxit is always a good idea.

Also check the 2 transistors Q1 and Q2 on the main board, as these drive the clock lines on the CPU.

Lastly, logic issues with the STIC, RA-3-9600 RAM or even the CPU can cause black screen. Carefully cleaning the legs and resocketing might help, otherwise replacement is the only option. At least you have a couple of other units, so you could swap ICs between them to troubleshoot (although this means cracking open the shielding on a working system).

- J

Edited April 9, 2018 by HunterZero

[ArcadeJunkie]

Wouldnt hurt to replace the caps while you have it open. I have fixed plenty of 2609s and they required a cap change or replacement transformer more than anything else.

[HunterZero]

Wouldnt hurt to replace the caps while you have it open. I have fixed plenty of 2609s and they required a cap change or replacement transformer more than anything else.

 

I have found that the SHOEI branded capacitors are actually good parts. That said, they are 35 year old electrolytics, so it is a good idea to replace them as preventative maintenance, and I did do this on my units. However all the old capacitors I pulled off the boards actually tested OK, and quality replacements for the larger power capacitor parts do cost several dollars (A$5.89 for the 2200uF 25V, and A$9.35 for the 10000uF 25V upgraded from 16V Nichicon branded from element14.com).

 

I did fix one unit that had one of the 0.1uF non-polarised glass caps at C13 blown (it had catastrophically exploded), that was presenting with a black screen.

 

YMMV...

 

- James

Edited April 12, 2018 by HunterZero