Sencore LO-BOY Repair
 

My Sencore TV pattern generator won't show any picture. I can tell it tries but it's disguised behind massive hum bars.

Knowing this would be a cap issue, I have no idea where to start though:
http://img.photobucket.com/albums/v3...6.jpg~original

My first guess would be the big two section filter in the upper-right. Next, I'd replace the three axial electrolytics on the PCB.

Try to stay clear of those clear plastic metal foil caps in the middle of the board. Those are polystyrene caps which are very likely just fine and damage easily from excessive soldering iron heat.

How would I replace the big two section cap? I assume I can just rig together two electrolytic with their negative sides soldered together.

Yes, exactly.

Perfect, I should be able to do this then.

Interesting. I didn't know they made an AC powered version of those... I have one that is almost exactly the same, except that in place of the transformer and big filter cap and such, it has a couple battery tubes to hold 8 C cells.

You might mount one or two terminal strips and attach the caps to the strip. It will give you a connection point and a good physical mounting for the electrolytic capacitors. Your new capacitors will be very small in comparison to the original "firecracker" capacitor. You can even use the wires from the old electrolytic capacitor for connections to the new capacitors if you mount the strips in the right place. It should make a nice neat job. I think that even Radio Shack sells terminal strips.

Just a though.

There probably isn't even any need to mount a new terminal strip... just disconnect the wires going to the old cap, and mount the new caps where the wires were. It looks like the fourth terminal the right is the ground tie point, and the two terminals on the right end are the positive leads for the cap... with a bit of creative bending of the leads (and a bit of heatshrink to insulate them), it shouldn't be too hard to get the new caps to span that far.

I have the same Lo-Boy that Nick the 'Nole has. I repaired mine by replacing ONLY the electrolytic's on the board, but I'd bet that you also need to change the filter capacitors near the power transformer. I wired mine to work on a 12volt wall-wart power supply, and now it's quite stable!

I replaced all the regular looking electrolytic on the mainboard, and half the wax cap (I only have one cap that will work, so I replaced the half that my caps voltage rating is compatible with.)

We got picture!

https://scontent-b-mia.xx.fbcdn.net/...60546038_n.jpg

https://scontent-b-mia.xx.fbcdn.net/...74345314_n.jpg

https://scontent-a-mia.xx.fbcdn.net/...52024940_n.jpg

Looks good - glad you got it running :thmbsp: