Nintendo 20EZ B+ unadjustable

Sirius

Member
Joined
Oct 4, 2010
Messages
246
Reaction score
1
Location
Ortonville, Michigan
I'm currently working on a 20 EZ as part of a tube swap. The B+ is at 140 volts and unadjustable. Chassis has a new flyback, b+ pot, 1090, vr and hot. Where to look next?
 
Iffy filter cap you mean the big cap in the power section of the chassis, yes I did. I did a complete cap kit first. As for IC 601, I replaced that also. Although given the unreliability of that part when new, it may be possible it's bad already? Is there a way to test them?
 
Ok, so I swapped back in the old ic601 and had no b+ and thought crap! Put the new one Back in and still had no b+ and thought double crap!! Then I swapped back in a old q901 and still no b+, then I realized that one of the leads from the power cord broke from the solder. I re-soldered it, now I get about 125 volts un-adjustable. The b+ pot will turn the voltage up higher but no lower than 125v.
 
my bet it is IC 601.

that is the same problem i have had in the past.

Peace
Buffett
What? Getting bad new stock? I've tried every part I got. I've bought 2 new hots and 2 new 1090's. Twice I've hooked up hot (properly) with the insulators and sleeves and had them short on the lower screw and blow the 4 amp fuse. That makes me wonder if their not bad now also. I swapped in a different hot and now the B+ is over 140v (was 125v) and not adjustable. That 5112 was $8 ($15 after shipping) from Twisty...if it's the problem, I don't see any point in buying another only to have that be bad too! Would be ok if I could test it to be sure? Can anyone say......UNCLE?
 
yup bad new stock i got 8 from bob in one order several years ago and all 8 were bad.
tested everyone in a chassis and the B+ would not adjust.

robbed one from another chassis and had a beautiful pic.
fully adjustable rock solid B+.

i did not even contact bob cause i did not want to hear the i sell no bad parts speech.


Peace
Buffett
 
Yeah, I've read over and over about the bad stock. I would reorder all three parts if I could get all three from the same person to save on shipping. As it stands right now, I can only get the hot and 1090 from Bob and the 5112 from Twisty. I wish had the electronics know how to design a simple circuit on a breadboard to test them. Now there's a project for someone? Would it be do-able?
 
I've been absolutely frustrated with the number of bad 5112 that I've come across. I've got them from multiple sources. Sometimes they work, and a lot of the time they do not.

I just wish that there was an easy way to bench test them. I've been thinking about taking an EZ chassis, soldering in a SIP strip, and plugging then in one by one. Seems like a heck of a waste of an EZ chassis.

Wish there was an easier way to just use a regular monitor in Nintendo cabs.
 
There is.

Mod a K7000 and install it.
cut down the shelf mount frame or find a vertical frame. or swap the tube into the sanyo frame.

when i tested the 5112's i got from bob i put in a machine pin socket on the chassis.

Peace
Buffett
 
Back
Top Bottom