Dim/fuzzy output on IIe

6 posts / 0 new
Last post
Offline
Last seen: 11 months 3 days ago
Joined: Oct 15 2016 - 04:58
Posts: 22
Dim/fuzzy output on IIe

Just picked up an Enchanced IIe, and it has a wierd problem - pretty low video output, and a bit fuzzy, connected to my Apple Monochrome monitor. My other IIe is crisp and much brighter. Any idea where to start troubleshooting?

Offline
Last seen: 8 hours 35 min ago
Joined: Jun 18 2010 - 13:54
Posts: 741
Start with the RCA connector.

Start with the RCA connector. Wiggle, twist and re-solder if it's intermittent. Otherwise, check 74LS10 at C5 as well as the video amplifier VA1.

CVT
CVT's picture
Offline
Last seen: 7 hours 39 min ago
Joined: Aug 9 2022 - 00:48
Posts: 998
jeffmazur wrote:... as well
jeffmazur wrote:

... as well as the video amplifier VA1.

 

Does it exist? I've never even seen a picture of an Apple IIe motherboard that has the VA1 footprint populated.

Offline
Last seen: 8 hours 35 min ago
Joined: Jun 18 2010 - 13:54
Posts: 741
 CVT wrote:jeffmazur wrote:..

 

CVT wrote:
jeffmazur wrote:

... as well as the video amplifier VA1.

 

Does it exist? I've never even seen a picture of an Apple IIe motherboard that has the VA1 footprint populated.

Yeah, I've only seen a similar part on the //c and //c+. But it looked like some of the //e's were provisioned for something like this. Maybe never implemented though.

Offline
Last seen: 11 months 3 days ago
Joined: Oct 15 2016 - 04:58
Posts: 22
Well, I don't have VA1, and I

Well, I don't have VA1, and I replaced the 74LS10 with my good one, and no change... The connector is fine, wiggling doesn' t change anything, but I did resolder just in case.

CVT
CVT's picture
Offline
Last seen: 7 hours 39 min ago
Joined: Aug 9 2022 - 00:48
Posts: 998
Check all the voltages on Q1

Check all the voltages on Q1 and Q2 (they are measured against ground):

 

 

 

Log in or register to post comments